Forest Worker Households in the NFPP: Enhancing Sustainable Livelihoods through Capital and Transformation

Abstract

The persistent conflict between strict conservation and community welfare highlights the growing need to address sustainable livelihoods in forest protection programs. The Natural Forest Protection Program (NFPP) is a comprehensive forest protection program spearheaded by the Chinese government. It is designed to facilitate the conservation and restoration of forest ecosystems through a range of interventions, including logging ban, management, tending, and afforestation efforts. Drawing upon longitudinal micro-level household survey data spanning five consecutive years from 2017 to 2021, this research quantifies the sustainable livelihood levels of frontline participants in the NFPP by examining two dimensions: livelihood capital stock and livelihood transformation capacity. Additionally, it investigates the internal differentiation phenomenon within this cohort. The findings suggest that forest worker households engaged in tasks related to forest management, tending, and afforestation are the frontline participants in the NFPP, in contrast to management, technical, and service personnel. Moreover, these forest worker households exhibit a pattern characterized by a higher livelihood capital stock but a lower livelihood transformation capacity compared to non-forest worker households. Furthermore, within forest worker households, there is a significant group differentiation phenomenon, resulting in inter-group differentials in the sustainable livelihood levels based on geographical and seniority stratification criteria. The developers of the global forest protection program should prioritize addressing the sustainable livelihood issues of frontline participants in the program, especially the real problem of mismatches between livelihood capital stock and livelihood transformation capacity. This can be achieved through designing income incentives, stimulating consumption, and other means to enhance the relatively disadvantaged position of frontline participants while balancing the coordination and fairness of the protection program based on the aspects of both protection and development.

1. Introduction

Forests cover nearly 31% of the Earth’s terrestrial surface, sustaining the livelihoods of approximately 1.6 billion people [1]. Nevertheless, human-driven forest resource exploitation, characterized by unsustainable practices, has engendered a surge in global natural disasters and public safety incidents. Such phenomena exacerbate pressures on ecosystem services and natural capital, thereby imperiling the livelihood security of human populations reliant upon these vital resources [2]. In confronting the formidable challenges posed by forest degradation and livelihood insecurities, developing countries have endeavored to institute diverse forms of forest protection programs, including national parks and nature reserves [3]. However, the imposition of stringent forest conservation measures often conceals apprehensions regarding their impact on the livelihood strategies and levels of local forestry communities [4]. Amidst the contentious discourse surrounding the governance paradigm of “intensive protection, limited development”, the assessment of livelihood concerns among participants in forest protection programs assumes heightened significance.

As a large-scale forest protection program spearheaded by the Chinese government [5], the NFPP similarly faces the dilemma of balancing protection and development. The NFPP was initially piloted in northeast China and inner Mongolia state-owned forest region (NSFR) in 1998, gradually extending its scope to encompass natural forest areas nationwide. This program was implemented in two phases: Phase I (2000–2010) and Phase II (2011–2020). The core objective of this program is to address the degradation of natural forests resulting from excessive logging during the 1980s and 1990s, particularly in the upper reaches of the Yangtze River Basin, the Songhua River Basin, and the Nenjiang River Basin within China [6]. On the one hand, the NFPP endeavors to achieve the protection and restoration of natural forest resources through a combination of measures including timber reduction, noncommercial cutting, logging ban, management, tending, and afforestation. On the other hand, the stringent forest conservation measures outlined above exert profound impacts on local forestry communities. Preceding the implementation of the NFPP, these communities were primarily employed in extractive roles such as logging, processing, and transportation. However, subsequent to the NFPP’s implementation, a pronounced shift has been observed toward protective roles including forest management, tending, and afforestation activities. This transition has consequently induced alterations in livelihood strategies and levels within forestry community households. Consequently, conducting research on the welfare levels and trajectories of the participants within the NFPP holds critical significance in evaluating the potential trade-offs between stringent conservation efforts and the promotion of welfare.

The existing literature predominantly addresses this issue through several key dimensions. Namely, (1) utilizing unidimensional indicators to assess the welfare levels of forestry community households within the NFPP implementation region. Such inquiries primarily focus on employing household income capacity or consumption capability as proxies for evaluating the welfare levels of forestry community households. Certain scholars have scrutinized and evaluated the effects of NFPP implementation on the income channels and structure of local forestry community households [7,8], while others have conducted further investigations into the impact dynamics of stringent conservation measures (such as noncommercial cutting and logging ban) during the NFPP process on household income levels [9,10]. (2) Utilizing multidimensional indicators to assess the welfare levels of forestry community households within the NFPP implementation region. In recent years, scholars have increasingly favored the adoption of multidimensional indicators over unidimensional ones to gauge the welfare levels of forestry community households. Multidimensional indicators, encompassing dimensions such as capability, power, and resources, offer a more effective and comprehensive means of quantifying the living standards and circumstances of sampled households, compared to unidimensional indicators like income and consumption [11,12,13,14]. In contrast to alternative approaches such as subjective well-being assessments [15], the establishment of household wealth indices [16], and feasible capability welfare evaluations [17], the application of sustainable livelihood theory to quantitatively assess the welfare levels of sampled households has garnered broader recognition and dissemination. Consequently, a multitude of scholars have engaged in empirical examinations centered on the sustainable livelihood levels of forestry community households [18,19]. (3) Utilizing poverty theory to discern vulnerable groups arising within the NFPP implementation region. This focus is evidenced in empirical research pertaining to income poverty [20], multidimensional poverty [21], household vulnerability [22,23], and other pertinent aspects concerning forestry community households.

Upon retrospective analysis of the extant literature, we discerned the presence of the following limitations. Primarily, research endeavors conventionally opt to encompass all forestry community households within the NFPP implementation region, thereby lacking a targeted focus on the frontline participants in the NFPP. The indiscriminate assessment of all types of forestry community households will inevitably result in an overestimation of welfare measurement levels, thereby impeding the accurate capture and measurement of the welfare levels of frontline participants in the NFPP. Additionally, although the utilization of multidimensional indicators to supplant unidimensional indicators in appraising the welfare levels of sampled households has gained traction, it frequently limits itself to the assessment of the capital stock of sampled households sustainable livelihood levels. There is an absence of contemplation regarding the feasibility and degree to which livelihood capital stock can be converted into income capacities and consumption capacities. Finally, the scholarly focus on vulnerable groups addresses the principles of social justice within environmental conservation [24]. Nevertheless, the identification criteria for vulnerable groups based on poverty theory are no longer suitable within the context of China’s comprehensive eradication of absolute poverty. Moreover, they are incapable of capturing the significant social stratification phenomenon emerging within local forestry communities following the implementation of the NFPP.

In order to address the limitations of current research, this study opts for the NSFR, the core implementation region of the NFPP, as the study area. It selects forestry community households situated within the NSFR from 2017 to 2021 as the study subjects. The primary contributions of this manuscript are as follows. (1) A targeted focus on the frontline participants in the NFPP to mitigate the potential risk of overestimating the welfare levels of NFPP participants. (2) A comprehensive consideration of both livelihood capital stock and livelihood transformation capacity. Introducing livelihood transformation capacity as a novel technical indicator enables the assessment of the extent to which the livelihood capital stock of sampled households can be converted into income capacity or consumption capacity, thus circumventing the limitations associated with solely conducting livelihood capital stock accounting. (3) The substitution of poverty theory with social stratification theory to explore internal differentiation issues among frontline participants, thereby broadening the definition of vulnerable groups. (4) The utilization of longitudinal data from forestry community households spanning from 2017 to 2021 to address the common limitations of the existing literature, which predominantly relies on cross-sectional data and hence faces challenges in capturing trends in sustainable livelihood levels. The primary objective of this study is to precisely discern the frontline participants in the NFPP, specifically delineating the types of forestry community households actively involved in the protection and restoration of natural forest resources. This is accomplished by devising two technical indicators, namely livelihood capital stock and livelihood transformation capacity, serving to gauge the sustainable livelihood levels and trajectories of the participating cohorts. Additionally, social stratification theory is leveraged to scrutinize the phenomenon of internal differentiation prevalent within these cohorts.

The subsequent sections of this manuscript are structured as follows: Section 2 delineates the conceptual underpinnings and research framework. Section 3 outlines the data sources and methodology utilized in this investigation. Section 4 proceeds with an analysis based on the statistical findings derived from quantitative data collection. Lastly, Section 5 encompasses the discussion and conclusion.

2. Concept and Framework

2.1. Concept

2.1.1. Forestry Community Households and Classification

Forestry community households typically include families residing within regions abundant in forestry resources whose livelihood activities are reliant upon forest resources [25]. The study area encompasses the key state-owned forest region in northeast China and inner Mongolia, colloquially referred to as the “NSFR”. This region comprises the Daxing’anling and Xiaoxing’anling Mountains and the Changbai Mountain state-owned forest region, located across the provinces (autonomous regions) of Heilongjiang, Jilin, and inner Mongolia. Collectively, these areas encompass a total operating area of 32.7412 million hectares, constituting 3.41% of the nation’s total land area. The NSFR, as a key ecological functional zone in northeast China, is characterized primarily by the following three features: (1) Regarding forest resources, natural forests constitute the primary component. Specifically, natural forests cover an extensive area of 25.4164 million hectares, representing 93.19% of the total, while artificial forests encompass 1.8583 million hectares, constituting 6.81% of the total. (2) Regarding organizational structure, a distinctive operational framework of “government-enterprise-community” has been established. The NSFR is administered and operated by six forest industry conglomerates, namely Longjiang Forest Industry Group, Yichun Forest Industry Group, inner Mongolia Forest Industry Group, Daxing’anling Forestry Group, Jilin Forest Industry Group, and Changbai Mountain Forest Industry Group. These conglomerates collectively supervise 87 state forest enterprises (SFEs) tasked with managing production operations and community development initiatives within their designated implementation region. (3) Regarding community demographics, forestry community households affiliated with SFEs predominate. Subsequent to the implementation of the NFPP, there have been substantial transformations in the occupational roles and duties of forestry community households affiliated with SFEs, transitioning from forest exploitation to forest conservation endeavors. This transition has indirectly impacted the livelihood strategies and livelihood levels of forestry community households. Given that the primary aim of the NFPP is to protect and restore natural forest resources through measures such as forest management, tending, afforestation, remediation, and restoration of degraded forest, frontline participants in the NFPP primarily comprise forest workers engaged in protective roles. Forest workers are defined herein as employees of SFEs tasked with activities related to forest management, tending, or afforestation. This study categorizes households into two distinct groups based on the presence of forest workers: forest worker households and non-forest worker households. The former group is directly implicated in the efficacy of NFPP implementation concerning the protection and restoration of natural forest resources, while the latter group predominantly occupies auxiliary roles such as management, logistics, technical, and service positions. Furthermore, forest worker households can be further delineated based on the quantity of forestry workers, including single-forest-worker households and double-forest-worker households (according to estimations derived from forestry community households data spanning from 2017 to 2021, with each household accommodating a maximum of two forestry workers). This study seeks to estimate and assess the sustainable livelihood levels and trends among forest worker households versus non-forest worker households, thereby elucidating inter-group differentials.

2.1.2. Livelihood Capital Stock Based on Sustainable Livelihood Theory

Assessing the welfare levels of sample households based on sustainable livelihood theory is a prevalent approach in contemporary scholarly research [26]. The sustainable livelihood theory is a comprehensive analytical framework designed to emphasize the livelihood strategies and resource utilization strategies adopted by individuals or households to achieve sustainable livelihoods within specific social, economic, and environmental contexts [27]. This theory serves as a valuable tool for policymakers to gain nuanced insights into the livelihood conditions of individuals or households, thereby enabling the development of more efficacious intervention strategies aimed at fostering livelihood enhancement and sustainable development.

Drawing upon the Sustainable Livelihood Approach (SLA) delineated by the Department for International Development (DFID), this study undertakes the quantification of livelihood capital stock through the utilization of the pentagonal structure delineating livelihood capital [28]. Livelihood capital denotes the aggregation of resources available to households for the sustenance of their livelihoods, primarily comprising human capital, natural capital, financial capital, physical capital, and social capital [29,30]. The livelihood capital stock is consequently derived as a comprehensive score computed based on the aforementioned evaluation indicators of livelihood capital. For forestry community households in the NSFR, human capital stock denotes the knowledge, skills, labor capacity, and health status employed for livelihood activities [31]. Natural capital stock refers to the inventory of natural resources utilized for sustaining livelihoods [32]. Due to the extensive distribution of forest resources and pronounced seasonal dynamics inherent in the natural attributes, coupled with the societal attributes of forest resource management modalities, the natural capital stock constitutes the fundamental livelihood capital stock for forestry community households in the NSFR [33]. Financial capital stock encompasses cash, deposits, and accessible loans utilized for the acquisition of consumer goods and production inputs [31]. Physical capital stock encompasses the essential means of production and infrastructure employed for livelihood maintenance. For forestry community households situated in the NSFR, this dimension holds direct implications for residential surroundings and the standard of living [32]. Social capital stock pertains to the social resources leveraged to pursue livelihood objectives [31]. Sufficient social capital stock can mitigate the pressure and repercussions confronted by forestry community households arising from natural and anthropogenic risks [34]. Consequently, leveraging longitudinal data collected from surveys conducted among forestry community households enables the computation of capital stock levels across the aforementioned five dimensions, thereby facilitating the aggregation to ascertain the livelihood capital stock level of the sample households.

2.1.3. Livelihood Transformation Capacity Based on the Capability Approach

In the process of structuring this article, it came to our attention that the existing literature predominantly focuses on the assessment of livelihood capital stock, with a notable absence of deliberation on the extent to which livelihood capital stock can be translated into income capacities or consumption capacities. To redress the aforementioned deficiencies, this study develops a novel index of livelihood transformation capacity grounded in Sen’s Capability Approach. The capability approach underscores the procedural aspect whereby individuals attain freedom, specifically delineating the process of converting individual capabilities into functional activities [35]. According to this theoretical framework, it is apparent that an individual’s quality of life is contingent not only upon the quantity of resources they possess but also upon their capacity to convert these resource stocks into a satisfactory standard of living. This principle similarly applies to households [12,13]. Drawing upon the aforementioned theoretical concepts, we introduce a novel technical metric termed the livelihood transformation capability index in this study. This index serves to elucidate the capacity of sample households to convert their accrued livelihood capital stock into tangible livelihood outcomes.

The essence of livelihood outcomes is most succinctly reflected in the income and consumption results of sampled households, owing to the fact that income provides an authentic portrayal of household living conditions [36]. However, solely relying on income as a metric for gauging household livelihood outcomes may lack comprehensiveness. Hence, it supplements income with consumption serves to offer a more holistic evaluation, as consumption can elucidate welfare disparities among households [37]. By corroborating income measurement outcomes with consumption, a more robust assessment can be achieved. The computed livelihood capital stock obtained in Section 2.1.2 signifies the magnitude of resources possessed by forestry community households, with income and consumption levels serving as indicators of the standard of living for these households. Livelihood transformation capability is defined as the capacity of livelihood capital stock to be translated into income and consumption. Specifically, it is computed as the household’s livelihood outcome (either income or consumption level) divided by the livelihood capital stock (comprising the results of livelihood capital assessment across the five dimensions).

In summary, this study follows the conventional SLA, employing livelihood capital stock to quantify the quantitative aspect of sustainable livelihood levels. Furthermore, drawing upon Sen’s Capability Approach, a novel indicator is devised to represent the qualitative dimension of sustainable livelihood levels. Herein, livelihood transformation capability is utilized as a metric to delineate the transformation of capital stock into outcomes.

2.2. Research Framework

The central objective of this study is to accurately delineate the frontline participants in the NFPP and to comprehensively assess their sustainable livelihood levels through the quantitative evaluation of livelihood capital stock and livelihood transformation capability. Additionally, it aims to delve into the internal differentiation phenomenon prevalent within this cohort (see Figure 1). To address these objectives, the research unfolds through the following three-step approach: the identification of frontline participants in the NFPP; the estimation of the dimensions and dynamics of livelihood capital stock and livelihood transformation capacity within forestry community households; and the exploration of the internal differentiation phenomenon among frontline participants in the NFPP.

Step 1 entails the identification of frontline participants in the NFPP. This study categorizes forestry community households into two primary groups based on the presence and quantity of forest workers: forest worker households and non-forest worker households. Among these, forest worker households are further subclassified into single-forest-worker households and double-forest-worker households. The contention of this study posits forest workers, engaged in tasks such as forest management, tending, afforestation, remediation, and restoration of degraded forest, as the authentic frontline participants in the NFPP implementation process. Ensuring and enhancing the livelihoods of this cohort not only aligns with principles of environmental justice but also corresponds with the objectives of various global forest conservation policies, which prioritize the welfare of vulnerable groups.

Step 2 entails estimating the dimensions and dynamics of livelihood capital stock and livelihood transformation capacity within forestry community households. This involves the construction of a livelihood capital stock index system comprising human, natural, financial, physical, and social capital stock dimensions. Subsequently, the livelihood capital stock of forestry community households is quantified, with an analysis of the disparities in livelihood capital stock between forest worker households and non-forest worker households, elucidating the underlying reasons for these disparities. Concurrently, a framework for assessing livelihood transformation capacity is formulated and applied to determine the ability of households to translate their livelihood capital stock into income capabilities and consumption capabilities. Discrepancies in livelihood transformation capacity between forest worker households and non-forest worker households are investigated, offering insights into the factors driving these variations. Building upon these analyses, a deeper exploration is conducted to ascertain whether the observed disparities in the computation results of livelihood capital stock and livelihood transformation capacity between forest worker households and non-forest worker households exhibit consistent patterns.

Step 3 entails the exploration of internal differentiation phenomena among frontline participants in the NFPP (forest worker households). Departing from the conventional framework of poverty theory, this study adopts social stratification theory as an alternative lens to examine the internal differentiation phenomena within forest worker households, thereby expanding the conceptualization of vulnerable groups. Of particular interest are two prominent manifestations of social stratification observed within forestry community households within the NSFR subsequent to the NFPP’s implementation: geographical stratification and seniority stratification. Geographical stratification engenders variations in the residential and sociocultural milieus among sampled households, whereas seniority stratification precipitates distinctions in job preferences and income remuneration among the same cohort (as elaborated further in Section 3.2.3). Consequently, this paper conducts a stratified grouping of forest worker households based on geographical and seniority stratification criteria for quantitative analysis, with a focus on internal differentiation phenomena within these households concerning livelihood capital stock and livelihood transformation capacity across diverse stratification parameters. This analytical endeavor seeks to uncover the heterogeneous repercussions of the NFPP on forest worker households.

3. Materials and Methods

3.1. Data Sources

The data utilized in this study concerning forestry community households originated from the “Livelihood Monitoring in Northeast and Inner Mongolia state-owned forest region” survey project conducted collaboratively by the National Forestry and Grassland Administration of China and northeast Forestry University spanning the period from 2017 to 2021. The primary aim of this survey project was to assess the standard of living of forestry community households engaged in the NFPP within the NSFR. Specifically, households considered as participants in the NFPP were operationally defined as those containing at least one member employed within SFEs. The present study utilized a multi-stage random sampling method to obtain the sample data from the forestry community households. Firstly, in each SFE’s operating area, two forest farm communities on the mountain and one urban community down the hill were equally sampled. Subsequently, 10 samples were randomly selected from the employee list of each of the three communities. The survey was conducted through computer-assisted telephone interviewing technology, utilizing structured interviews to collect responses to the survey questionnaire from the respondents. The surveyors further acquired relevant information about the household members during the interview process. The data encompassed demographic characteristics (comprising age, gender, and marital status), livelihood capital details (comprising human, natural, financial, physical, and social capital indicators), and household living conditions (comprising income and consumption patterns). Subsequent to data collection from sample households, livelihood capital information underwent quantification to ascertain the livelihood capital stock of forestry community households. Concurrently, income levels and consumption patterns were analyzed to compute livelihood transformation capacity. After filtering out samples not meeting the research criteria, the final effective sample sizes amounted to 1937 for 2017, 2154 for 2018, 2181 for 2019, 2131 for 2020, and 2010 for 2021.

3.2. Research Methods

3.2.1. Methods for Livelihood Capital Stock

The measurement of livelihood capital stock reflected the quantification of available resources across five dimensions—namely, human capital, natural capital, financial capital, physical capital, and social capital—pertaining to sampled households. Specific indicators were refined to suit the empirical realities of forestry community households within the NSFR, while also considering data availability. For instance, human capital stock indicators encompassed variables such as educational attainment, health condition, number of laborers, and engagement in occupational and technical training among sampled households. Natural capital stock was evaluated through measures of agricultural land resources and forest land resource utilization by these households. Financial capital stock was appraised according to the deposits and loans among the sampled households. The assessment of physical capital stock involved metrics such as the building area and the valuation of durable consumer goods owned by the households. Social capital stock was gauged using factors such as the number of household members employed within SFEs and the amount spent by the household on gift money. By employing the comprehensive evaluation framework outlined in

Table 1. Evaluation framework of livelihood capital stock indicators.

Livelihood Capital Stock	Proxy Indicators	Descriptions	Attributes
Human Capital Stock	Educational Attainment	Household average educational years	Positive
	Health Condition	Count of afflicted household members	Negative
	Number of laborers	Number of household laborers	Positive
	Occupational and Technical Training	Have household members participated in vocational and technical training? Yes = 1; No = 0.	Positive
Natural Capital Stock	Agricultural Land Resources	Are household members engaged in agricultural production and management? Yes = 1; No = 0.	Positive
	Forest Land Resources	Are household members engaged in agroforestry production and management? Yes = 1; No = 0.	Positive
Financial Capital Stock	Deposits	Aggregate household bank deposits	Positive
	Loans	Aggregate household loans	Positive
Physical Capital Stock	Building Area	Area of the household’s permanent residence	Positive
	Valuation of Durable Consumer Goods	Amount of household expenditure on household appliances and durable consumer goods	Positive
Social Capital Stock	Social Network	Number of household members employed in SFEs	Positive
	Gift Money Expenditure	Amount spent by the household on gift money	Positive

, this study ensured a thorough capture of the livelihood conditions and resource availability for forestry community households within the NSFR.

The foundational task in quantifying the livelihood capital stock involved the assignment of appropriate weights to each indicator. This study followed the common practice documented in the existing literature, which involves assigning equal weights to sustainable livelihood considerations [38,39]. Specifically, this study assigned equal weights to the capital stock across the five dimensions.

The specific steps for calculating the livelihood capital stock were as follows. Initially, the 12 statistical indicators across the five dimensions were standardized to dimensionless values ranging from 0 to 1.

The positive indicators are

$$Z_{ij}=(X_{ij}-{min}_{X_{ij}})/({max}_{X_{ij}}-{min}_{X_{ij}})$$

(1)

The negative indicators are

$$Z_{ij}=({max}_{X_{ij}}-X_{ij})/({max}_{X_{ij}}-{min}_{X_{ij}})$$

(2)

In this context, Z_ij denotes the score value of the indicator subsequent to dimensionless standardization, X_ij represents the original value of the indicator, minX_ij signifies the minimum value of the indicator, and maxX_ij denotes the maximum value of the indicator.

Subsequently, the weights were multiplied by the scores of the respective indicators and aggregated, yielding the livelihood capital stock index for sampled households. The precise calculation formula is articulated as follows:

$$Z=\sum _{i=1}^5\sum _j^n{W}_{ij}{Z}_{ij}$$

(3)

In Equation (3), Z denotes the livelihood capital stock index, W_ij represents the weight assigned to the j indicator within the i category of livelihood capital stock, Z_ij signifies the standardized value of the j indicator within the i category of livelihood capital stock, and n indicates the total number of indicators.

3.2.2. Methods for Livelihood Transformation Capacity Measurement

Based on the preceding exposition, it becomes apparent that the livelihood capital stock index Z merely serves as a proxy for the scale of livelihood capital stock within the sampled households. This study, however, placed greater emphasis on the extent to which the aforementioned livelihood capital stock can be efficiently converted into tangible livelihood outcomes for the sampled households, specifically addressing the livelihood transformation capacity. These outcomes were delineated into income and consumption categories, with income livelihood transformation capacity denoting the ability of livelihood capital stock to translate into income levels. Essentially, this represents the disposable income level procurable by households through their extant stock of livelihood capital stock. This is computationally formulated as follows

$$T_a=\mathrm{I}/Z$$

(4)

In Equation (4), the variable T_a denotes the income livelihood transformation capacity, I represents the per capita income of the household, and Z signifies the livelihood capital stock index. The per capita income of the household is construed as the quotient of the total household income received by the household population. Notably, the total household income encompasses four distinct facets, namely wage income, entrepreneurial income, property income, and transfer income.

The consumption livelihood transformation capacity pertains to the capacity of livelihood capital stock to be translated into consumption levels. It addresses the degree to which households, leveraging their extant livelihood capital stock, can fulfill their capacity to afford both material goods and intangible products. The computational formula for this aspect is outlined as follows

$$T_b=\mathrm{C}/Z$$

(5)

In Equation (5), the variable T_b denotes the consumption livelihood transformation capacity, C represents the per capita consumption of the household, and Z denotes the livelihood capital stock index. The per capita consumption of the household is defined as the ratio of total household consumption to the household population. This encompasses a comprehensive array of expenditure categories, including but not limited to food, clothing, education, daily necessities, housing, transportation, communication, cultural and entertainment expenses, household equipment and services, medical care, transfer payments, and entrepreneurial expenditures, totaling eleven distinct items.

3.2.3. Study on Internal Differentiation Phenomena Based on Social Stratification Theory

Social stratification theory delineates the subdivision of the overall populace into distinct subgroups predicated on criteria such as wealth status and social standing [40]. Stratification elucidates the relative differentials among these groups concerning wealth status, social standing, and related dimensions [41,42]. Social stratification theory provides multidimensional options for investigating internal differentiation phenomena within populations. The distinguishing characteristic of forestry community households lies in the multifaceted interactions between human activities and forest resources, encapsulated by the concept of “forest dependency” relations [43,44]. Research findings indicate that the implementation of NFPP has brought about discernible alterations in the outward expressions of this “forest dependency” dynamic. Within the purview of the NSFR, forestry community households have exhibited a gradual transition in their strategies pertaining to the utilization of natural forest resources, shifting from a paradigm of “commercial exploitation” toward one of “comprehensive conservation”. Furthermore, the dependency relationship between the human agent and the forest object has undergone a transformation from a model characterized by “consumption” to one of “symbiosis”. This structural metamorphosis within the socio-economic ecological systems primarily relies on forest resources within the NSFR that has engendered two distinctive typologies of social stratification phenomena.

One such phenomenon is geographic stratification. Forestry communities within the NSFR are primarily categorized into two distinct types: forest farm communities on the mountain and urban communities down the hill. Forest farm communities on the mountain are characterized as small-scale production-oriented forestry settlements established atop mountains by SFEs to facilitate timber harvesting, transportation, and related production activities. Conversely, urban communities down the hill are situated at the foothills and constitute a town-type forestry community. They serve as the locus for the administrative and service institutions of SFEs, concurrently acting as the central nexus for local residents’ commercial endeavors and primary habitation. Following the implementation of the NFPP, the original production functions of forest farm communities on the mountain, particularly in facilitating timber harvesting and transportation from natural forests, experienced a gradual decline. This, coupled with their remote geographic positioning, has contributed to a widening gap between forest farm communities on the mountain and urban communities down the hill concerning population size, road infrastructure quality, the provision of basic services, and levels of healthcare and education. Consequently, this study proposed grouping communities based on their geographical location to address the disparities in sustainable livelihood levels resulting from geographic positioning.

Another phenomenon is seniority stratification. Seniority stratification refers to disparities observed among on-duty personnel of SFEs based on the year of their entry into employment, which manifest in job selection, salary remuneration, workplace allocation, and residential circumstances. The fundamental nature of seniority stratification is rooted in both occupational and age-related stratifications, arising from the internal restructuring and job transfer mechanisms implemented within SFEs subsequent to the implementation of the NFPP. Specifically, with the emergence of the “forest resource crisis” during the 1980s and 1990s due to overexploitation, SFEs began to adopt NFPP-driven measures aimed at enterprise restructuring and workforce rationalization. This resulted in a substantial portion of traditional industry workers facing decisions regarding one-time resettlement or job transition. For employees who commenced their tenure within SFEs prior to the initiation of the NFPP’s pilot programs (pre-1998), many experienced the aforementioned reform processes and subsequently transitioned into frontline forestry roles such as forest management, tending, and afforestation. Consequently, this study investigated seniority stratification by stratifying individuals based on their commencement of employment in SFEs before or after 1998.

In summary, geographical stratification introduces disparities among sampled households regarding their residential and social environments, whereas seniority stratification engenders differences in job selection and salary income within these households. This study employed grouping based on both geographical and seniority stratification to delve deeper into the inter-group differentials in livelihood capital stock and livelihood transformation capacity across frontline participants. The objective was to unearth the heterogeneous effects of the frontline participants in the NFPP.

3.2.4. Identifying Inter-Group Differentials Based on Analysis of Variance

Analysis of variance (ANOVA) was proposed by the renowned British statistician and biologist Ronald A. Fisher in the 1920s. This statistical method is extensively employed in the realm of discerning inter-group differentials [45,46,47]. Its primary objective is to investigate the association between a continuous dependent variable and categorical independent variables. Through comparing the means of two or more datasets, it serves to ascertain the presence of statistically significant differences among them [48]. Based on the number of independent variables selected, ANOVA can be further delineated into three types: one-way ANOVA, two-way ANOVA, and multi-way ANOVA. Considering that this study primarily focuses on comparing inter-group differentials based on a single grouping criterion (e.g., utilizing “the quantity of forest workers in forestry community households” as the grouping criterion), it pertains to the paradigm of one-way ANOVA measurement.

The measurement paradigm of one-way ANOVA principally encompasses the following three steps:

(a)

State the hypotheses. Null hypothesis (H₀) is “All group means are equal (μ1 = μ2 = μ3 = … = μk)”. Alternative hypothesis (H_a) is “At least one group mean is different.”;

(b)

Calculate the ANOVA.

$${df}_{between}=K-1$$

(6)

$${df}_{within}=N-K$$

(7)

$$M{S}_{between}=S{S}_{between}/d{f}_{between}$$

(8)

$$M{S}_{within}=S{S}_{within}/{df}_{within}$$

(9)

$$F=M{S}_{between}/M{S}_{within}$$

(10)

The Sum of Squares Total (SST) includes the Sum of Squares Between (SSB) and Sum of Squares Within (SSW). Here, the Sum of Squares Total (SST) represents the total variation in the data; the Sum of Squares Between (SSB) represents the variation due to the interaction between the different groups; and the Sum of Squares Within (SSW) represents the variation within each group. In Equation (6), the Degrees of Freedom (df) represent the number of independent values, where K is the number of groups; in Equation (7), N is the total number of observations; in Equations (8) and (9), mean squares (MS) represent the average variation (SS divided by the corresponding df); and in Equation (10), F-Statistic represents the ratio of mean squares.

(c)

Bonferroni multiple-comparison test. Following the computation of the analysis of variance results, the Bonferroni multiple-comparison test is subsequently applied for post-hoc comparisons. Its objective is to explore the discernment of differences between each group.

Based on the outlined research methodology, this study employs One-Way ANOVA to conduct inter-group comparisons. These comparisons encompass two main aspects: firstly, assessing the inter-group differentials in livelihood capital stock and livelihood transformation capacity among various types of forestry community households (single-forest-worker households, double-forest-worker households, and non-forest worker households), and secondly, investigating the inter-group differentials in livelihood capital stock and livelihood transformation capacity among forest worker households, stratified based on geographical and seniority. Moreover, the Bonferroni multiple-comparison test is utilized for adjustment and correction, aiming to ascertain the statistical significance of the inter-group differentials.

4. Results and Analysis

4.1. Measurement Results of Livelihood Capital Stock

Figure 2 presents the computed results of livelihood capital stock for various categories of forestry community households. Over the period from 2017 to 2021, there is an observable trend of a fluctuating increase in livelihood capital stock across different types of households. The ANOVA test reveals statistically significant differences in the influence of various types of forestry community households on livelihood capital stock. These disparities are observed to be significant at the 1% significance level. Notably, the livelihood capital stock of forest worker households surpasses that of non-forest worker households (with an annual mean of 0.267 > 0.259). Moreover, double-forest-worker households exhibit a higher livelihood capital stock compared to single-forest-worker households (with an annual mean of 0.299 > 0.261). The Bonferroni multiple-comparison test serves as an additional validation of the aforementioned findings. A preliminary inference can be drawn. Within forestry community households in the NSFR, the magnitude of household livelihood capital stock correlates positively with the scale of family members engaged in frontline roles within SFEs, specifically the forest worker population. One conceivable explanation is that, subsequent to the implementation of the NFPP, the core business activities of SFEs underwent a transition from “timber harvesting, processing, and transportation” to “forest management, tending, and afforestation”. Consequently, forest workers have emerged as the frontline participants in the NFPP and the workforce of SFEs. Many individuals from traditional industries have transitioned to forest work through job reallocations during the NFPP implementation period. These individuals often possess extensive work experience and have long-standing residency in the NSFR, thereby scoring relatively higher in metrics such as human capital and natural capital. This, in turn, manifests as the superior livelihood capital stock of forest worker households compared to that of non-forest worker households, as evidenced by the computation results.

In order to corroborate the aforementioned claims, this study employs ANOVA to conduct inter-group differentials, further integrating five sub-dimensions of the livelihood capital stock evaluation index system. The analysis reveals significant differences among various types of forestry community households in terms of human capital stock, natural capital stock, physical capital stock, and social capital stock (refer to Figure 3 for comparative results).

Concerning human capital stock, forest worker households demonstrate a progressive trend, exceeding that of non-forest worker households. Notably, double-forest-worker households exhibit the highest human capital stock index (with an annual average of 0.199) and the most substantial increase (15.846%), while single-forest-worker households follow suit (with an annual average of 0.178), albeit with a more modest increase (10.928%). These observations signify that even amidst prolonged exposure to challenging operational environments, forest worker households boast significant richness in human capital stock, encompassing dimensions such as education, health, quantity, and skills. This phenomenon is attributed to the abundant forest resources within the NSFR, where forest worker households heavily rely on forestry-related livelihoods, underscoring the paramount importance of labor resources [49]. Traditional industry workers with extensive forestry experience and skill sets are tactically deployed to frontline participants in the NFPP through job reallocation, thereby engaging in conservation-oriented forestry endeavors such as management, tending, and afforestation.

Concerning natural capital stock, forest worker households exhibit higher levels compared to non-forest worker households. Specifically, double-forest-worker households experienced the most pronounced decline in their natural capital stock index (a decrease of 45%), with levels falling below those of single-forest-worker households in 2019. Conversely, single-forest-worker households exhibit a more gradual decline in their natural capital stock index (a decrease of 18.571%), maintaining a trajectory consistent with that of double-forest-worker households. These findings elucidate that forest worker households boast the highest levels of natural capital stock, albeit exhibiting a characteristic pattern of significant decline. This trend stems from the predominant engagement of forest worker households in activities such as forest management, tending, and afforestation, which heavily rely on forest and arable land resources for sustenance. Relative to non-forest worker households, forest worker households possess a more substantial reservoir of natural capital stock. However, with the initiation of the NFPP, SFEs have progressively implemented measures such as timber reduction, noncommercial cutting, and logging ban. Consequently, the forest-based economy, encompassing activities like agroforestry, animal husbandry, and non-timber forest product collection, has suffered severe setbacks, leading to a rapid decline in the proportion of forestry community households engaged in these productive and operational endeavors.

Concerning financial capital stock, forest worker households and non-forest worker households exhibit intertwined upward trajectories in their respective indices. Notably, double-forest-worker households demonstrate the highest financial capital stock index (with an annual mean of 0.019), characterized by the most significant growth rate (an increase of 82.517%). Conversely, single-forest-worker households manifest the lowest financial capital stock index (with an annual mean of 0.018), marked by a more gradual growth rate (an increase of 45.946%). These outcomes underscore that the implementation of the NFPP has afforded forestry community households stable avenues for transfer payments and employment income, thereby fostering an escalating frequency of financial transactions, including borrowing and depositing, within these households.

Concerning physical capital stock, the physical capital stock index of forest worker households exhibits a general upward trajectory, yet it remains subordinate to that of non-forest worker households. Specifically, double-forest-worker households manifest the lowest physical capital stock index (averaging 0.012 annually), while single-forest-worker households exhibit relatively higher indices (averaging 0.014 annually), demonstrating a notable and statistically significant upward trend characterized by the most substantial increase (75.229% growth). These findings suggest a burgeoning physical capital accumulation within forest worker households, concomitant with improvements in housing standards and living conditions. Nonetheless, in comparison to their non-forest worker households, physical capital accumulation within forest worker households remains comparatively deficient. This phenomenon can be attributed to the relatively modest production and subsistence standards prevalent among forest worker households, where a considerable portion of income is necessitated for domestic expenditure, consequently limiting the physical capital accumulation.

Concerning social capital stock, the social capital stock index of forest worker households exhibits a general downward trend and this trend is consistent with the variation observed in the social capital stock index of non-forest worker households. After experiencing a slight increase from 2017 to 2020, a substantial downturn occurred from 2020 to 2021. Notably, double-forest-worker households present the highest social capital stock index (with an annual mean of 0.056), while single-forest-worker households display the lowest index (with an annual mean of 0.038). These findings suggest that, in contrast to non-forest worker households, forest worker households predominantly consist of seasoned forestry personnel. Situated within geographically secluded forest regions characterized by strong familial network homogeneity, they possess more extensive and intricate interpersonal networks.

4.2. Measurement Results of the Livelihood Transformation Capacity

Expanding upon the assessment of livelihood capital stock, this study proceeds to delve into the divergences in livelihood transformation capacity across various types of forestry community households, specifically focusing on the efficacy of converting livelihood capital stock into income and expenditure levels. By employing Formula (4), the analysis reveals that the income livelihood transformation capacity of forest worker households exhibits an overall ascending trajectory, albeit trailing behind that of non-forest worker households (illustrated in the left panel of Figure 4). ANOVA results indicate significant differences among different types of forestry community households in terms of income livelihood transformation capacity (significant at the 1% and 5% levels). Notably, double-forest-worker households evidence the lowest income livelihood transformation capacity (averaging 9.349 annually), characterized by a gradual growth rate (with a 24.077% increase). The Bonferroni-adjusted significance of the difference further supports the aforementioned results. While the ability of forest worker households to convert livelihood capital stock into income levels is steadily advancing, it still remains comparatively low relative to that of non-forest worker households.

By applying Formula (5), it is determined that the consumption livelihood transformation capacity of forest worker households exhibits a general upward trend, albeit remaining inferior to that of non-forest worker households (illustrated in the right panel of Figure 4). ANOVA results indicate significant differences among different types of forestry community households in terms of consumption livelihood transformation capacity (significant at the 1% level). Specifically, double-forest-worker households display the lowest consumption livelihood transformation capacity (with an annual mean of 8.365), characterized by a modest growth rate (19.485% increase). The Bonferroni-adjusted significance of the difference further supports the aforementioned results. Although the ability of forest worker households to convert livelihood capital stock into consumption levels is steadily increasing, it still lags behind that of non-forest worker households.

Drawing from the comprehensive evaluation of livelihood capital stock and livelihood transformation capacity, this study reveals a noteworthy phenomenon: within the NSFR, distinct inter-group differentials are evident among various types of forestry community households, even manifesting entirely divergent ranking patterns in both capital stock outcomes and transformation capacity results. In contrast to non-forest worker households, forest worker households demonstrate elevated levels of livelihood capital stock but concurrently exhibit diminished livelihood transformation capacity. This observation suggests that a sole focus on the magnitude of livelihood capital stock among frontline participants in the NFPP, while disregarding their efficacy in converting it into income or consumption, may inadvertently lead to an overestimation of the sustainable livelihood levels of the study subjects.

4.3. Internal Differentiation Results of Forest Worker Households

Grounded in social stratification theory and contextualized within the realities of NSFR, this study assesses the inter-group differentials in the livelihood capital stock index among forest worker households across various stratification criteria, employing geographic stratification and seniority stratification (refer to

Table 2. Measurement results of internal differentiation in livelihood capital stock among forest worker households.

Grouping Criteria		2017		2018		2019		2020		2021
		Mean	Freq	Mean	Freq	Mean	Freq	Mean	Freq	Mean	Freq
		(Std. dev.)		(Std. dev.)		(Std. dev.)		(Std. dev.)		(Std. dev.)
Geographical Stratification	Forest farm communities on the mountain	0.264	448	0.255	431	0.260	362	0.267	329	0.282	326
		(0.082)		(0.085)		(0.080)		(0.081)		(0.089)
	Urban communities down the hill	0.260	976	0.252	1167	0.262	1322	0.281	1140	0.284	1057
		(0.072)		(0.072)		(0.072)		(0.075)		(0.072)
	Sum of Squares Between	F = 0.68		F = 0.54		F = 0.30		F = 9.11		F = 0.28
		p-value = 0.4094		p-value = 0.4644		p-value = 0.5845		p-value = 0.0026 ***		p-value = 0.6000
	Bonferroni multiple-comparison test	p-value = 0.409		p-value = 0.464		p-value = 0.585		p-value = 0.003 ***		p-value = 0.600
Seniority Stratification	Pre-1998	0.253	952	0.244	985	0.255	992	0.267	854	0.272	771
		(0.074)		(0.076)		(0.074)		(0.075)		(0.078)
	Post-1998	0.278	472	0.266	613	0.271	692	0.293	615	0.299	612
		(0.074)		(0.074)		(0.072)		(0.077)		(0.072)
	Sum of Squares Between	F = 37.83		F = 30.74		F = 20.69		F = 41.53		F = 42.80
		p-value = 0.0000 ***		p-value = 0.0000 ***		p-value = 0.0000 ***		p-value = 0.0000 ***		p-value = 0.0000 ***
	Bonferroni multiple-comparison test	p-value = 0.000 ***		p-value = 0.000 ***		p-value = 0.000 ***		p-value = 0.000 ***		p-value = 0.000 ***

Note: *** represents statistical significance at the 1% level for the observed data in terms of p-value.

for findings). Under the geographical stratification criterion, residential disparities do not exert a significant influence on the livelihood capital stock of forest worker households. However, according to ANOVA conducted under the seniority stratification criterion, seniority variations significantly impact the livelihood capital stock of forest worker households (significant at the 1% level). Particularly, forest worker households entering employment post-1998 demonstrate a notably richer livelihood capital stock. The Bonferroni-adjusted significance of the difference further substantiates these observations.

In accordance with the stratification framework described above, this research proceeds to compute inter-group differentials in livelihood transformation capacity indices among forest worker households, employing the specified criteria of geographical and seniority stratification. The outcomes of these computations are documented in

Table 3. Measurement results of internal differentiation in livelihood transformation capacity among forest worker households.

Grouping Criteria		2017		2018		2019		2020		2021
		ILTC	CLTC	ILTC	CLTC	ILTC	CLTC	ILTC	CLTC	ILTC	CLTC
Geographical Stratification	Forest farm communities on the mountain	8.192	7.766	10.606	9.321	10.859	9.605	10.891	9.813	11.122	9.891
		(4.063)	(5.165)	(5.174)	(6.794)	(5.474)	(6.935)	(4.775)	(6.202)	(5.317)	(6.561)
	Urban communities down the hill	8.582	8.601	10.511	9.445	10.991	10.477	10.972	10.436	11.096	10.294
		(4.080)	(5.243)	(5.475)	(6.129)	(5.793)	(8.376)	(8.125)	(8.560)	(4.839)	(5.797)
	Sum of Squares Between	F = 2.82	F = 7.86	F = 0.10	F = 0.12	F = 0.15	F = 3.30	F = 0.03	F = 1.51	F = 0.01	F = 1.13
		p-value = 0.0931 *	p-value = 0.0051 ***	p-value = 0.7550	p-value = 0.7283	p-value = 0.6971	p-value = 0.0694 *	p-value = 0.8641	p-value = 0.2189	p-value = 0.9327	p-value = 0.2888
	Bonferroni multiple-comparison test	p-value = 0.093 *	p-value = 0.005 ***	p-value = 0.755	p-value = 0.728	p-value = 0.697	p-value = 0.069 *	p-value = 0.864	p-value = 0.219	p-value = 0.933	p-value = 0.289
Seniority Stratification	Pre-1998	8.738	8.347	10.983	9.447	11.672	10.090	11.687	10.199	11.844	10.106
		(4.255)	(4.987)	(5.589)	(6.093)	(5.644)	(5.978)	(5.127)	(5.792)	(5.332)	(5.559)
	Post-1998	7.899	8.320	9.820	9.355	9.944	10.575	9.935	10.431	10.167	10.316
		(3.633)	(5.699)	(4.987)	(6.657)	(5.690)	(10.401)	(9.815)	(10.488)	(4.254)	(6.487)
	Sum of Squares Between	F = 13.48	F = 0.01	F = 17.77	F = 0.08	F = 37.96	F = 1.46	F = 19.73	F = 0.29	F = 40.25	F = 0.42
		p-value = 0.0003 ***	p-value = 0.9280	p-value = 0.0000 ***	p-value = 0.7789	p-value = 0.0000 ***	p-value = 0.2265	p-value = 0.0000 ***	p-value = 0.5880	p-value = 0.0000 ***	p-value = 0.5186
	Bonferroni multiple-comparison test	p-value = 0.000 ***	p-value = 0.928	p-value = 0.000 ***	p-value = 0.779	p-value = 0.000 ***	p-value = 0.227	p-value = 0.000 ***	p-value = 0.588	p-value = 0.000 ***	p-value = 0.519

Note: ILTC represents the income livelihood transformation capacity and CLTC represents the consumption livelihood transformation capacity. The statistical values in the table represent the mean values of livelihood transformation capacity of forest worker households under different stratification criteria. “( )” corresponds to the Std. dev. * represents statistical significance at the 10% level for the observed data in terms of p-value, while *** represents statistical significance at the 1% level for the observed data in terms of p-value.

.

Under the geographical stratification criterion, residential differences do not exert a significant influence on the livelihood transformation capacity of forest worker households. However, according to ANOVA results obtained under the seniority stratification criterion, variations in seniority significantly impact the income livelihood transformation capacity of forest worker households (significant at the 1% level). Notably, forest worker households who commenced employment pre-1998 exhibit a stronger capacity for income livelihood transformation. The Bonferroni-adjusted significance of the difference further substantiates these findings. This phenomenon can potentially be attributed to the predominant wage-based income structure prevalent within forest worker households, where wage-based income constitutes an average annual percentage of 78.732%. (Based on a longitudinal micro-level family survey spanning from 2017 to 2021, the analysis reveals that the share of wage income in forest worker households was 77.314% in 2017, 73.572% in 2018, 79.737% in 2019, 81.497% in 2020, and 81.541% in 2021. Consequently, the average annual share of wage income in forest worker households over this five-year period stands at 78.732%). Furthermore, households with pre-1998 employment initiation likely possess greater seniority, resulting in higher wage standards, and consequently attain elevated levels of wage-based income.

In conclusion, within the framework of seniority stratification, forest worker households display characteristic internal differentiation in their sustainable livelihood levels. Specifically, households with employment initiation post-1998 exhibit ample livelihood capital stock, whereas those with employment initiation pre-1998 demonstrate a pronounced capacity for income livelihood transformation.

5. Discussion and Conclusions

5.1. Discussion

5.1.1. Focusing on the Livelihood Issues of Frontline Participants in the NFPP: Forest Worker Households

As a large-scale natural forest conservation initiative spearheaded by the Chinese government, the livelihood concerns of participants within the NFPP are paramount for ensuring the program’s sustainability and efficacy. However, the existing literature often fails to differentiate and assess the overall welfare levels of forestry community households within the NSFR [50], potentially resulting in the marginalization of frontline participants and the overestimation of their welfare status. Forest worker households, as frontline participants in the NFPP, exemplify the theoretical concept of “forest dependency”, wherein individuals rely on forest resources for their sustenance [51]. Notably, during the NFPP implementation period, the manifestation of forest dependency has evolved: forest worker households have transitioned from a traditional forest dependency model, which primarily involved direct reliance on forest products such as timber, firewood, and forest foods for basic livelihood needs, to a “new forest dependency” model characterized by their utilization of protected and restored natural forest resources to access employment opportunities and income sources. By prioritizing the welfare and rights of frontline participants in the NFPP (forest worker households) and enhancing their sustainable livelihood levels, this approach not only upholds principles of environmental justice [52] but also addresses scholarly discourse surrounding the heterogeneous distribution of welfare effects within forest policy contexts [53,54].

The research findings suggest that forest worker households, serving as frontline participants in the NFPP, exhibit comparatively elevated levels of livelihood capital stock, yet demonstrate the poorest livelihood transformation capacity. This underscores the partiality inherent feature in the welfare measurement paradigm that aggregates forestry community households as a singular entity [55,56]. Such an approach risks inflating welfare assessments and exacerbating the marginalization of forest worker households as a relatively vulnerable group. Therefore, focusing on the livelihood issues of frontline participants in the NFPP (forest worker households) is a prerequisite for ensuring the effectiveness and sustainability of various forest protection programs.

5.1.2. Concurrent Discussion on Livelihood Capital Stock and Livelihood Transformation Capacity as Intrinsic to Assessing Sustainable Livelihood Levels

The assessment of sustainable livelihood levels within forestry community households serves as the foundational step in evaluating the effectiveness of the NFPP [57]. This assessment relies upon a well-established theoretical framework and methodological system, supported by robust research foundations. However, the implementation of the NFPP has led to divergent trajectories in the sustainable livelihood levels of forestry community households, accompanied by heightened complexity in regional livelihood contexts, thus highlighting inherent limitations in the conventional SLA. To address these limitations, this study introduces a novel technical metric, termed livelihood transformation capacity, which expands the conceptual and methodological framework of sustainable livelihood level assessment while mitigating the constraints associated with a singular emphasis on stock-based analysis. This study adheres to the conventional SLA by employing livelihood capital stock to quantify the “quantity” aspect of sustainable livelihood levels [58]. Concurrently, drawing upon Sen’s capability approach, it assesses the conversion of livelihood capital stock into income and consumption capacities, thereby utilizing livelihood transformation capacity to capture the “quality” dimension of sustainable livelihood levels.

This approach, which integrates dual perspectives, signifies an organic amalgamation of the extant literature concerning the paradigms of livelihood, income, and consumption measurement within forestry community households situated in the NSFR [59,60,61]. The research findings underscore that forest worker households, relative to non-forest worker households, exhibit heightened levels of livelihood capital stock yet encounter challenges in effectually translating it into income or consumption. On the one hand, the observed elevation in livelihood capital stock among forest worker households aligns with Lin et al.’s (2021) findings [62], elucidating that engagement in forestry-related production and operational endeavors contributes to the accrual of greater livelihood capital stock for households predominantly reliant on wage-based income [63,64]. On the other hand, the diminished livelihood transformation capacity among forest worker households furnishes a substantial complement to existing scholarship. This innovative technical metric not only encapsulates the prevalent understanding of low-income and consumption levels among forest worker households [65,66,67] but also unveils the paucity of avenues for frontline participants to convert resources into income or consumption, thereby extending the research ambit of the extant literature on the disparities in wealth [68] and welfare inequality [69] among frontline participants. Evidently, frontline participants, particularly forest worker households actively engaged in natural forest conservation and restoration efforts during the NFPP implementation, have not maximally benefitted from the welfare implications of conservation policies.

5.1.3. The Importance of Paying Attention to Social Stratification Phenomena within Forest Protection Areas

The implementation of the NFPP has profoundly influenced the sustainable livelihood levels of forestry community households, necessitating their adaptation to external policy shifts from “exploitation” to “protection”, consequently engendering discernible social stratification dynamics. Prior investigations have predominantly concentrated on the heterogeneity in the distribution of welfare effects, emphasizing the challenges in achieving equitable welfare distribution among cohorts [53,54]. However, discourse concerning the heterogeneity in welfare effects distribution within the ambit of the NFPP has been notably scant. Recent inquiries by Cao et al. (2023) have delved into the disparate allocation of NFPP welfare effects among elite groups and vulnerable groups [70], empirically substantiating the susceptibility of local elites to appropriating NFPP welfare benefits. This study extends these analyses by scrutinizing disparities in sustainable livelihood levels between frontline participants in the NFPP (forest worker households) and other participants (non-forest worker households) from the perspective of occupational stratification. Moreover, it delves into internal differentiation phenomena within forest worker households from the geographical and seniority stratification perspectives. By endeavoring to supplant poverty theory with social stratification theory, this study examines the internal differentiation challenges experienced by forest protection program participants, thereby broadening the definition of categories of vulnerable groups in forestry communities to encompass income-deprived groups [71] or materially impoverished groups [72]. Furthermore, it offers novel perspectives on the heterogeneous distribution of welfare effects within forest protection programs.

5.2. Conclusions

The NFPP, as a prominent forest protection program led by the Chinese government, holds considerable relevance as a model for guiding the formulation and enhancement of forest protection programs in other developing nations. The principal focus of this study is to estimate the dimensions and dynamics of livelihood capital stock and livelihood transformation capacity within forestry community households, predicated upon accurate identification of frontline participants in the NFPP. Additionally, it aims to explore the internal differentiation phenomena among frontline participants in the NFPP. Drawing on longitudinal household data collected from the “Livelihood Monitoring in northeast and inner Mongolia state-owned forest region” survey project spanning from 2017 to 2021, the primary empirical findings of this study are outlined below:

Initially, forest workers engaged in direct tasks such as forest management, tending, and afforestation stand as the frontline participants in the NFPP, in contrast to auxiliary roles like managers, technicians, and service personnel. Further delineating within the NSFR context, forestry community households can be categorized into forest worker households and non-forest worker households, with the former constituting the genuine frontline participants in the NFPP. It is advised that NFPP decision-makers direct significant attention toward the disadvantaged status of forest worker households concerning sustainable livelihoods, with the aim of substantiating the efficacy and sustainability of NFPP.

Moreover, forest worker households, when compared to non-forest worker households, demonstrate higher levels of livelihood capital stock but lower levels of livelihood transformation capacity. Despite possessing substantial human capital, specialized skills, and forestry production experience, forest workers encounter limitations in accessing additional income avenues and salary incentives in conservation-oriented roles, resulting in challenges related to low income and consumption. It is advisable for NFPP policymakers to integrate income incentives and stimulate consumption mechanisms into forest conservation strategies. For instance, leveraging the advantages of state-owned forest region and enhancing support for non-timber and underforest economic employment could activate the inherent drive for survival and development among forest worker households. This strategic approach would guide the elevation of the consumption structure of forest worker households, thereby mitigating the existing discrepancy between their livelihood capital stock and livelihood transformation capacity.

Ultimately, there persists a noticeable internal group differentiation phenomenon within forest worker households. The implementation of the NFPP has instigated a systematic restructuring and alteration of the socio-economic ecological system within the NSFR. A primary manifestation of this transformation is the strategic shift in human activities concerning the utilization of natural forest resources, transitioning from exploitation-oriented to conservation-focused approaches. Forest worker households exhibit characteristic seniority stratification phenomena. It is advisable for NFPP decision-makers to focus on the income levels and consumption demands of the younger demographic within the NSFR, with the aim of reducing income disparities and expanding the consumption market scope.