25 August 2023, Volume 33 Issue 8 Previous Issue   
Special Issue: Human-environment interactions and Ecosystems
Time-scale effects in human-nature interactions, regionally and globally
LI Yu, GAO Mingjun, ZHANG Zhansen, ZHANG Yuxin, PENG Simin
2023, 33 (8):  1569-1586.  doi: 10.1007/s11442-023-2143-5
Abstract ( )   HTML ( )   PDF (2870KB) ( )  

Spatial-temporal scales effects are general among human-nature interactions. However, the laws and mechanisms of the interaction between humans and the environment at different spatial-temporal scales remain to be identified. The Hexi Corridor in Northwest China is located in the eastern section of the Silk Road and is one of the world’s first long-distance cultural exchange centers. Here we present a comprehensive dataset of the Hexi Corridor, including changes in environments, population, wars, famines, settlements, and ancient oases from the Neolithic to the historic period. Results show that humans adapt to climate change on the millennium scale by choosing corresponding production methods. Environmental change, civilization evolution, and dynasty replacement interrelate on the decadal and centennial scales. Social crises are closely linked to extreme weather events on the interannual scale. On the basis of these results, we find similar time scale effects in the world’s major ancient civilizations. We do so by analyzing their processes of civilization evolution.

Figures and Tables | References | Related Articles | Metrics
Remote sensing assessment of the ecological benefits provided by national key ecological projects in China during 2000-2019
SHAO Quanqin, LIU Shuchao, NING Jia, LIU Guobo, YANG Fan, ZHANG Xiongyi, NIU Linan, HUANG Haibo, FAN Jiangwen, LIU Jiyuan
2023, 33 (8):  1587-1613.  doi: 10.1007/s11442-023-2144-4
Abstract ( )   HTML ( )   PDF (5295KB) ( )  

We propose a theoretical framework for assessing the ecological benefits provided by key national ecological projects in China over the past 20 years. A dataset consisting of six primary indicators and nine secondary indicators of ecosystem structure, ecosystem quality, and ecosystem services for 2000-2019 was generated using ground survey and remote sensing data. Ecological benefits were quantitatively evaluated following the implementation of these projects in China. Areas with medium, relatively high, and high degrees of ecological restoration accounted for 24.1%, 11.9%, and 1.7% of the national land, respectively. Degrees of ecological restoration were higher in areas with greater numbers of ecological projects. Areas with relatively and absolutely high degrees of ecological restoration were mainly concentrated in the Loess Plateau, the farming-pastoral zone of northern China, the Northeast China Plain, and an area spanning the borders of Sichuan, Yunnan, Guizhou, Chongqing, and Hunan. The relative contributions of climatic factors and ecological projects to changes in vegetation net primary productivity were 85.4% and 14.6%, respectively, and the relative contributions of climatic factors and ecological projects to changes in water erosion modulus were 69.5% and 30.5%, respectively. The restoration potential of national vegetation coverage was 20%, and the restoration potential percentage of forest and grassland vegetation coverage was 6.4% and 23%, respectively. Climatic conditions can inhibit ecological restoration. Areas with relatively high and high degrees of ecological restoration were mainly distributed in areas with an average annual temperature greater than 0°C and annual precipitation greater than 300 mm. Therefore, the limitations associated with climate conditions require consideration during the implementation of national ecological projects. The implementation of combined measures should be emphasized, and the benefits of ecological investment funds should be maximized.

Figures and Tables | References | Related Articles | Metrics
Spatiotemporal patterns of human and wild boar conflicts in rural China and its implications for social-ecological systems coevolution
WANG Yahui, YANG Aoxi, YANG Qingyuan, KONG Xiangbin, FAN Hui
2023, 33 (8):  1614-1630.  doi: 10.1007/s11442-023-2145-3
Abstract ( )   HTML ( )   PDF (7059KB) ( )  

In the context of social and economic transformation in rural China, ecosystem disservices have emerged frequently. This study reveals the spatiotemporal patterns, hazards and driving factors of wild boar damage from 2000 to 2021 by using the meta-analysis and collecting 733 typical human and wild boar conflicts. In this period, the number, spatial scope and hazard degree of wild boar damage incidents showed an increasing trend, and the number of provincial-level regions, prefecture-level cities and districts (counties) involved increased from 18, 41 and 67 to 25, 147 and 399, respectively. Wild boar damage incidents were concentrated in Chongqing municipality and central and western Hubei province before 2005, and then expanded to the Sichuan Basin, Loess Plateau, middle-lower reaches of Yangtze River and mountainous areas such as Changbai Mountains after 2015. The main manifestations were destroying crops, infringing poultry and causing casualties, especially the destruction of crops and farmland abandonment, accompanied by a rapid increase in casualties, accounting for 23.66% of the damage incidents. Meanwhile, the spreading trend and harmfulness of wild boar damage is a typical phenomenon of ecosystem disservices. The aggravation of this phenomenon is the result of ecological restoration, hunting ban policy, unclear boundary between agricultural land and ecological land, strong viability of wild boar and lack of natural enemies. This has posed an obvious threat to the use of abandoned farmland, the improvement of farmers’ livelihood and the maintenance of regional ecological security. It is urgent to formulate a policy of controlling the number of wild boars and establish a compensation mechanism for the loss by wild boars.

Figures and Tables | References | Related Articles | Metrics
Quantitative assessment of fire occurrence Dead Fuel Index threshold and spatio-temporal variation in different grassland types of China-Mongolia border area
CHAO Lumen, BAO Yulong, ZHANG Jiquan, BAO Yuhai, MEI Li, YUAN Zhihui
2023, 33 (8):  1631-1659.  doi: 10.1007/s11442-023-2146-2
Abstract ( )   HTML ( )   PDF (13854KB) ( )  

Climate change is manifesting rapidly in the form of fires, droughts, floods, resource scarcity, and species loss, and remains a global risk. Owing to the disaster risk management, there is a need to determine the Dead Fuel Index (DFI) threshold of the fire occurrence area and analyze the spatio-temporal variation of DFI to apply prevention measures efficiently and facilitate sustainable fire risk management. This study used the MODIS Burned Area Monthly L3 (MCD64A1), Landsat Global Burned Area (BA) products, and MODIS Surface Reflectance 8-Day L3 (MOD09A1) data from 2001 to 2020 to calculate the values of the DFI in the study area before the occurrence of fire. The results showed that: (1) The inversion of the meadow steppe DFI values in the fire area was distributed in the range of 14-26, and the fire rate was the highest in the range of 20-22. The inversion of the typical steppe DFI values in the fire area was distributed in the range of 12-26, and the fire rate was the highest in the range of 16-22. (2) Areas with high fire DFI values included Khalkhgol, Matad, Erdenetsagaan, Bayandun, Gurvanzagal, Dashbalbar in Mongolia, and scattered areas of the Greater Khingan Mountains (forest edge meadow steppe area), East and West Ujumqin Banner, and Xin Barag Right Banner. The highest fire probability of fire occurred during October and April. (3) The DFI values were sensitive to changes in altitude. The results of this study may provide useful information on surface energy balance, grassland carbon storage, soil moisture, grassland health, land desertification, and grazing in the study area, especially for fire risk management.

Figures and Tables | References | Related Articles | Metrics
Understanding the spatial heterogeneity of grazing pressure in the Three-River-Source Region on the Tibetan Plateau
GU Changjun, LIU Linshan, ZHANG Yili, WEI Bo, CUI Bohao, GONG Dianqing
2023, 33 (8):  1660-1680.  doi: 10.1007/s11442-023-2147-1
Abstract ( )   HTML ( )   PDF (8953KB) ( )  

Elucidating the distribution of the grazing pressure requires an understanding of the grazing activities. In this study, we analyzed the grazing behavior of yaks in Three-River- Source Region (TRSR) and identified the main factors influencing the distribution of grazing intensity (GI) using trajectory data and remote sensing datasets. Our results revealed that a semi-resident transhumance strategy is employed in this region. The average grazing time (GT) of four GPS collars over the year was 11.84 h/day (N6), 11.01 h/day (N11), 9.25 h/day (N18), and 11.61 h/day (N24). GT was generally higher in warm seasons (summer and autumn) than in cold seasons (spring and winter). The average daily moving speed was found to be closely related to the pasture size of different herders and the seasons. Geodetector analysis identified the distance to camp (DOC) as the most important single factor influencing the distribution of GI, explaining up to 52% of the GI variations. However, relying solely on this factor may not accurately depict the actual GI distribution. When pairwise factors interacted, the explanatory power of the model increased, ranging from 34.55% to 63.26%. Our study highlights the importance of considering multiple factors when predicting grazing intensity, as grazing activities tend to cluster near settlements, but other factors may also be influential.

Figures and Tables | References | Related Articles | Metrics
Dynamics and interactions of water-related ecosystem services in the Yellow River Basin, China
WANG Peng, XU Mingxiang
2023, 33 (8):  1681-1701.  doi: 10.1007/s11442-023-2148-0
Abstract ( )   HTML ( )   PDF (6209KB) ( )  

Climate change and human activities have profoundly altered ecosystem services in the Yellow River Basin (YRB) since the Grain for Green project was implemented, but have not been accurately revealed on a year-by-year scale. This study combined the InVEST model to reveal the year-by-year changes in the water-related ecosystem services (WRESs) in YRB during 1990-2020, including water yield, soil conservation and water purification services. The trade-off/synergy of WRESs and impacts of land management measures on WRESs were assessed fully. The results showed that from 1990 to 2020, cropland and barren land were considerably converted to forest and grassland in YRB. WRESs were continuously improved as a result of increase of water yield and reductions of soil export and nitrogen export, at rates of +1.11 mm·yr-1, -0.23 t·km-2·yr-1 and -1.01 kg·km-2·yr-1, respectively. We found that in YRB water purification service showed trade-off relationships with soil conservation and water yield services in recent decades, and water yield and soil conservation maintained a synergitic effect. Additionally, the revegetation measures showed a potential of enhancing soil conservation and water purification, but reducing water yield. This study provided a thorough understanding of WRESs dynamics and a valuable reference for the ecological restoration practices.

Figures and Tables | References | Related Articles | Metrics
Impact of labor transfer differences on terraced fields abandonment: Evidence from micro-survey of farmers in the mountainous areas of Hunan, Fujian and Jiangxi
XIE Hualin, WU Qing, LI Xiubin
2023, 33 (8):  1702-1724.  doi: 10.1007/s11442-023-2149-z
Abstract ( )   HTML ( )   PDF (792KB) ( )  

In recent years, the phenomenon of abandonment of cultivated land in mountainous areas has occurred frequently, and the problem of abandonment has become a focus of attention of government agricultural departments and academic circles. However, few studies have paid attention to the impact of differences in labor transfer on the abandonment behavior of farmers’ terraced fields. Based on this, this paper takes the terraced fields of Hunan, Fujian and Jiangxi provinces as the research area, combined with data from 1438 farmer households, and uses the Probit and Tobit models to analyzed the impact of the difference in the quantity, distance and quality of labor off-farm transfer on the decision-making and scale of terraced field abandonment of farmer households. The results show that: (1) The greater the quantity of labor transfer, the farther the transfer distance and the higher the quality of non-agricultural employment, can promote the decision of farmers to abandon terraced fields; (2) With the deepening of the degree of non-agricultural transfer, the scale of abandoned terraced fields by farmers in hilly and mountainous areas will also expand; (3) The distance and quality of labor transfer can strengthen the impact of labor transfer quantity on farmers’ decision to abandon land. To alleviate the phenomenon of abandoned terraced fields, the government should pay attention to the labor substitution role of agricultural service outsourcing and mechanization in mountainous areas. The government should actively promote the transformation of terraced fields into mechanized farming, improve the cultivated land transfer market, and encourage farmers to transfer terraced fields.

Figures and Tables | References | Related Articles | Metrics
Estimation of maize yield incorporating the synergistic effect of climatic and land use change in Jilin, China
WEN Xinyuan, LIU Dianfeng, QIU Mingli, WANG Yinjie, NIU Jiqiang, LIU Yaolin
2023, 33 (8):  1725-1746.  doi: 10.1007/s11442-023-2150-6
Abstract ( )   HTML ( )   PDF (7813KB) ( )  

Yield forecasting can give early warning of food risks and provide solid support for food security planning. Climate change and land use change have direct influence on regional yield and planting area of maize, but few studies have examined their synergistic impact on maize production. In this study, we propose an analysis framework based on the integration of system dynamic (SD), future land use simulation (FLUS) and a statistical crop model to predict future maize yield variation in response to climate change and land use change in a phaeozem region of central Jilin province, China. The results show that the cultivated land is likely to reduce by 862.84 km2 from 2030 to 2050. Nevertheless, the total maize yield is expected to increase under all four RCP scenarios due to the promotion of per hectare maize yield. Among the scenarios, RCP4.5 is the most beneficial to maize production, with a doubled total yield in 2050. Notably, the yield gap between different counties will be further widened, which necessitates the differentiated policies of agricultural production and farmland protection, e.g., strengthening cultivated land protection and crop management in low-yield areas, and taking adaptation and mitigation measures to coordinate climate change and production.

Figures and Tables | References | Related Articles | Metrics
Variation of gross primary productivity dominated by leaf area index in significantly greening area
CHEN Xin, CAI Anning, GUO Renjie, LIANG Chuanzhuang, LI Yingying
2023, 33 (8):  1747-1764.  doi: 10.1007/s11442-023-2151-5
Abstract ( )   HTML ( )   PDF (8591KB) ( )  

The leaf area index (LAI) shows a significant increasing trend from global to regional scales, which is known as greening. Greening will further enhance photosynthesis, but it is unclear whether the contribution of greening has exceeded the CO2 fertilization effect and become the dominant factor in the gross primary productivity (GPP) variation. We took the Yangtze River Delta (YRD) of China, where cropland and natural vegetation are significantly greening, as an example. Based on the boreal ecosystem productivity simulator (BEPS) and Revised-EC-LUE models, the GPP in the YRD from 2001 to 2020 was simulated, and attribution analysis of the interannual variation in GPP was performed. In addition, the reliability of the GPP simulated by the dynamic global vegetation model (DGVM) in the area was further investigated. The research results showed that GPP in the YRD had three significant characteristics consistent with LAI: (1) GPP showed a significant increasing trend; (2) the multiyear mean and trend of natural vegetation GPP were higher than those of cropland GPP; and (3) cropland GPP showed double-high peak characteristics. The BEPS and Revised-EC-LUE models agreed that the effect of LAI variation (4.29 Tg C yr-1 for BEPS and 2.73 Tg C yr-1 for the Revised-EC-LUE model) determined the interannual variation in GPP, which was much higher than the CO2 fertilization effect (2.29 Tg C yr-1 for BEPS and 0.67 Tg C yr-1 for the Revised-EC-LUE model). The GPP simulated by the 7 DGVMs showed a huge inconsistency with the GPP estimated by remote sensing models. The deviation of LAI simulated by DGVM might be a potential cause for this phenomenon. Our study highlights that in significant greening areas, LAI has dominated GPP variation, both spatially and temporally, and DGVM can correctly simulate GPP only if it accurately simulates LAI variation.

Figures and Tables | References | Related Articles | Metrics