Increase In Land-use Intensity Research Articles

Carbon surplus or carbon deficit under land use transformation in China?

With the progression of industrialization and urbanization, terrestrial ecosystems have experienced varying degrees of degradation in their carbon sequestration capabilities, leading to functional loss in some regions. Consequently, the issue of reducing emissions and enhancing carbon sinks, especially in addressing the carbon imbalance brought on by urban and industrial developments, has become a focal point for international organizations and the academic community. Existing studies have separately investigated the effects of changes in single land use types, such as built-up land, forest land, and cropland, on carbon emissions or carbon sequestration. However, few studies have discussed carbon emissions and carbon sequestration within the same framework. This study, based on remote sensing data from 2000 to 2020, utilizes spatial autocorrelation analysis and spatial Durbin model to reveal the long-term trends in land use intensity and carbon balance in China. It was found that the carbon balance index decreased annually by 3.42%, from 0.2406 to 0.0760 during that period. In particular, the eastern and central regions of China exhibited increasingly evident carbon deficits, with most areas along the southeastern coast transitioning from a carbon surplus to a carbon deficit. Over two decades, China’s land use intensity and carbon balance developed a stronger negative spatial dependence. The spatial match and mismatch between land use intensity and carbon deficit are the primary clustering types for their spatial correlation. Each unit increase in land use intensity decreased the local city carbon balance by 0.755 but raised the carbon balance in adjacent areas by 2.740. This indicates that land use intensity impacts the local carbon balance negatively but benefits neighboring regions. There is also evident spatial inequality in different economic zones, with the strongest impact in the Northeast, followed by the Western, Eastern, and Central regions. The resolution of these issues reveals the spatial inequalities and remote driving effects of land use transformation on carbon balance across different scales, from the “entire region” to “economic divisions”. The results of this study provide theoretical and empirical evidence for emissions reduction and carbon sequestration in cities at different levels of land use intensity.

Spatiotemporal differentiation of the ecosystem service value and its coupling relationship with urbanization: A case study of the Lanzhou-Xining urban agglomeration

Urbanization is a key factor that threatens the stability of ecosystem services (ESs), which are crucial for maintaining ecological security and enhancing human quality of life. Gaining insight into the spatiotemporal differentiation of the ecosystem service value (ESV) and its coupling relationship with urbanization is a key issue in promoting sustainable regional development. We employed various algorithms, including the improved equivalence factor method, random forest model, mixed geographically and temporally weighted regression model, and coupling coordination degree (CCD) model, to reveal the spatiotemporal evolution of the ESV and its driving mechanisms in the Lanzhou-Xining urban agglomeration (LXUA) from 1980 to 2020. In addition, we explored the coupling relationship between ESV and the combined urbanization index (CUI). The results showed the following: (1) From 1980 to 2020, the interannual variation in ESV first decreased and then increased, with an increase of 230 million yuan/annum in 2020 compared to that of 1980. Spatially, the ESV exhibits a distribution pattern of high in the south and low in the north, and high in the west and low in the east. (2) Land use intensity (LUI) and elevation contributed degree values exceeding 20% to the ESV and were the most important drivers of the ESV. (3) From 1980 to 2020, the average CCD values of the ESV and CUI transitioned from being severely unbalanced (0.19) to being slightly balanced (0.42). There was a negative spatial correlation between the ESV and CUI, with each cluster type was distributed discretely in space. Our study emphasizes that in areas characterized by robust ecosystem integrity and a high ESV, the increase in LUI was constitutes the main reason for the decline in the ESV. The findings of this study can provide a scientific basis for the coordinated development of ESVs and urbanization in the LXUA and other cities.

Ecosystem degradation or restoration? The evolving role of land use in China, 2000-2020.

Dramatic land use change in China affects ecosystem degradation and restoration. Identifying the evolving role of land use in ecosystem degradation and restoration in China is essential for sustainable land policy making. However, it is not clear how land use affects ecosystem degradation and restoration over time. Here, we used the revised benefit transfer approach and spatial statistics based on land use data to determine the evolving role that land use plays in ecosystem degradation and restoration in China during 2000-2020. The study results pointed out that the deterioration of the forestland ecosystem during the study period was the main reason for ecosystem degradation, while the conversion of arable land to forestland was the main cause for ecosystem restoration. Every 1% increase of land use intensity in the periods 2000-2005, 2005-2010, 2010-2015, and 2015-2020 resulted in -1.754%, 0.697%, 1.098%, and -0.058% of the changes in ecosystem services, respectively. This study provided important policy implications for future sustainable land use management in China.

Assessing spatial heterogeneous response of ecosystem service relationships to land use intensification

Sustainable land use should balance the competing needs for development and protection. Land-use intensification facilitates material benefits from ecosystem, while potentially undermining the capacity of regulate the life-support environment and thus altering trade-offs between ecosystem services (ES). However, there remains a limited understanding of how land-use intensity (LUI) affects the spatial heterogeneity of ES relationships. To address this issue, we first propose an ES synergies (ESS) index, to clarify site-specific ES relationships, based on a combination of the production possibility frontier (PPF) and the technique for order preference by similarity to the ideal solution (TOPSIS). Then, we assess the nonlinear impacts of LUI on ESS, using the generalized additive models (GAMs). A case study was conducted in the Three Gorges region of central China, due to the dilemma between intensive development for poverty alleviation and water-soil retention for ecological protection. The results showed that an increase in LUI caused different rates of decline in ESS. Land-use intensification increased resource inputs and anthropogenic disturbances within entire land parcels, thus disrupting the synergistic relationships between several ES. Specifically, the synergies between water retention and carbon sequestration or biodiversity conservation decreased by more than three times as much as those between water retention and food production. Excessive LUI will reduce the provision of carbon sequestration and biodiversity conservation compared to that of food production for the same level of water retention. However, moderate LUI can promote the synergistic provision of multiple services. For example, an LUI threshold of 2.5, which maximized the synergies of water-soil retention with other ES, showed the optimal balance of diverse ecological benefits at the highest level of intensity. Our study is expected to extend existing knowledge on the spatial heterogeneity of ES relationships by considering site-specific land use, and to mitigate the costs of land management due to ES trade-offs.

Improving kettle holes as habitat and reproduction areas for amphibians – a case study in organic farms in north-eastern Germany

Abstract Kettle holes are found in young moraine landscapes and serve as an important habitat for amphibians. The loss of amphibians has been dramatic in recent decades, mainly because of the increase in land use intensity and deterioration of habitats e.g., kettle holes in agricultural landscapes. We monitored amphibian species on three organically managed farms in north-eastern Germany to get an overview of their occurrence and proof of reproduction to develop effective protection strategies. From 2016 to 2020, we investigated 50 kettle holes in cultivated fields. In 2018, we implemented the nature conservation measure ‘cutting back dense wooded belts’ in six of these kettle holes. Here, we focused on seven species considering four highly endangered species. We found six to seven species in up to 17 kettle holes in the 44 kettle holes without the measure ‘cutting back dense wooded belts’. Bombina bombina occurred at the most kettle holes (57%). The number of kettle holes where amphibians reproduced differed strongly. On average, at least one species reproduced at 58% of the kettle holes. Many kettle holes become overgrown with negative effects for amphibians due to the reduction in solar irradiation and higher water consumption. The nature conservation measure increased the number of species on average from two to four and the number of species with reproduction from one to three. It is one of more than 100 measures in the ‘Farming for Biodiversity’ project that farmers can choose to receive a nature conservation certificate, which can be used for marketing purposes.

Change in land-use structure due to urbanisation in China

Evidence on the influence of urbanisation on land-use structure in China can provide a scientific basis for sustainable land-use and ecological protection. However, previous studies have not completely explained the mechanisms of land-use structure change during rapid urbanisation. To address this gap, in the present study, the land-use intensity and information entropy of land-use structure from 1980 to 2020 were measured to represent urbanisation level and land-use structure for the corresponding period using land-use/cover datasets in China. The impact of urbanisation on the information entropy of land-use structure was analysed from multiple perspectives based on a set of panel regression models. The results showed that the land-use intensity in China presented a continuously increasing trend, whereas information entropy of land-use structure exhibited an increasing and then decreasing tendency during the study period. There was a significant spatial dependence between land-use intensity and information entropy of land-use structure in China, as indicated by the inverted U-shaped curve. We found that the higher the economic development level, the greater the threshold values. In addition, a 1% increase in land-use intensity in a region with a better economic development level might lead to a greater increase in the information entropy of land-use structure. The findings of this study indicated that a combination of cross-regional collaborative governance and differentiated management strategies is effective in optimising land-use structure during rapid urbanisation in China and other countries.

Short term effects of climate change and intensification of management on the abundance of microbes driving nitrogen turnover in montane grassland soils.

Montane grasslands in Europe are exposed to increasing temperatures twice as fast as the global average. Changes in climatic conditions are possibly accompanied by an increase in land use intensity, caused by a prolongation of the vegetation period and the need to improve productivity. Therefore, the investigation of combined effects of climate change and land use intensity is needed to further implement agricultural management strategies. Here we present results from a study performed in the pre-alpine region of southern Germany, where intact plant-soil mesocosms from grasslands, were translocated along an altitudinal gradient, resulting in an increase in soil temperature (moderate treatment: +0.5 K; strong treatment: +1.9 K warming) during the experimental period. Additionally, we applied an extensive or intensive agricultural management (two vs. five times of mowing and slurry application) on the transplanted mesocosms. After an exposure of one year, we measured plant growth and soil properties and quantified abundances of soil microorganisms catalyzing key steps in the nitrogen (N) cycle. Our data indicate, significant interactions between climate change and management. For example, microbial biomass was significantly reduced (-47.7% and -49.8% for Cmic and Nmic respectively), which was further accompanied by lower abundances of N2-fixing bacteria (up to -89,3%), as well as ammonia oxidizing bacteria (-81.4%) under intensive management, whereas N-mineralizing bacteria increased in abundance (up to +139.8%) under extensive management. Surprisingly, the abundances of denitrifying bacteria as well as mean N2O emissions were not affected by the treatments. Overall, our data suggest pronounced shifts in the abundance of microbes driving the N cycle in soil as a result of combined climate change and land use intensification already after a short simulation period of one year.

Plant-Pollinator Networks in Savannas of Burkina Faso, West Africa

West African savannas are severely threatened with intensified land use and increasing degradation. Bees are important for terrestrial biodiversity as they provide native plant species with pollination services. However, little information is available regarding their mutualistic interactions with woody plant species. In the first network study from sub-Saharan West Africa, we investigated the effects of land-use intensity and climatic seasonality on plant–bee communities and their interaction networks. In total, we recorded 5686 interactions between 53 flowering woody plant species and 100 bee species. Bee-species richness and the number of interactions were higher in the low compared to medium and high land-use intensity sites. Bee- and plant-species richness and the number of interactions were higher in the dry compared to the rainy season. Plant–bee visitation networks were not strongly affected by land-use intensity; however, climatic seasonality had a strong effect on network architecture. Null-model corrected connectance and nestedness were higher in the dry compared to the rainy season. In addition, network specialization and null-model corrected modularity were lower in the dry compared to the rainy season. Our results suggest that in our study region, seasonal effects on mutualistic network architecture are more pronounced compared to land-use change effects. Nonetheless, the decrease in bee-species richness and the number of plant–bee interactions with an increase in land-use intensity highlights the importance of savanna conservation for maintaining bee diversity and the concomitant provision of ecosystem services.

Land-use intensity indirectly affects soil multifunctionality via a cascade effect of plant diversity on soil bacterial diversity

Land-use intensification impairs multiple soil ecosystem functions and services (hereafter ‘soil multifunctionality’; SMF) crucial to human wellbeing by influencing plant diversity and soil microbial communities. However, available information is limited on the contrasting and interaction effects of plant diversity and soil microbial communities on SMF under a gradient of land-use intensity (LUI). We measured five soil ecosystem functions associated with effective soil nutrients and water retention along 15 LUI gradients on Hainan Island, where land-use change and biodiversity loss has been severe. We used phospholipid fatty acid (PLFA) method to determine the diversity and composition of soil microbial communities. The relationships among LUI, plant diversity (species and functional diversity), soil microbial diversity (bacterial and eukaryotic diversity), and soil microbial composition (fungi/bacteria and Gram-positive/Gram-negative bacteria ratios), and SMF were examined. The LUI affected SMF indirectly by reducing plant diversity and its interaction with soil bacterial diversity. Specifically, with increase in LUI, loss of plant species diversity indirectly reduced SMF via reduction of soil bacterial diversity. In contrast, loss of tree height diversity reduced SMF directly and indirectly through decrease in soil bacterial diversity. Importantly, the indirect effect of LUI mediated by tree height diversity was stronger than that mediated by plant species diversity and soil bacterial diversity. These results provide evidence that the cascade effect of plant diversity to soil bacterial diversity mediates the impacts of land-use intensity on soil multifunctionality, and further suggest that focusing on tree height diversity may be helpful for sustainable ecosystem management and predicting the impacts of land use changes.

An Effective Way to Map Land-Use Intensity with a High Spatial Resolution Based on Habitat Type and Environmental Data

Mapping and monitoring agricultural land-use intensity (LUI) changes are essential for understanding their effects on biodiversity. Current land-use models provide a rather coarse spatial resolution, while in-situ measurements of LUI cover only a limited extent and are time-consuming and expensive. The purpose of this study is to evaluate the feasibility of using habitat type, topo-climatic, economic output, and remote-sensing data to map LUI at a high spatial resolution. To accomplish this, we first rated the habitat types across the agricultural landscape in terms of the amount and frequency of fertiliser input, pesticide input, ploughing, grazing, mowing, harvesting, and biomass output. We consolidated these ratings into one LUI index per habitat type that we then related to topo-climatic, economic output, and remote-sensing predictors. The results showed that the LUI index was strongly related to plant indicator values for mowing tolerance and soil nutrient content and to aerial nitrogen deposition, and thus, is an adequate index. Topo-climatic, and, to a smaller extent, economic output and remote-sensing predictors, proved suitable for mapping LUI. Large- to medium-scale patterns are explained by topo-climatic predictors, while economic output predictors explain medium-scale patterns and remote-sensing predictors explain local-scale patterns. With the fine-scale LUI map produced from this study, it is now possible to estimate within unvarying land-use classes, the effect on agrobiodiversity of an increase in LUI on fertile and accessible lands and of a decrease of LUI by the abandonment of marginal agricultural lands, and thus, provide a valuable base for understanding the effects of LUI on biodiversity. Due to the worldwide availability of remote-sensing and climate data, our methodology can be easily applied to other countries where habitat-type data are available. Given their low explanatory power, economic output variables may be omitted if not available.

近30年辽东湾北部区土地利用强度与生态系统服务价值的时空关系

PDF HTML阅读 XML下载 导出引用 引用提醒 近30年辽东湾北部区土地利用强度与生态系统服务价值的时空关系 DOI: 10.5846/stxb201903120471 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（41571122）；辽宁省自然科学基金项目（20180551194）；辽宁省教育厅科研专项（H201783631，H201783623） Spatial and temporal relationships between land use intensity and the value of Ecosystem Services in northern Liaodong Bay over the past 30 years Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:探讨滨海湿地土地利用强度与生态系统服务价值的时空关系，是促进滨海湿地资源合理配置及维持生态系统可持续发展的重要依据。基于辽东湾北部区1985、1993、2002、2014年4期Landsat TM遥感数据，在计算土地利用强度综合指数的基础上，运用地统计学方法及地理加权回归模型探讨土地利用强度与生态系统服务价值的时空耦合关系，结果表明：1）1985-2014年，生态系统服务价值变化显著，其中水域占比最大，滩涂和草地次之。2）研究区单位面积生态系统服务价值在空间上总体呈现由南高北低向西高东低演变的趋势。3）研究区土地利用强度与生态系统服务价值之间整体呈强烈的负相关关系，当土地利用强度增加时，生态系统服务价值降低。4）随着土地利用强度的增加，四种服务类型之间出现以供给服务价值的增加而导致其他服务类型价值减少的权衡关系。 Abstract:Discussing spatial and temporal relationships between land use intensity and the value of ecosystem services in coastal wetlands provides an important foundation to promote the rational allocation of coastal wetland resources and the sustainable development of ecosystems. Based on an equivalent factor method and four periods of Landsat TM remote sensing data of the northern Liaodong Bay (1985, 1993, 2002, and 2014), this paper uses geostatistical methods and a geo-weighted regression model to study the spatial and temporal relationships between land use intensity and the value of ecosystem services based on the calculation of the comprehensive index of land use intensity in the study area. The results showed that: 1) from 1985 to 2014, the value of ecosystem services changed significantly, and the largest value was associated with the water area, followed the beach and grassland areas. Aquaculture provided more and more value, while bare land provided the least. 2) In the study area, the value of ecosystem services per unit area has spatially evolved from high value in the south and low value in the north to high value in the west and low value in the east. The ecological advantages of the southern area gradually weakened and eventually disappeared. 3) There was a strong negative correlation between land use intensity and the value of ecosystem services. As land use intensity increased, the value of ecosystem services decreased. 4) With the increase of land use intensity, there was a trade-off relationship among the four service types, that is the value of other service types decreased due to the increase of supply service value. The correlation between land use intensity and the value of ecosystem services was stronger in the southern part of the study area. 参考文献 相似文献 引证文献

Impacts of agricultural intensification on arable plants in extensive mixed crop-livestock systems

Populations of segetal species are facing sharp declines in Europe due to agricultural intensification. To better conserve them, it is important to assess the effect of intensification in extensive mixed crop-livestock systems, which are considered hotspots for segetal species. The aim of this study was to evaluate how certain key farming practices and land-use intensity affect the composition, species richness and abundance of segetal species, taking into account spatial heterogeneity within the studied fields. To do this, we sampled 94 winter cereal fields - 41 farmed organically and 53 farmed conventionally - along a gradient of land-use intensity. At field scale, we found that both the species richness and the abundance of segetal taxa decreased with an increase in land-use intensity. The results also showed significant differences in segetal taxa composition, species richness and abundance between the edges and the inner-fields location and these differences significantly increased with land-use intensity. The species richness and abundance of both common and threatened segetal taxa were significantly higher at the edges of fields than within them. Herbicide treatments had a significant negative impact on segetal taxa species richness and abundance, while mechanical weeding had a positive impact on abundance. Nitrogen inputs had a significant detrimental effect only on the abundance of common segetal taxa. Crop seed origin and the ratio of cereal crops in the rotational cycle had no effect on segetal taxa species richness and abundance. Despite these impacts, we found that segetal species richness and abundance were better explained by farm identity (random factor) than by current management (fixed factors). Variation in segetal species richness and abundance between fields of the same farm and between farms reflect the long-term effects of farming practices and the history of seed transfer between farms more than by current management practices. In our study area, the production of cereals is destined for the consumption of the farm's sheep and the fact the cereals are not marketed makes it possible to tolerate the presence of segetal species in higher proportions than in intensive farming systems.

Linking the human appropriation of net primary productivity-based indicators, input cost and high nature value to the dimensions of land-use intensity across French agricultural landscapes

The intensification of European land use accelerated substantially in a few decades, particularly in agro-ecosystems that are facing an increasing demand for agricultural products and whose area is also constrained by other uses (e.g. urbanization). Increases in land use intensity (LUI) are characterized by increases of the agricultural outputs per land unit through management practices and/or by increasing amounts of inputs. LUI is a complex and multi-dimensional issue in which each dimension needs to be considered to have a better understanding of the impact of LUI on ecosystem functioning and biodiversity. Here, we focused on five existing LUI indicators: the Input Cost per hectare (IC/ha), assessing the expenses in inputs (fertilizers, pesticides, etc.), the High Nature Value (HNV), a scoring system of agricultural areas accounting for the presence of landscape elements and practices favorable to biodiversity, and three indices of the Human Appropriation of Net Primary Productivity (HANPP) framework, i.e. the harvested biomass (HANPPharv), the living biomass flow remaining available after harvests (NPPeco) and HANPP which combines harvested biomass and effects of land use conversion. First, we discussed how these indicators can relate to the dimensions of LUI. Then, we tested whether HANPP, HANPPharv and NPPeco were redundant with IC/ha and HNV throughout 25,758 French metropolitan municipalities, using Pearson’s correlation coefficient and Linear Mixed-effects Models, while accounting for climatic and landscape parameters. As expected, HANPP, NPPeco and HANPPharv were highly correlated with each other, but weakly to HNV and IC/ha. HNV showed a positive relationship with NPPeco but negative with HANPP and HANPPharv. The opposite findings were observed with IC/ha. These three indicators seem complementary to HNV and IC/ha indicators, linking farmland structural properties and inputs intensity. Finally, we showed how these indicators can be linked, i.e. particular combinations of the indicator values could reveal contrasting agro-ecosystems types (e.g. intensive vs extensive crop farming).

Climate-land-use interactions shape tropical mountain biodiversity and ecosystem functions.

Agriculture and the exploitation of natural resources have transformed tropical mountain ecosystems across the world, and the consequences of these transformations for biodiversity and ecosystem functioning are largely unknown1-3. Conclusions that are derived from studies in non-mountainous areas are not suitable for predicting the effects of land-use changes on tropical mountains because the climatic environment rapidly changes with elevation, which may mitigate or amplify the effects of land use4,5. It is of key importance to understand how the interplay of climate and land use constrains biodiversity and ecosystem functions to determine the consequences of global change for mountain ecosystems. Here we show that the interacting effects of climate and land use reshape elevational trends in biodiversity and ecosystem functions on Africa's largest mountain, Mount Kilimanjaro (Tanzania). We find that increasing land-use intensity causes larger losses of plant and animal species richness in the arid lowlands than in humid submontane and montane zones. Increases in land-use intensity are associated with significant changes in the composition of plant, animal and microorganism communities; stronger modifications of plant and animal communities occur in arid and humid ecosystems, respectively. Temperature, precipitation and land use jointly modulate soil properties, nutrient turnover, greenhouse gas emissions, plant biomass and productivity, as well as animal interactions. Our data suggest that the response of ecosystem functions to land-use intensity depends strongly on climate; more-severe changes in ecosystem functioning occur in the arid lowlands and the cold montane zone. Interactions between climate and land use explained-on average-54% of the variation in species richness, species composition and ecosystem functions, whereas only 30% of variation was related to single drivers. Our study reveals that climate can modulate the effects of land use on biodiversity and ecosystem functioning, and points to a lowered resistance of ecosystems in climatically challenging environments to ongoing land-use changes in tropical mountainous regions.

Driving force analysis of landscape pattern changes in Honghu Wetland Nature Reserve in recent 40 years

利用Landsat系列遥感影像数据（1974、1979、1984、1990、1996、2001、2006、2009、2014和2017年）解译得到的土地利用/土地覆盖变化（LUCC）结合研究区44年的气温、降水量、水位等气象水文数据，构建LUCC经验统计模型和计算景观格局指数，探讨1974-2017年洪湖国家级自然保护区景观格局变化的主要驱动因素.研究结果表明：土地利用强度指数由1974年的207增加到2017年的249.36，人类开发利用湖滨带的程度增强，到2017年约有30%的自然湿地转化为坑塘、农田和滩地及建设用地.不同地表覆盖类型的景观格局指数均发生了较大变化，2000年以后湖滨带逐渐形成了以养殖为主的低矮围景观.总体上景观趋于破碎化、连通性降低、稳定性变弱.洪湖湿地自然保护区土地利用强度指数与景观格局综合指数呈较显著的正相关，两者的相关系数为0.84，土地利用强度增加则景观更加破碎、斑块之间的连接程度减弱、区域的景观聚集度下降和景观异质性增加.总体而言，洪湖湿地自然保护区受人为干扰影响明显，开展封湖育草自然恢复与建立植被恢复示范区相结合，构建自湖滨至湖心的梯度变化完整的湿生植被-挺水植被-漂浮植被-浮叶植被-沉水植被的水生植物群落，退耕还草、退垸还湖、修复湖滨带植被，大幅度提高洪湖的自净能力，增加其水生植物多样性，实现湿地的有效修复，改善其结构和功能，维系洪湖湿地生态系统的平衡.;This study took Honghu National Nature Reserve as an example to investigate the driving forces on Landscape pattern changes based on the land use and land change data of 1974, 1979,1984, 1990, 1996, 2001, 2006, 2009, 2014 and 2017, which were obtained from interpretation of Landsat images. Correlation analysis was adopted for finding characteristics of the interaction by combining with meteorological hydrological data such as temperature, precipitation and water stage. The results showed that:Land use intensity index risen from 207 at the begining of the study to 249.36 at the end of the study during the period of 1974-2017, these changes were more due to enlargement in the interference of human activities for land-use change. About 30% of the natural wetlands translated into ponds, farmland and bottomland and construction land by 2017. The landscape pattern indices of different types have changed greatly, the lakeside zone has formed a low enclosed ponds dominated by aquaculture after entering twenty-first Century. On the whole, landscape tended to be diversified, fragmented, reduced in connectivity and weakened in stability. The correlation coefficient between land use intensity index and the composite index of landscape pattern is 0.84, it shows that LUCC is very closely related to the landscape pattern. With the increase of land use intensity, the landscape is more fragmented, the degree of connectivity between patches is weakly, the landscape aggregation degree of the area is decreasing, and the landscape heterogeneity is increasing. In general, the Honghu Wetland Nature Reserve is affected obviously by human interference. The goal of maintaining the balance of Honghu wetland ecosystem is achieved through rational exploitation and utilization, returning farmland to grass and lake, restoring the vegetation of the lakeside zone, increasing the diversity of its aquatic plants, realizing the effective restoration of the wetland, improving its structure and function. A combination of the natural restoration of vegetation and the establishment of demonstration area of vegetation restorations is carried out, and the hygrophilous vegetation, emergent aquatic vegetation, floating vegetation, floating-leaved vegetation, and submerged vegetation, should be constructed from the lakeside to the heart of the lake.

Wind erosion enhanced by land use changes significantly reduces ecosystem carbon storage and carbon sequestration potentials in semiarid grasslands

AbstractWind erosion exerts a fundamental influence on the biotic and abiotic processes associated with ecosystem carbon (C) cycle. However, how wind erosion under different land use scenarios will affect ecosystem C balance and its capacity for future C sequestration is poorly quantified. Here, we simulated different intensities of land uses in Inner Mongolia: control, 50% of vegetation mowed (50 M), 100% vegetation mowed (100 M), and tillage (TI). We monitored abiotic C flux caused by wind erosion, net ecosystem exchange (NEE), and soil characteristics from 2013 to 2016. We found that the frequency of heavy wind exerts a fundamental control over the severity of soil erosion, and its interaction with precipitation and vegetation characteristics explained 69% of the variation in erosion intensity. With increases in land use intensity, the abiotic C flux induced by wind erosion increased rapidly, equivalent to 33%, 86%, 111%, and 183% of the NEE of natural steppe in the control, 50 M, 100 M, and TI sites, respectively. The erosion‐induced decrease in fine fraction soils led to 31%, 43%, and 85% permanent losses of C sequestration potential in the surface soil for 50 M, 100 M, and TI sites. Overall, our study demonstrates that the abiotic C flux associated with wind erosion is too large to be ignored. The loss of C‐enriched fine particles not only reduces the current ecosystem C content but also results in an irreversible loss of future soil C sequestration potential. These dynamic soil characteristics need to be considered when projecting future ecosystem C balance in aeolian landscapes.

Status of land use intensity in China and its impacts on land carrying capacity

Land use intensity quantifies the impacts of human activities on natural ecosystems, which have become the major driver of global environmental change, and thus it serves as an essential measurement for assessing land use sustainability. To date, land-change studies have mainly focused on changes in land cover and their effects on ecological processes, whereas land use intensity has not yet received the attention it deserves and for which spatially-explicit representation studies have only just begun. In this paper, according to the degree and reversibility of surface disturbance by human activities, there are four main classes of land use intensity: artificial land, semi-artificial land, semi-natural land, and natural land. These were further divided into 22 subclasses based on key indicators, such as human population density and the cropping intensity. Land use intensity map of China at a 1-km spatial resolution was obtained based on satellite images and statistical data. The area proportions of artificial land, semi-artificial land, semi-natural land, and natural land were 0.71%, 19.36%, 58.93%, and 21%, respectively. Human and economic carrying capacity increased with the increase of land use intensity. Artificial land supports 24.58% and 35.62% of the total population and GDP, using only 0.71% of the total land, while semi-artificial land supported 58.24% and 49.61% of human population and GDP with 19.36% of China’s total land area.

Spatial and seasonal variation of avian malaria infections in five different land use types within a Neotropical montane forest matrix

Seasonality as well as habitat destruction can alter host-parasite interactions. The montane cloud forest of Veracruz State in Mexico has been transformed into agro-ecosystems and cities. The aim of this study was to determine how ecological parameters of avian malaria parasites responded to five different land use types (i.e., well-preserved cloud forest, periurban forest, urban forest, coffee plantation, and cattle field) and to seasonality. We used microscopy and PCR methods to determine prevalence, parasitaemia, and aggregation of haemosporidians infecting the widespread chestnut-capped brush finch (Arremon brunneinucha). We performed PCA and cluster analyses to determine vegetation structure and similarity, and to investigate how relevant vegetation variables are associated with parasitological parameters. All haemosporidian infections in chestnut-capped brush finches belonged to Haemoproteus and Plasmodium species. Prevalence and parasitaemia of avian malaria were higher during the rainy season, while aggregation remained similar. Both prevalence and parasitaemia were higher in the urban forest. Prevalence was lower in the well-preserved cloud forest during the dry season. Parasitaemia was negatively associated to bush cover. Our results suggest that an increase in land use intensity reduces seasonal fluctuations in parasite transmission, and that infections are more frequent and more severe for birds inhabiting urban environments.

Biogeochemical indicators of peatland degradation – a case study of a temperate bog in northern Germany

Abstract. Organic soils in peatlands store a great proportion of the global soil carbon pool and can lose carbon via the atmosphere due to degradation. In Germany, most of the greenhouse gas (GHG) emissions from organic soils are attributed to sites managed as grassland. Here, we investigated a land use gradient from near-natural wetland (NW) to an extensively managed (GE) to an intensively managed grassland site (GI), all formed in the same bog complex in northern Germany. Vertical depth profiles of δ13C, δ15N, ash content, C / N ratio and bulk density as well as radiocarbon ages were studied to identify peat degradation and to calculate carbon loss. At all sites, including the near-natural site, δ13C depth profiles indicate aerobic decomposition in the upper horizons. Depth profiles of δ15N differed significantly between sites with increasing δ15N values in the top soil layers paralleling an increase in land use intensity owing to differences in peat decomposition and fertilizer application. At both grassland sites, the ash content peaked within the first centimetres. In the near-natural site, ash contents were highest in 10–60 cm depth. The ash profiles, not only at the managed grassland sites, but also at the near-natural site indicate that all sites were influenced by anthropogenic activities either currently or in the past, most likely due to drainage. Based on the enrichment of ash content and changes in bulk density, we calculated the total carbon loss from the sites since the peatland was influenced by anthropogenic activities. Carbon loss at the sites increased in the following order: NW < GE < GI. Radiocarbon ages of peat in the topsoil of GE and GI were hundreds of years, indicating the loss of younger peat material. In contrast, peat in the first centimetres of the NW was only a few decades old, indicating recent peat growth. It is likely that the NW site accumulates carbon today but was perturbed by anthropogenic activities in the past. Together, all biogeochemical parameters indicate a degradation of peat due to (i) conversion to grassland with historical drainage and (ii) land use intensification.

Lichen functional groups as ecological indicators of the effects of land-use in Mediterranean ecosystems

The effects of land-use on species and communities are usually studied by considering high-intensity land-use gradients. However, in many Mediterranean Europe areas, the traditional land-use regime is of low-intensity, including low-impact forestry practices and extensive livestock pasture. This low-intensity land-use is associated with ‘High Nature Value Farmlands’, which occupy more than 50% of total farmland area in Mediterranean areas. The objective of this work was to determine the effect of traditional low-intensity land-use on epiphytic lichen communities in Mediterranean cork-oak woodlands. We intend to investigate the value of lichen communities as early indicators of the effects of land-use changes. For that, lichens were sampled along a gradient of low-intensity land-use that included forestry and pasture activities. As lichen diversity variables we considered: (i) total species richness, (ii) total species frequency (LDV), and (iii) richness and frequency of functional groups dividing species according to their eutrophication-tolerance. We found an increase of total species richness with an increase of land-use intensity which is opposite to expectations and which was shown for first time in lichens. The increase in total species richness was due to an increase of the number of eutrophication tolerant species accompanied by the maintenance of the sensitive one when we analyzed the lichen-data at the functional response group level. These results fit with the intermediate disturbance hypothesis that predicts higher diversity under an intermediate disturbance due to the coexistence of species with contrasting ecological requirements. Traditionally managed cork-oak woodlands with low-intensity land-use can thus support a high diversity of lichen species. An important outcome was that we confirmed the importance of using ecological indicators based on functional-groups for monitoring changes in ecosystems and, since lichens responded to low levels of land-use intensity, we have also shown the possibility of using lichens as early indicators of the impacts of low intensity land-use.