Does the Perceived Effectiveness of Voluntary Conservation Programs Affect Household Adoption of Sustainable Landscaping Practices?

Abstract

State and local governments have implemented voluntary and mandatory programs to conserve and protect natural resources in and around urban developments. Even though the long-term environmental benefits are apparent, convincing homeowners to adopt sustainable landscapes with less water and chemical use is challenging. An important consideration from the successful policy implementation point of view is that homeowners have different environmental attitudes, which can be the determining factor that influences their adoption intentions of sustainable landscaping practices. This study assesses whether homeowners’ environmental attitude is a statistically significant predictor of sustainable landscape adoption intention. Moreover, homeowners’ perception of the effectiveness of the voluntary environmental programs may be influenced by their environmental attitudes and impose mediating effects on sustainable landscape adoption intentions. We also examine whether homeowners’ perceived effectiveness of voluntary environmental programs has a mediating effect on the adoption decision. The Value-Belief-Norm hierarchical model framework is utilized to examine both effects. The results revealed that homeowners’ pro-environmental attitudes influence their perceived effectiveness of voluntary programs and their sustainable landscape adoption intentions. The combined influence accounts for 13.6% of homeowners’ adoption intention. Homeowners’ personal norms also affect their perceived effectiveness of voluntary programs (9% variance explained), and the mediating effect of the perceived effectiveness of voluntary programs has an amplifying effect and positively influences the adoption intention. The implications for policymakers in the realm of landscape conservation programs are discussed.

1. Introduction

The role of residential landscapes in housing market decisions has increasingly gained significance in recent decades [1]. Traditionally, monoculture turfgrass covers the majority of the landscapes, with only small landscape areas allocated to other plants, shrubs, flowers, and trees [2]. On the one hand, traditional turfgrass lawns offer many benefits, ranging from aesthetic to psychological and environmental contributions [3]. Particularly, psychological benefits brought by landscapes have been prioritized by homeowners since the outbreak of the Covid pandemic [4]. On the other hand, prevalent inappropriate landscaping practices such as excess irrigation and nutrient application may directly or indirectly cause environmental and economic damages through fertilizer (chemical) runoff or resource waste (water, fertilizer, herbicide, pesticide, labor, time), and pollute water bodies [2]. Given the current pace of urban developments fueled by the steady population growth, urban landscaping practices have become a pressing topic regarding water quality and quality conservation issues [2].

According to the previous literature, sustainable residential landscapes use partial turfgrass and non-turfgrass areas to minimize irrigation water consumption [5,6]. Incorporating such landscape designs allows for minimizing the need for water and chemical inputs while simultaneously promoting water conservation, biodiversity preservation, and the overall long-term sustainability of the environment [7]. Consequently, local governments and water management districts have worked to promote sustainable residential landscapes and practices [8].

1.1. Mandatory or Voluntary Policy

State and local governments play an active role in improving conditions for long-term environmental sustainability for future generations [9]. In order to determine the current and future conditions of the environment, governments develop regulations and conservation initiatives at different levels to maintain water and environmental sustainability. In terms of water and landscape conservation, state and local government and water management districts promote sustainable landscaping practices. Resulting regulations are often in the form of mandatory activities that are required to be carried out, but regulatory stakeholders also encourage a more proactive approach involving voluntary activities that are optional [10].

Mandatory policies play a crucial role in residential landscape conservation by providing clear guidelines for non-experts, such as homeowners, and legal frameworks for environmental protection [11]. They establish minimum standards and ensure that conservation measures are followed consistently. For instance, rules about irrigation and fertilizer applications are mandatory regulations. These policies regulate landscape practices by clearly defining the types of plants that can be used, limitations on the size of lawns, requirements for efficient irrigation systems, or the use of rainwater reclamation techniques. The effectiveness of mandatory policies relies on key elements such as enforcement and compliance monitoring, which necessitate government agencies or regulatory bodies to oversee and ensure adherence to these regulations by homeowners.

In residential landscape conservation, the significance of voluntary programs lies in their ability to promote non-mandatory or incentive-based approaches, encouraging homeowners to adopt sustainable and environmentally friendly landscaping practices. These voluntary policies rely on active participation in conservation programs and offer various incentives to motivate individuals toward positive actions and behaviors [12,13,14], 2021. For example, voluntary policies may provide tangible benefits to homeowners who choose to adopt sustainable landscaping practices, thereby incentivizing their participation. These incentives can take the form of financial incentives, such as rebates, grants, tax credits, or other monetary policies for installing water-efficient irrigation systems, native plantings, or environmentally friendly landscape designs [8].

Voluntary policies are founded on the premise that homeowners can make a positive impact on the environment by acknowledging that even small individual actions may contribute to the preservation and improvement of the overall ecosystem over time. However, it is essential to mention that while voluntary policies can effectively engage homeowners by providing education and incentives, they may not guarantee improvements in homeowners’ environmental attitudes, pro-environmental behavior, and the effectiveness of different policies [15].

1.2. Objectives

Even though the benefits of sustainable landscapes are apparent in terms of extrinsic factors, it is essential to recognize that other factors also play a significant role in achieving successful pro-environmental outcomes. To gain a comprehensive understanding, it is crucial to understand homeowners’ perspectives in the context of residential landscaping practices and their associated challenges. In residential landscaping practices, it is critical to consider homeowners’ intrinsic factors when attempting to persuade them to adopt sustainable landscaping practices and transform from fully turfgrass lawns to more sustainable landscapes [16]. Failing to account for these factors can pose challenges in effectively promoting and implementing sustainable landscaping practices.

Homeowners’ attitudes and perceptions towards the environment may influence homeowners’ pro-environmental behavior and intention [9,13,16,17,18]. Moreover, homeowners’ knowledge, skills, experience, perceptions, value orientations, environmental beliefs, considerations of social norms, and a range of economic relations may influence the effective promotion of the adoption of sustainable landscapes [16,17,18].

Previous studies investigated the relationship between attitudinal or perceptional factors and behaviors in landscape conservation practices. For example, Suh et al. [18] identified that external factors and characteristics of the household may affect environmentally friendly behaviors. Another recent study reported that homeowners’ landscape maintenance-related perceptions, knowledge, environmental attitudes, and consideration of future consequences might influence their pro-environmental behavior [19]. Zhang et al. [16] found that Floridian homeowners’ perceptions of landscape practices (i.e., being more agreeable with the positive consequences of sustainable landscape practices) positively affect sustainable landscape adoption.

Both mandatory and voluntary approaches have been deliberated, approved, and implemented by local legislators (policymakers) or developed by the water management districts, demonstrating their potential to engage homeowners. However, it is essential to note that while imposing regulations may yield more immediate results, it may not necessarily lead to the proper or desired use of the practice.

In this study, our focus is not on the direct assessment of the effectiveness of conservation programs. Instead, we aim to explore the impact of homeowners’ perceived effectiveness of such programs on their pro-environmental behaviors. Suppose the households are aware of mandatory and voluntary programs or have personal experience with them. In that case, it is likely that they may have acquired knowledge and developed a perception regarding their effectiveness (perceived effectiveness). In addition to awareness and knowledge, understanding the impacts of the perceivedeffectiveness on homeowners’ intention to adopt these programs is crucial for gaining a comprehensive understanding of the barriers and motivations associated with their adoption.

Investigating and presenting the implications for policymakers is of significant value in guiding informed decision-making. It is particularly true in the case of sustainable landscape programs, as voluntary initiatives often require substantial economic incentives. Therefore, if positive perception plays a role in driving higher adoption intentions, emphasizing improving individual perceptions (rather than solely increasing incentives) and improving environmental attitudes could help achieve more effective outcomes for landscape conservation programs.

Drawing upon the preceding arguments, it is evident that homeowners’ motivational factors play a pivotal role in shaping pro-environmental behavior [9,16,17,18,19]. Homeowners’ perceptions of the effectiveness of the programs may also affect their environment-related decisions as a mediator (but not vice versa). If they perceive voluntary actions effectively addressing the environmental issue, they may be more likely to participate in the program and change pro-environmental behavior. However, limited studies have been undertaken to combine homeowners’ motivational factors with their knowledge and perception of conservation programs to understand their pro-environmental behaviors and specific decisions regarding sustainable landscape adoption. It is unclear whether homeowners’ environmental attitudes affect their sustainable landscape adoption. It is also unclear whether homeowners’ perceived effectiveness of the programs affects their pro-environmental intention. Finally, it is also unclear whether the attitudes toward the environment affect the perceived effectiveness of voluntary landscape conservation programs.

In the relationships mentioned above, the Value-Belief-Norm (VBN) hierarchical model developed by Stern et al. [20] can be extended by adding a mediating factor in the form of the perception of landscape conservation program effectiveness (voluntary or mandatory). It is worth reminding that a mediating effect refers to a mechanism or process that helps explain the relationship between the two variables (in this case, between the environmental attitudes and the pro-environmental behavior).

The objective of the present study is twofold. We aim to use the VBN framework to reveal the direct effect of homeowners’ environmental concerns on their adoption intentions of sustainable landscape alternatives. Second, we aim to reveal the potential mediating effect of homeowners’ perception of the effectiveness of voluntary landscape conservation programs on the adoption intention. We can then also explore whether and to what extent motivational factors (attitudes toward the environment) influence the perceived effectiveness of the program as well.

1.3. Hypotheses

To integrate homeowners’ attitudinal factors and program-related perceptional factors, the Value-Belief-Norm (VBN) model by Stern et al. [20] provides a suitable theoretical framework for our objectives. The VBN model has been used in many pro-environmental and pro-social behavior-related studies [17,19,21,22,23,24]. In our study, homeowners’ perceptions of the effectiveness of voluntary activities (but not of mandatory programs) are the focus since existing landscape conservation programs are mainly voluntary, and most homeowners may be able to relate to them conveniently. Another reason was due to the potential collinearity issue, where attitudes toward the environment might affect the perceived effectiveness and their pro-environmental behavior. Hence, choosing one type of program to examine may provide a reference for both types of programs.

Based on the discussion in the previous literature, we predict that in addition to the significance of the constructs of the VBN model, homeowners with greater environmental concerns will be more likely to adopt sustainable landscapes. The perception of voluntary program effectiveness has a mediating effect on the adoption decision. Homeowners with better-perceived effectiveness (due to the obligation that is imposed on themselves) will have a positive impact on adoption intention. Specifically, the following three hypotheses are tested in the present study.

H1. 

Homeowners’ motivational factors (individual values and general environmental beliefs) will positively affect the intention of sustainability landscape adoption.

H2. 

Homeowners’ perceived effectiveness of voluntary programs significantly mediates the relationship between personal norms (attitudes toward the environment) and pro-environmental outcomes. Homeowners’ perceived effectiveness of voluntary programs will positively influence their pro-environmental behavioral intention and the adoption intention of sustainable landscapes.

H3. 

Homeowners’ environmental attitudes (through personal norms) will positively influence their perceived effectiveness of voluntary landscape conservation programs.

To test our hypotheses, we collected data from residents in Florida. The state has leading efforts in water conservation and landscape transformation programs. Implications can be used to reinforce educational and voluntary landscape conservation programs at the regulatory level, as well as for educators engaged in designing and delivering urban landscape conservation programs.

2. Materials and Methods

2.1. Theoretical Framework

The value-belief-norm (VBN) model offers a relevant theoretical foundation for this study. The VBN theory developed by Stern et al. [20], assumes a hierarchical construct where individuals’ pro-environmental behavior is shaped by their personal values, the beliefs they hold about the environment, and the norms or societal expectations related to environmental responsibility [17,21,22,23,24].

The VBN model is comprised of a total of seven factors. Individuals’ value orientations include biospheric, altruistic, and egocentric measures. The general beliefs measure social awareness of the biosphere, which is the new environmental paradigm (NEP). The individual’s recognition of the potential consequences of people’s actions on the environment is incorporated by the awareness of consequences (AC) construct. The belief in acceptance of responsibility to self is entered into the model through the ascription of responsibility (AR) construct. The last factor is the sense of moral obligation towards the environment, i.e., the personal norms (PN) construct. The activation of personal norms for actions directly determines homeowners’ pro-environmental behaviors [17,19,21,22,23].

This study used the VBN model to predict homeowners’ adoption intention of sustainable landscapes, Florida-friendly landscape (FFL). In addition, we added the additional variable (i.e., perceived effectiveness) between the personal norms and the adoption decisions to examine the potential mediating effect. The perceived effectiveness of voluntary programs (PE) is hypothesized to have a mediating effect between the PNs and the FFL adoption intention (FFL). The extended VBN model is shown in Figure 1.

The first level includes values that consist of biospheric, social or altruistic, and egocentric or selfish orientations. The value orientations affect the second level, the beliefs about the environment and the relationships with nature (new environmental paradigm), the profound awareness of the consequences of their behavior toward the environment, and the acceptance of responsibility to self. Finally, on the third level are attitude, a sense of moral obligation towards the environment, and personal norms, which determine actions. In the VBN model, the last variable (personal norm) directly determines pro-environmental behavior, and all other variables have indirect effects through personal norms. The activation of a personal norm for actions directly determines homeowners’ pro-environmental behaviors (adoption intention) [22]. The extended VBN model integrates the perception of voluntary programs to predict homeowners’ sustainable landscape adoption intention. It is hypothesized that homeowners’ environmental attitudes will positively influence the perceived effectiveness of voluntary programs and positively influence the intentions to adopt FFLs (Figure 1).

2.2. Survey Methods

To collect homeowners’ environmental attitudes and perceptions toward landscape-related regulations, an online survey was arranged in Florida using the Qualtrics survey platform in June 2022. The online survey was part of a broader study of homeowners’ preferences for sustainable landscape practices and turfgrass attributes. The survey was approved by the Institutional Review Board of the university (protocol IRB201903168).

There were five sections in the survey. The Section 1 ensured that only homeowners who engage in landscape practices were included in the survey. The Section 2 asked questions about homeowners’ understanding of turfgrass and preferences and perceptions of landscapes. The Section 3 was a set of choice experiment questions for turfgrass lawns (which was not included in this study). The Section 4 consisted of questions about participants’ value orientation, environmental-related beliefs, and personal norms. The Appendix A included socio-demographic questions.

The Qualtrics platform sent invitations to its panel respondents in Florida. In our study, we collected a total of 3833 responses. The final valid responses used in this study is 650 (with a 17% completion rate). The sample socio-demographic information is shown in

Table 1. Sample statistics of socio-demographics.

	Survey Sample	FL Census Group b
Number of Responses	650	-
Age	51.4 a	42.8
Female (%)	58.9	50.8
Caucasian	82.9	57.7
African American	6.5	15.1
Hispanic	4.8	26.5
Other ethnicities	5.8	3.4
Education (%)
High school degree	12.2	27.7
College degree	67.5	49.5
Graduate degree	17.3	12.6
Employed full-time (%)	43.2	55.4
Income (%)
Less than $10,000	3.0	6.3
$10,000–$49,999	37.9	33.4
$50,000–$99,999	33.0	31.1
$100,000 above	26.1	29.3

a. The survey sample does not include people younger than 18 years old. b. Data from the U.S. Census Bureau [25].

. Participant demographics revealed that approximately 59% were female (Table 1). The average age of participants was 51.4 years. In terms of ethnic makeup, 83% of the participants identified themselves as Caucasian, while 6.5% identified as African American and 4.8% as Hispanic. Moreover, a significant majority of respondents, approximately 83%, had completed education beyond the college level. In terms of employment, about 43% of participants were currently engaged in full-time jobs. When examining annual household income levels, the range varied from below $19,999 to above $100,000. Notably, the most significant portion of participants (38%) fell within the income bracket of $10,000 to $49,999, while 26.1% belonged to the above $100,000 category (Table 1). It is worth noting that our sample’s characteristics deviated from that of the general population of Florida, as reported by the U.S. Census. The variation can be attributed to how we screened our participants, ensuring that they either lived in a detached house and took care of their own lawn/garden or hired professional landscaping services. However, it is still possible that the sample was under-representative for specific ethnic groups, such as African American and Hispanic homeowners. This issue needs to be taken into consideration in the follow-up research for sustainable landscapes.

For the environmental attitude-related questions, the scales were adapted. Specifically, the three value orientations were directly adapted from Stern et al., 1999 [20]. The New Ecological Paradigm measuring participants’ attitudes toward the environment was revised based on the scale from Dunlap et al. [26] and Fielding et al. [27].

Except for the value orientations, measured on a 7-point Likert scale, all other scales were measured on the 5-point Likert scale (for attitudes and beliefs regarding environmental conservation). The means, standard deviations, average inter-item correlations, and Cronbach’s alpha of the items are summarized in

Table 2. Descriptive summary of the environmental-related scale questions and the confirmatory factor analysis.

Constructs	Mean	Std. Dev.	Average Inter-item Correlations	Alpha
Biospheric, Egoistic, and Altruistic values [20]
Biospheric values
Preventing pollution (Conserving natural resources)	5.47	1.20	0.52	0.81
2. Respecting the Earth (Harmony with other species)	5.76	1.19	0.48	0.79
3. Unity with Nature (Fitting into nature)	5.48	1.27	0.47	0.78
4. Protecting the Environment (Preserving nature)	5.66	1.22	0.46	0.77
5. Influential (Having an impact on people and events)	4.60	1.49	0.64	0.87
			0.52	0.84
Egoistic values
6. Social Power (Control over others, Dominance)	3.30	1.74	0.26	0.58
7. Wealth (Material possessions, Money)	3.60	1.72	0.26	0.58
8. Authority (The right to lead or command)	3.69	1.73	0.23	0.55
9. Equality (Equal opportunity for all)	5.51	1.42	0.35	0.69
10. A World at Peace (Free of war/conflict)	5.65	1.45	0.37	0.70
			0.29	0.68
Altruistic values
11. Social Justice (Correcting injustice, caring for the weak)	5.20	1.67	0.60	0.82
12. Helpful (Helping others)	5.87	1.21	0.46	0.72
13. Loyalty (Faithful to my friends)	6.11	1.09	0.46	0.72
14. Honoring Parents and Elders (Showing respect)	6.16	1.11	0.53	0.77
			0.51	0.81
New Ecological Paradigm [26,27]
When humans interfere with nature, the consequences can be disastrous	4.08	0.88	0.35	0.81
2. Plants and animals have as much right to live as humans	4.17	0.93	0.36	0.82
3. Humans are seriously abusing the environment	4.11	0.97	0.33	0.79
4. The balance of nature is very delicate and easily upset	4.10	0.87	0.34	0.80
5. We are in for a major environmental catastrophe	3.70	1.14	0.33	0.80
6. We are approaching the maximum number of people the earth can support	3.30	1.14	0.35	0.81
7. The Earth is like a spacecraft with limited resources	3.69	1.05	0.34	0.80
8. Humans are still subject to the laws of nature	4.21	0.76	0.37	0.82
9. The earth has plenty of natural resources if we just learn how to develop them	3.80	1.02	0.45	0.87
			0.36	0.83
General Awareness of Consequences [17,28]
Protection of the environment benefits us all	4.42	0.79	0.53	0.89
2. In the next decade, thousands of species will become extinct	3.60	1.03	0.56	0.90
3. What they say about climate change is an exaggeration	2.44	1.36	0.55	0.89
4. Environmental threats to public health are exaggerated	2.45	1.30	0.51	0.89
5. Environmental protection is beneficial for my health	4.16	0.87	0.50	0.88
6. Environmental protection means a better world	4.24	0.91	0.50	0.87
7. Environmental protection improves my quality of life	4.15	0.92	0.50	0.88
8. The environmental damage we cause here affects people	4.17	0.93	0.52	0.88
			0.53	0.90
Ascription of Responsibility [17]
Every member of the public should accept responsibility	4.29	0.78	0.08	-
2. The authorities are responsible for the landscape conservation	3.08	1.07	0.28	0.44
3. I am not worried about the environment and landscape conservation	2.24	1.23	0.17	0.29
			0.12	0.30
Personal Norm [17,29]
I feel I ought to preserve water resources and practice sustainable landscaping	4.03	0.88	0.70	0.82
2. I feel guilty when I don’t preserve water resources and practice sustainable landscaping	3.63	1.07	0.70	0.82
			0.70	0.82
Perceived Effectiveness of Voluntary/Mandatory Participation Programs
Voluntary participation in landscape conservation programs will be effective in improving water conservation efforts in the state of Florida	5.04	1.52
2. Mandatory landscape conservation policies will be effective in improving water conservation efforts in the state of Florida.	4.65	1.86
Adoption Intention for Florida-Friendly Landscape
How likely is it that you will purchase/install a Florida Friendly landscape in the next five years?	4.08	1.53

Note: Alpha: reliability (Cronbach’s alpha); Cronbach’s alpha measures the reliability or consistency of the responses to those items [30]. A higher alpha indicates greater internal consistency, suggesting that the items in the scale are strongly correlated with each other and are likely measuring the same construct.

. Participants showed strong environmental attitudes and were in favor of adopting sustainable landscapes.

In section four of the survey, we asked questions about homeowners’ perceptions regarding the effectiveness of voluntary and mandatory landscape conservation programs. The perceived effectiveness of voluntary participation is included in the SEM model as the mediating factor. The question asked is, “Please indicate your agreement with the following statement: Voluntary participation in landscape conservation programs will be effective in improving water conservation efforts in the state of Florida.” The 7-Likert scale question collected the participants’ perceived effectiveness of both programs. The results from the survey responses are also summarized in Table 2. On average, the participants have a value of 5.04 for the perceived effectiveness of voluntary participation (greater than 4.65 for the perceived effectiveness of mandatory participation). The descriptive result implies that homeowners perceived voluntary programs as more effective than mandatory programs.

2.3. The Structural Equation Model

The Structural Equation Model (SEM) can be used to analyze the relationship between the unobserved latent variables and the observed variables, model a system with many endogenous variables and correlated errors, and estimate mediation effects. In this study, SEM was used to reveal the effects of homeowners’ environmental attitudes and the perceived effectiveness of voluntary programs on their FFL adoption intention. SEM is commonly used to analyze the structural correlation between interconnected factors, given its ability to reveal multiple correlations in a path diagram [9,17,21,24].

Figure 2 depicts the SEM model. Circles contain latent variables (Value, Belief, and Norm in this study). As shown in the figure, the key parameters are the ηs. Boxes contain observable variables. Except Y1 and Y2 are the observed dependent variables for homeowners’ Perceived Effectiveness of Voluntary Programs and FFL adoption intentions, all other Ys are the observed indicators for the latent variables. Moreover, βs and γs are the path coefficients for the estimated SEM model (reported in

Table 3. Direct and indirect effects estimated from the Structural Models (2nd Stage SEM).

Factor Relationship	Effects (β)	S.E.	R-Squared or Explained Variance
NEP ← BIO	0.59 ***	0.055	0.477
NEP ← EG	0.031	0.036
NEP ← AL	0.13 ***	0.059
AC ← NEP	0.79 ***	0.019	0.623
AR ← AC	0.97 ***	0.044	0.947
PN ← AR	0.76 ***	0.041	0.575
FFL ← PN	0.28 ***	0.041	0.136
FFL ← PE	0.17 ***	0.039
PE ← PN	0.30 ***	0.039	0.090

Note: Value Orientation includes BIO (Biospheric), EG (Egoistic), and AL (Altruistic). Beliefs include NEP (New Ecological Paradigm), AC (Awareness of consequences), and AR (Ascription of Responsibility). Personal Norm (PN). Homeowners’ sustainable landscape adoption intention (FFL). PE stands for homeowner perceived effectiveness of voluntary programs (PE). *** indicates 1% significance levels.

). The λs are the coefficients estimated by the confirmatory factor analysis (first stage SEM) (reported in Appendix A). The εs and δs are the error terms connected to the constructs and observed variables.

The SEM command for conducting SEM in Stata 13.0 was applied in the analyses. We followed the two-step approach [31]. The Confirmatory Factor Analysis (CFA) was first used to ensure that items in the same construct are highly correlated with each other. Our results showed that individual values and environmental attitudes adequately measure the relationships between the observed variables and the underlying factors. Then, the reliability analysis was conducted using Cronbach’s alpha coefficient to assess the internal consistency of the items [30]. As the general threshold of acceptability, we confirmed that the reliability and inter-item correlation Cronbach’s alpha coefficient was higher than 0.7, and the correlation between items exceeded 0.3 (Table 2, columns 4–5).

After confirming the reliability and inter-item correlation, in the second stage, SEM was applied to test the construct’s relationships in the VBN model. The goodness of fit (GoF) on the model level and the equation level (EQGoF) were both tested. The GoF statistics for the constructs include chi-square (Chi2), comparative fit index (CFI), and robustness of mean squared error approximation (RMSEA). The results will be discussed in the next section.

We expected that homeowners’ perceived effectiveness of voluntary programs has a mediating effect between environmental attitude and adoption intention in the VBN model. More specifically, we expected that the correlation between the independent variables (personal norms) and the dependent variables (adoption intention) would be partially or fully explained by the inclusion of the mediating variable (perceived effectiveness). Understanding the mediating effects can provide a more comprehensive understanding of how those attitudinal factors are related and help identify the specific pathways through which they influence each other and determine the pro-environmental behaviors, such as the adoption of sustainable landscapes.

3. Result and Discussion

We summarized the responses of homeowners’ likelihood of adopting a Florida-Friendly Landscape in the next five years in Figure 3. The adoption intention (FFL) is the dependent variable with the ordered-response format using a 7-point Likert scale (extremely unlikely = 1; extremely likely = 7). More than one-third of the participants were undecided, 38% of responses ranged from likely to very likely, and 27% indicated very unlikely and somewhat unlikely). The result suggests that while the majority of homeowners remain undecided, there is a slight proportion leaning toward the likely side of the scale compared to the unlikely side. There is a promising opportunity for change in decision-making regarding alternative landscapes, as approximately 67% of homeowners have the potential to be encouraged toward adopting these practices. This finding validates the research objectives, highlighting the need to gain a deeper understanding of barriers and incentives from both motivational (attitudes) and perceptional (perceived effectiveness) perspectives. Such insights are helpful for policymakers to make informed decisions and for extension agents to implement targeted outreach educational programs.

To ensure the overall model can reflect the true structure, a measurement model fit test is conducted. The results of the measurement models are shown in the last two columns in Table 2 and Appendix A 

Table A1. Confirmatory Factor Analysis (1st stage SEM).

Constructs	Coef.	Std. Err.	Alpha
Biospheric, Egoistic, and Altruistic values (alpha)
Biospheric values (alpha)			0.84
Preventing pollution (Conserving natural resources)	0.68	0.02
2. Respecting the Earth (Harmony with other species)	0.83	0.02
3. Unity with Nature (Fitting into nature)	0.81	0.02
4. Protecting the Environment (Preserving nature)	0.86	0.01
5. Influential (Having an impact on people and events)	0.46	0.03
Egoistic values (alpha)			0.68
6. Social Power (Control over others, Dominance)	0.79	0.02
7. Wealth (Material possessions, Money)	0.78	0.02
8. Authority (The right to lead or command)	0.86	0.02
9. Equality (Equal opportunity for all)	0.74	0.02
10. A World at Peace (Free of war/conflict)	0.71	0.02
Altruistic values (alpha)			0.81
11. Social Justice (Correcting injustice, Caring for the weak)	0.72	0.02
12. Helpful (Helping others)	0.75	0.02
13. Loyalty (Faithful to my friends)	0.71	0.02
14. Honoring Parents and Elders (Showing respect)	0.60	0.03
New Ecological Paradigm (alpha)			0.83
When humans interfere with nature, the consequences can be disastrous	0.64	0.03
2. Plants and animals have as much right to live as humans	0.60	0.03
3. Humans are seriously abusing the environment	0.83	0.01
4. The balance of nature is very delicate and easily upset	0.75	0.02
5. We are in for a major environmental catastrophe	0.78	0.02
6. We are approaching the maximum number of people the earth can support	0.57	0.03
7. The Earth is like a spacecraft with limited resources	0.67	0.02
8. Humans are still subject to the laws of nature	0.57	0.03
9. The earth has plenty of natural resources if we just learn how to develop them	0.02	0.04
General Awareness of Consequences (alpha)			0.90
Protection of the environment benefits us all	0.76	0.02
2. In the next decade thousands of species will become extinct	0.57	0.03
3. What they say about climate change is an exaggeration	−0.58	0.03
4. Environmental threats to public health are exaggerated	−0.59	0.03
5. Environmental protection is beneficial for my health	0.82	0.01
6. Environmental protection means a better world	0.88	0.01
7. Environmental protection improves my quality of life	0.85	0.01
8. The environmental damage we cause here affects people	0.78	0.02
Ascription of Responsibility (alpha)			0.30
Every member of the public should accept responsibility	ns	ns
2. The authorities are responsible for the landscape conservation	0.21	0.04
3. I am not worried about the environment and landscape conservation	0.43	0.04
Personal Norm (alpha)			0.82
I feel I ought to preserve water resources and practice sustainable landscaping	0.88	0.02
2. I feel guilty when I don’t preserve water resources and practice sustainable landscaping	0.80	0.02
Chi2 = 3263.3, p < 0.000, RMSEA = 0.08, CFI = 0.80, TLI = 0.79, SRMR = 0.12

Note: Coef: standard regression weight; Alpha: reliability measure (Cronbach’s alpha); RMSEA: Root mean squared error of approximation; CFI: comparative fit index; TLI: Tucker-Lewis index.

. The confirmatory factor analysis (CFA) successfully verified the construct validity within the VBN model, encompassing seven factors of altruistic, egoistic, biospheric values, new ecological paradigm, general awareness of consequences, ascription of responsibility, and personal norms. One item from the ascription of responsibility was removed to improve reliability. After removing the item with a correlation inferior to 0.30, the scales showed reliability above 0.80 (with the exception of egoistic values). Cronbach’s alpha coefficients confirmed the internal consistency of the scale items. All standardized coefficients of the latent variables were higher than the threshold of 0.4. Except for one item in NEP, all other items were significant (p < 0.01). The statistics show that most of the parameters have passed the minimum threshold (Table A1).

Several statistics of the overall goodness of fit for the model were reported in Table A1, such as root mean square error of approximation (RMSEA), square root mean residual (SRMR), comparative fit index (CFI), and normed chi-square (Chi2) can be used for the overall model fit test. They are reported as Chi2 = 3263.3, p < 0.000, RMSEA = 0.08, CFI = 0.80, TLI = 0.79, SRMR = 0.12. The statistics showed that the overall VBN model fitted the data well.

The structural model results are illustrated in Table 3 and Figure 4. The equation level of goodness-of-fit statistics, i.e., R-squared values, are also shown in Table 3 (the fourth column). It is worth noting that in the SEM model, the percentage of the variance explained refers to the proportion of variance that can be accounted for by the model, providing an indication of how well the model explains the underlying structure.

As expected, most effects in the VBN model were significant (p < 0.01). One exception was that the egoistic value orientation showed an insignificant effect on the new ecological paradigm (β = 0.031). While the VBN model is a commonly employed model in studies related to the environment, the egoistic value does not emerge as a strong predictor of homeowners’ general environment attitude (as measured by NEP) in this case. The same insignificance has been noted in previous studies concerning the correlation between egoistic values and environmental attitudes. However, for consistency with the standardized VBN structure, the scale of the egoistic value was not omitted in this study. This approach ensures adherence to the established framework despite the lack of significance observed in relation to homeowners’ egoistic value orientation and environmental attitudes.

Figure 4 illustrates the explained proportion of variance using the VBN model.

Our results found that the biospheric, egoistic, and altruistic values combined explained 47.7% of the variance of the new environmental paradigm. The biospheric values were found to be more influential than altruistic and egoistic values (β = 0.59 vs. β = 0.13, respectively). Moreover, in the belief section, the new environmental paradigm explains 62.3% of the variance of awareness of consequences (β = 0.79). The general awareness of consequences (β = 0.97) covers 94.7% of the ascription of responsibility. The structure also has significant values between (ascription of responsibility) and personal norms (β = 0.76). The belief of ascription of responsibility explains 57.5% of the variance of personal norms) (Table 3). The last section of the construct includes a direct effect of personal norms on homeowners’ sustainable landscape adoption intention and a mediating effect on homeowners’ perception of the effectiveness of voluntary programs.

Our results demonstrate that while the R-squared value (explained variance) may not be substantial (13.6%), it remains highly significant. The results indicate that Personal Norms have a significant effect in driving individuals’ intention to adopt sustainable landscapes. The combined influence of the personal norm toward the environment and their perception of the effectiveness of voluntary programs accounts for 13.6% of homeowners’ adoption intention.

Moreover, the perceived effectiveness of voluntary programs has a truly mediating effect in predicting adoption intention. Notably, the individual’s personal norm towards the environment also positively influences their perception of effectiveness. In other words, this mediating effect of the perception can be seen as an amplifying effect, which can be improved by homeowners’ environmental attitudes. Consequently, it increases the likelihood of homeowners adopting sustainable landscapes.

Our findings are in line with previous studies [17,24]. A positive environmental attitude, characterized by environmental concerns, has an important impact on enhancing people’s belief in social awareness and responsibility. Moreover, it strengthens their conviction in the effectiveness and success of voluntary programs, ultimately fostering pro-environmental behavior.

To better illustrate the correlations for the VBN structural model, the hierarchical construct is shown in Figure 5. It confirms the hypothesis of the significant mediating effect of the perceived effectiveness of voluntary programs on sustainable landscape adoption intention.

This study revealed the direct effect of homeowners’ environmental attitudes on their intentions to adopt sustainable landscape alternatives. In addition to individual values, beliefs, and personal norms, the potential mediating effect of homeowners’ perceived effectiveness of voluntary landscape conservation programs was also examined. This study combines the intrinsic factors with the perceptional factors derived from the awareness and knowledge about landscape maintenance and conservation-related policies and programs to predict homeowners’ pro-environmental behavior.

Our results revealed significant and positive correlations in the VBN model, therefore, supporting our hypotheses. First, homeowners’ motivational factors (values, general environmental beliefs, etc.) positively affect the intention to adopt sustainable landscapes. The first hypothesis (i.e., homeowners’ motivational factors—individual values and general environmental beliefs—will positively affect the intention of sustainability landscape adoption) was fully supported. It confirmed that homeowners’ environmental attitude is a statistically significant predictor of their landscaping behavior (intention).

The second hypothesis was supported as well. Homeowners’ derived perception of the effectiveness of voluntary landscape programs showed a significant mediating effect on the adoption intention. Although it is a mediating effect through personal norm development, the results show that the mediating effect is bigger than the direct effect of the personal norms on the adoption intention. In other words, in the case of adopting a sustainable landscape, homeowners’ choice of sustainable landscape design through voluntary landscape conservation programs could be a critical route, and the perception of the effectiveness explains more for the outcomes.

Our results also supported the third hypothesis, in which we predicted that homeowners’ environmental attitudes (through personal norms) would positively influence the perceived effectiveness of voluntary landscape conservation programs. In addition, the mediating effect is more substantial than the direct effect of the personal norm on the dependent variable (the adoption intention). This is in line with our expectations. Homeowners with greater pro-environmental concerns will not only proactively take action, but they will also believe that voluntary participation with incentives can be more effective than mandatory regulations.

Our study confirmed the suitability of the VBN model as a theoretical framework for predicting homeowners’ behavior regarding the adoption of sustainable landscapes. Homeowners’ motivations for installing sustainable landscapes, such as FFL, are multifaceted. Not only are their values, environmental beliefs, and personal norms influential in their adoption intentions but also their perception of the effectiveness of voluntary programs also plays a significant role. If homeowners prioritize environmental concerns, they are more likely to perceive voluntary programs as effective and be more inclined to accept sustainable landscape alternatives.

4. Conclusions

Voluntary landscape conservation programs promote non-mandatory or incentive-based approaches and encourage homeowners to adopt sustainable and environmentally friendly landscaping practices. To improve the actual effectiveness of related policies and programs, outreach programs developed by local governments or extension agents can target the general environmental attitude, such as the NEP or overall environmental concerns. Outreach educational programs can also enhance homeowners’ perception of the effectiveness of voluntary programs for landscape conservation. Although homeowners with greater environmental concerns tend to adopt sustainable landscapes even without the mediation, reinforcing the perceived effectiveness of voluntary programs will further and substantially increase their willingness to install such landscape alternatives. Therefore, an effective strategy would involve combining general environmental education with the dissemination of encouraging information specific to landscape conservation programs.

Our study has implications for policymakers in the realm of landscape conservation programs. The influence of authority support is evident, indicating that strategies employed by policymakers to promote environmental awareness and foster a sense of responsibility are on the right track. Particularly, examining homeowners’ perceptions of landscape conservation programs can provide a valuable tool for understanding pro-environmental behavioral changes. The potential mediating effect of homeowners’ perceived effectiveness can have a greater influence than the program’s self-suggested effectiveness. Education and outreach programs, such as FFL, can influence the general environmental attitude and directly improve the effectiveness of voluntary programs by shifting pro-environmental attitudes. Policymakers can leverage homeowners’ perceived effectiveness of voluntary programs as a mediating factor to promote sustainable landscaping behaviors.

Education and outreach programs can focus on shaping homeowners’ general environmental attitudes and enhancing their awareness, knowledge, and perception (including perceived effectiveness) of landscape programs. By providing resources and information, the perception of the effectiveness of voluntary programs can be improved, further amplifying the impact on homeowners’ adoption intentions of sustainable landscaping practices. This situation will be viewed as a positive trend, indicating that all the support provided by local governments for voluntary programs is perceived as more effective. Thus, support local governments, water management districts, and extension agents to move in the right direction to achieve positive outcomes.

Overall, prioritizing the fostering of environmental awareness, shaping attitudes, and driving positive behavioral changes among homeowners should be a top priority for local authorities, water management districts, extension agents, and landscape conservation programs. Continuously supporting and enhancing these programs is critical in effectively promoting sustainable landscape practices and contributing to the overall conservation and preservation of landscapes.

Our study is not free from limitations. Due to the potential multicollinearity issue, to avoid confusion in the analysis, we did not include homeowners’ perceptions of the effectiveness of mandatory participation. Thus, it is unclear whether it has a similar positive mediating effect similar to voluntary programs. Nevertheless, the brief exploratory analysis showed that homeowners perceived mandatory programs as slightly less effective compared to voluntary programs. If the improvement of environmental concern (environment attitude) can already encourage the adoption of a sustainable landscape, mandatory programs can be applied to focus on other areas where mandatory programs are more appropriate and urgent (i.e., pollution and water body conservation) with more resources. A separate study can be conducted to address this research gap. It is important to note that while voluntary policies can be effective in engaging homeowners, they may not achieve comprehensive conservation outcomes on their own. A combination of voluntary and mandatory approaches, along with proper enforcement and monitoring, can lead to more impactful, widespread, and sustained residential landscape conservation efforts. It is worth mentioning another potential research limitation due to the under-representative racial and ethnic groups. Since the changing population combination in Florida, understanding their environmental attitudes and their perception of voluntary programs will be increasingly vital for the success of both mandatory and voluntary environmental policies.