1. Introduction
With the intensification of land resource utilization, human research on land resources, especially the development and utilization of cultivated land resources, has become increasingly deep [
1]. Land-use transition, as an important piece of content of land system science research, has become an important scientific frontier [
2,
3]. Land-use transition theory is a theoretical framework for studying land-use changes, emphasizing that, in different historical periods and different stages of socio-economic development, the patterns, structures, and methods of land use will undergo major changes, forming different stages of land-use transition [
4,
5]. Through research, Long Hualou proposed the theory of regional land-use transition patterns [
6,
7], which reveal the essence of regional land-use transitions. Long Hualou believes that land use morphology includes dominant morphology (whose change can cause explicit land-use transition) and recessive morphology (whose change can cause implicit land-use transition). Dominant morphologies are presented through the quantity and structure of land use, while recessive morphologies are special morphologies which rely on the dominant morphology, including the land use features in the aspects of quality, property rights, management mode, input, output, and function [
8]. Regional land-use transition is actually a comprehensive manifestation of the dominant and recessive morphologies of different types of land use [
9]. The transformation of land use types affects the morphology of land use and needs to be balanced through a land-use transition. Land-use transition is essentially a process of alleviating land type conflicts representing different sectoral interests by changing land use morphologies [
10].
Cultivated land-use transition is derived from the theory of land-use transition, and it can be defined as the trend change or inflection of the morphology of cultivated land use (including dominant and recessive morphologies) in a long-time series in a certain region [
11,
12]. Consequently, cultivated land-use recessive transition is the change or inflection from one recessive morphology of cultivated land use to another over a period of time, driven by economic and social change, as well as innovation, in a certain region. Currently, there have been abundant research results on the transition of cultivated land use at home and abroad [
9]. Based on different spatio-temporal scales and different research perspectives [
13,
14], combined with data analysis and field research, a variety of systematic studies have been conducted, and they obtained a large number of enlightening research conclusions and a rich method system. Most studies on the transition of cultivated land use start from the area, share, and spatial pattern changes of cultivated land [
15], focusing on the transition process of the dominant morphology of cultivated land composed of the quantity structure and spatial pattern of cultivated land [
16,
17,
18]. With the continuous enrichment of research content, research considering both the dominant and recessive morphologies of cultivated land have gradually increased. Most of them were analyses of the spatial differentiation laws of cultivated land-use transitions [
19]. Some studies built frameworks and conducted evaluation analyses from the transition of regional cultivated land–function forms [
20]. A small number of studies proposed the green transition of cultivated land use or analyzed the changes in the form of cultivated land while considering the background of regional urban and rural development stages [
21,
22,
23]. From the perspective of research areas, most of the studies were mainly at the national, provincial city, or specific regional level, with the research units mostly being provinces, cities, and counties. A very small number of studies used administrative villages as research units for analysis and discussion [
24]. The recessive morphology of cultivated land is difficult to quantify comprehensively and diversely, so current research on the systematic analysis and discussion of the direction and pattern of the transition, of the recessive morphology of cultivated land, is still relatively scarce. Current research focuses more on the analysis of the process and the driving mechanisms of the transition of the use of the recessive morphology, and there are still deficiencies in the theoretical framework and analytical methods of research on the recessive morphology of cultivated land.
There are currently two main views, in academia, on the definition of the transition morphology of cultivated land use: one is the dominant and recessive morphologies derived from Long Hualou’s theory of regional land use transition patterns; the other is spatial form and functional form, where spatial form refers to the quantity and spatial structure of cultivated land, and functional form refers to the multifunctional expression of cultivated land use [
25]. We believe that the function of cultivated land is one of the attributes of the recessive morphology. As the quality, output and management methods of cultivated land can change with the function of cultivated land, the recessive morphology of cultivated land should, therefore, be the multifunctional expression of cultivated land use.
The foundation of grain production lies in cultivated land, and the use of cultivated land is closely related to food security [
26]. The “Opinions of the CPC Central Committee and the State Council on Doing a Good Job in Promoting Rural Revitalization in 2023” once again emphasized the importance of consolidating the foundation of food security, in all aspects, and strengthening the material basis of storing grain in the ground and in technology. As an important grain production area in China, the Northeast region shoulders the important mission of ensuring national food production safety [
27]. Jilin Province is an important commodity grain production base in the Northeast region. In 2020, the total area of cultivated land in Jilin Province was 737.38 hectares, accounting for 39.38% of the total land area of Jilin Province. In recent years, Jilin Province has undergone a significant transition in cultivated land use, especially considering the conversion from dry land to paddy fields [
28]. Therefore, in this study, Jilin Province, a typical region with a significant transition in cultivated land use and an important grain producing area, was selected as the study area.
Based on the perspective of productive, living, and ecological functions, we built a measurement system for the recessive transition of cultivated land use and the quantification of the recessive morphology of cultivated land. It accurately depicted the process characteristics of the recessive transition of cultivated land use from the perspective of temporal changes and spatial evolution. The conclusions of the study can provide a decision-making basis for local decision-makers to optimize the utilization and management of regional cultivated land in land resource management practice, as well as promote socio-economic transformation by taking advantage of land resources. The study will provide technical support for exploring the optimization and transformation of the utilization of cultivated land in Jilin Province, as well as building a “green-friendly” safe food production pattern by integrating the objectives of regional economic development, food production safety, and ecological environmental protection.
4. Discussion
By combining the long-term trend and spatiotemporal evolution characteristics of the recessive morphology of cultivated land use in Jilin Province, it was found that the transition of cultivated land use in the study area exhibited characteristics of nonlinear evolution. The trend of the recessive morphology of cultivated land use presented a near “S” curve and “stepwise” stage characteristics. According to the change rule of the cultivated land recessive transition comprehensive index in Jilin Province and the position of the trend change of the index trend point on the long-term sequence, this study divided the recessive transition of cultivated land use in Jilin Province into three stages: the “low stage slow rise period”, the “middle stage significant increase period”, and the “high stage steady growth period” (
Figure 11).
Since 1990, agricultural development in Jilin Province has been damaged by the severe droughts in 1997 and 2000 (
Figure 12). Constrained by the level of social–economic development and technological development in Jilin Province, the initial progress of the recessive transition of cultivated land use was slow. The “low stage slow rise period” in the curve of the recessive transition model of cultivated land use in Jilin Province lasted for a relatively long time (from 1990 to 2003, a total of 13 years). Since 2004, accompanied by the transition development of social economy and the improvement of technological level, the recessive transition of cultivated land use in Jilin Province entered a growth period and exhibited significant rapid growth (from 2004 to 2014, a total of 11 years). During this period, Jilin Province suffered from climate disasters that were more unfavorable to agriculture in 2007 and 2009. However, with the progress of agricultural technology and the support of the government, the development of agricultural production has improved, and the cultivated land recessive transition has entered a relatively stable stage (from 2015 to 2020, a total of 6 years).
The essence of the recessive transition of cultivated land use was a dynamic process in which, under the premise of limited cultivated land resources and with the advancement of technology and socio-economic development, in conjunction with regional phase development goals, the productive, living, and ecological functions carried by cultivated land continually conflict, gradually harmonize, conflict again, and ultimately move towards coordination. However, the recessive transition model of cultivated land use proposed in this study is not immutable, but it is a conceptual transition model refined based on the recessive transition process of cultivated land use in Jilin Province. The transition models of each stage adapt to the regional economic, social, and agricultural development stages. Economic and social development, policy interventions, and external interferences are factors that lead to corresponding changes in the stages and speed of cultivated land transition. The influence of natural resources, industrial structure, as well as planning and management methods of cultivated land use on transition dynamics is also an important factor, causing the gradually increasing differences in transition between counties. More importantly, although the research area, the high-value area, the medium-value area, and the low-value area all conformed to the “S” type three-stage transition model, the periods when the sample areas entered the high stage were not consistent, and within the same transition stage, the length of the transition experienced by each county also differed. For example, the Baicheng City jurisdiction went through a 17 year period of significant increase in the mid-term, and it entered the “high stage steady growth period” in 2017. Changling County’s “middle stage significant increase period” lasted for 10 years, and it entered the “high stage steady growth period” in 2011. Furthermore, not all study units followed this model to experience the transition of the recessive morphology of cultivated land use. Some areas did not experience the first stage during the research period (Qian Gorlos County) and did not enter the third stage (Hunchun City). Therefore, the transition of cultivated land use cannot be considered as a given model [
50].
Based on the discussion of the spatio-temporal evolution of the recessive transition of cultivated land use in Jilin Province, this study revealed the internal mechanism of the recessive transition of cultivated land in Jilin Province from the perspective of “three-function synergy”, and it constructed a model of the recessive transition of cultivated land use in Jilin Province. Due to different dominant factors (social and economic development, policy intervention) at different stages, the recessive transition process presented similar “ladder-type” stage characteristics. The results of this study are similar to and different from the results of other scholars assessing other regions. On the one hand, the model of recessive cultivated land shift in Jilin Province that we obtained is similar to other scholars’ models, which is an abstract S-shaped curve. However, the model was influenced by natural conditions, such as topography and fertility, and it was adapted to regional economic, social, and agricultural development stages. Different regions have different lengths of time for each stage. For example, the results of the study by Niu, S. et al. showed that the comprehensive transition index of cultivated land utilization in the Huaihai Economic Zone of China increased, overall, from 2002 to 2017 [
25]. Li, X., etc., found that the recessive transition of cultivated land, in the Huaibei region of the Jiangsu Province, declined slightly from 1995 and, then, showed a staged increase from 2004 [
35]. Lyu, L. et al. found that the crop production, living security, and eco-environmental function of farmland in Sihong County showed a trend of first decreasing and then increasing [
51].
From the perspective of Jilin Province, due to the influence of the economic development level, drought, and flood disasters, the level of cultivated land use was low; therefore, the first stage of the recessive transition of cultivated land use in Jilin Province lasted longer (11 years) and remained in a slow rise. After 2003, the transition model entered the second stage. Economic growth and agricultural development were regulated by policies and systems, effectively promoted the process and trend of recessive transition, and the recessive transition of cultivated land use turned to a significant increase. Due to the limitation of resource and environmental carrying capacity, the degree of transition could not increase indefinitely. After entering the high stage of stable growth, the speed of the recessive transition of cultivated land use in Jilin Province slowed down.
As the basic unit of cultivated land resource use, villages and farmers can more accurately present the micro characteristics of recessive cultivated land-use shift. Therefore, it is the direction of future research to seek to depict the characteristics and internal mechanisms of the recessive transition of cultivated land use at the micro scale. In addition, the recessive morphology of cultivated land use has multiple attributes such as quality, property rights, operation mode, input, output, and function. Limited by data availability, this study did not quantitatively research the property rights and operation mode of cultivated land, nor did it research the impact of policies. Therefore, subsequent research should pay attention to the changes in ownership and policies related to cultivated land, and it should construct a more scientific and perfect indicator system of recessive transition of cultivated land, to reveal the characteristics of recessive transition of cultivated land use in a more systematic way, in order to better achieve scientific management and the sustainable use of land resources.