Land Use Landscape Research Articles

Rosettes in a matrix: Predicting spatial variation in density of a large felid in a forest‐production mosaic

AbstractLarge carnivores are keystone for ecosystems and flagships for conservation efforts but face severe threats globally. Protected areas are vital for the conservation of these charismatic species along with a host of ecological processes. However, the extent and scope of protected areas for conservation of all threatened species is limited, especially in the global south. Considering larger landscapes that can be compatible with large carnivore conservation goals is an alternative approach to ensure their persistence. This study explores the potential of multi‐use landscapes for the persistence of a globally threatened large felid, the Indian leopard (Panthera pardus fusca). This study investigated the spatial variability of leopard densities across a land‐use gradient using spatially explicit capture‐recapture framework in a tea‐plantation‐dominated forest‐production landscape mosaic in the Duars region of northeastern India. While the density of leopards in this landscape was estimated to be 7.96 ± 1.56 (SE) per 100 km2, significant (p = .048, t = 2.02, df=61) differences in estimates were observed between tea‐plantations (11.53 ± 2.72 (SE) leopards per 100 km2) and the forested habitats (4.67 ± 2.07 (SE) per 100 km2). Densities between tea plantations and protected areas (a subset of the forested habitat) were found to be comparable (9.19 ± 4.55 (SE) per 100 km2). The study posits that conservation‐compatible land use in landscapes shared with people can host a higher density of adaptable large felids like leopard than forested areas and that conservation planning needs to move beyond the dominant PA‐centric paradigm. The study also reinforces the importance of multi‐use landscapes for wildlife conservation, especially for an adaptable large felid.

Spatio-temporal variations and multi-scenario simulation of landscape ecological risk in the drylands of the Yellow River Basin.

Over the past decades, the drylands of the Yellow River Basin (YRBD) have undergone profound changes in landscape patterns and ecological dynamics, significantly impacting regional sustainable development. To assess the spatio-temporal variations of ecological risk in the YRBD and provide guidance for sustainable regional development, we constructed a coupled Land Use-Landscape Ecological Risk Model-Geographical Detector-PLUS framework for the assessment, analysis, and simulation of dryland landscape ecological risk (LER). The main findings are as follows: (1) Between 2000 and 2020, the area of built-up land, forest, grassland, and water in the YRBD increased, while the area of unused land and cropland decreased. (2) LER exhibited significant spatial heterogeneity, dominated by Sub-low and Low risks. High risk areas were primarily located in the western Inner Mongolia Plateau, whereas Low risk areas were prevalent in the Loess Plateau, with an overall decline in risk levels over the 20years. (3) Water resources, ecological status, and human activities are the main driving factors affecting LER, with the impact of human activities becoming increasingly significant over the past 20years. (4) Under three development scenarios in 2030, the LER is projected to further decrease, although the impact of these scenarios varies across different research sub-regions. Notably, the Ecological Priority Scenario emerges as more effective in mitigating regional LER. (5) Developing precise land use policies tailored to regional characteristics, continuously implementing ecological restoration projects, strengthening water resource management, and enhancing monitoring capabilities are effective ways to reduce LER in the YRBD. This study systematically quantified the impact of different development scenarios on LER in the YRBD, revealing its spatio-temporal characteristics, and emphasized the importance of planning guidance, ecological restoration, and risk monitoring to align regional development with ecological protection. The findings provide scientific evidence for ecological protection and sustainable development in the YRBD and other drylands, offering valuable insights for global dryland ecological risk management.

Assessing Habitat Suitability: The Case of Black Rhino in the Ngorongoro Conservation Area

Efforts to identify suitable habitat for wildlife conservation are crucial for safeguarding biodiversity, facilitating management, and promoting sustainable coexistence between wildlife and communities. Our study focuses on identifying potential black rhino (Diceros bicornis) habitat within the Ngorongoro Conservation Area (NCA), Tanzania, across wet and dry seasons. To achieve this, we used remote sensing data with and without field data. We employed a comprehensive approach integrating Sentinel-2 and PlanetScope images, vegetation indices, and human activity data. We employed machine learning recursive feature elimination (RFE) and random forest (RF) algorithms to identify the most relevant features that contribute to habitat suitability prediction. Approximately 36% of the NCA is suitable for black rhinos throughout the year; however, there are seasonal shifts in habitat suitability. Anthropogenic factors increase land degradation and limit habitat suitability, but this depends on the season. This study found a higher influence of human-related factors during the wet season, with suitable habitat covering 53.6% of the NCA. In the dry season, browse availability decreases and rhinos are forced to become less selective of the areas where they move to fulfil their nutritional requirements, with anthropogenic pressures becoming less important. Furthermore, our study identified specific areas within the NCA that consistently offer suitable habitat across wet and dry seasons. These areas, situated between Olmoti and the Crater, exhibit minimal disturbance from human activities, presenting favourable conditions for rhinos. Although the Oldupai Gorge only has small suitable patches, it used to sustain a large population of rhinos in the 1960s. Land cover changes seem to have decreased the suitability of the Gorge. This study highlights the importance of combining field data with remotely sensed data. Remote sensing-based assessments rely on the importance of vegetation covers as a proxy for habitat and often overlook crucial field variables such as shelter or breeding locations. Overall, our study sheds light on the imperative of identifying suitable habitat for black rhinos within the NCA and underscores the urgency of intensified conservation efforts. Our findings underscore the need for adaptive conservation strategies to reverse land degradation and safeguard black rhino populations in this dynamic multiple land-use landscape as environmental and anthropogenic pressures evolve.

Progress in Ecosystem Services Research Under the Evolution of Land Use Landscape Patterns

Land use change (LUUC) is the most intuitive reflection of human activities and a key driver causing changes in ecosystem types and landscape pattern evolution [162]. Changes in land use patterns, structure, composition, intensity, and spatial patterns due to natural and anthropogenic factors affect ecosystem processes such as species movement, soil erosion, and patterns of biodiversity distribution, which in turn affect a wide range of ecosystem services, such as food provisioning, flood storage, soil retention, and soil and water conservation, and ultimately affect human well-being. Most studies have shown that changes in land use landscape patterns affect ecosystem services through multiple pathways, including changes in biodiversity, ecosystem processes and habitats. Land use change and ecosystem services have a reciprocal relationship, and the evolution of land use landscape pattern will directly affect or change the structure and function of ecosystems, which ultimately affects ecosystem services, while the results of the ecosystem services assessment can also provide a scientific basis for the formulation of relevant policies. Therefore, understanding the relationship between the evolution of land-use landscape patterns and the response of ecosystem services can not only clearly reveal the process of land-use landscape evolution, but also more accurately assess the function of ecosystem services, which can promote the scientific formulation and effective implementation of relevant planning and protection policies.

Analysis of spatiotemporal variation and relationship to land use – landscape pattern of PM2.5 and O3 in typical arid zone

Land use – landscape pattern act as pollutant sources carries for PM2.5 and ozone, understanding the relationship between them is valuable for the management of atmospheric environment. In this investigation, we examined the spatiotemporal distribution characteristics of PM2.5 and ozone in Xinjiang during 2000 ∼ 2022. Meanwhile, we employed the random forest model under optimal model selection to explore the response of the land use - landscape pattern to the pollutants. The conclusions suggested: (1) PM2.5 in 94.82% of the area showed a significant decrease, with high levels concentrated in the Tarim Basin, Turpan-Hami Basin. Ozone demonstrated a remarkable upward trend in 99.30% of the region, showing high levels in the Tarim Basin and the northern Xinjiang. (2) Upon comparison with the univariate and stepwise linear regression models, random forest model holds significant practical value in quantifying the impact of pollutants on land use-landscapes. (3) In the land use – landscape pattern, the complexity and aggregation of cropland and water, the degree of connectivity in barren and impervious, the diversity and complexity of forest, and the degree of aggregation of grasslands all strongly impact PM2.5. For ozone concentrations, the index characterizing the degree of patchy aggregation is overwhelmingly dominant.

Changes in the land-use landscape pattern and ecological network of Xuzhou planning area

Ongoing rapid urbanization has triggered significant changes in land use, rendering landscape patterns adversely impacted and certain habitat patches degraded. Ecological networks have consequently contracted overall. As such, an investigation into how land-use landscape patterns and ecological networks change over time and space is of major significance for ecological restoration and regional sustainability. Taking Xuzhou Planning Area as a case study, we examined spatiotemporal changes and features of the landscape pattern by employing the land-use change degree, the land-use transition matrix, and quantified landscape pattern indices. An ecological network analysis, which studies the changes in network connectivity and robustness, as well as their causes and contributors, was undertaken to probe into the features and trends of spatiotemporal changes in the land-use landscape pattern and ecological network amid expeditious urbanization. Analysis results unveiled the following: (1) From 1985 to 2020, there was a decline in the area of farmland, forest, and grassland, accompanied by an increase in land for construction, water bodies, and unused land. The southwestern research area witnessed farmland substantially give way to land for construction for this period, and the most dramatic change in land use occurred between 2000 and 2010. (2) The area of dominant patches in the research area shrank, along with more fragmented, complex landscapes. The land for construction was emerging as the dominant landscape by area, whereas patches of farmland, forest, grassland, and water bodies became less connected. (3) The ecological network was densely linked in the northeast, with sparser connections in the southwest. Spatial shrinkage was observed in the research area’s southwestern and central ecological corridors. Overall, the number of ecological sources and corridors rose and subsequently dropped before a rebound. (4) The ecological network grew more connected and robust from 1985 through 1990, as portions of farmland were converted into water bodies, which led to an increase in ecological sources. Given a reduction in ecological sources and corridors in the southwestern and central regions between 1990 and 2010, network connectivity and robustness declined, which was reversed from 2010 onward with the addition of two ecological sources—Pan’an Lake and Dugong Lake. With an optimal ecological network in 1990, however, it deteriorated significantly by 2010. The research area saw the minimum value of its network connectivity indices of network stability index (α), evenness index (β), and connectivity index (γ), in 2010, when its ecological network was highly fragmented and vulnerable, attributing to a strong contrast between the maximal connected subgraph’s relative size and connectivity robustness. The research findings can lay scientific groundwork for addressing ecological issues, restoring landscape patterns, and developing ecological networks amid urbanization.

Landscapes drive the dispersal of Monochamus alternatus, vector of the pinewood nematode, revealed by whole-genome resequencing

Pine wilt disease (PWD), Bursaphelenchus xylophilus, is an extremely threatening invasion forest disease throughout the world, especially in Asia. B. xylophilus is spread in Asia by vector beetles of Monochamus alternatus, which has long no effective control method. Understanding of landscape effects on the dispersal and outbreaks of forest pests is crucial to establishing effective ecological control strategies. Here, we analyzed the samples of M. alternatus collected in a fine-scale in order to estimate the effects of landscape types on the genetic structure and dispersal of M. alternatus. The landscapes included the geographical scales, forest types and land uses. The individuals of M. alternatus were genotyped by using whole-genome resequencing. Population genetic structures were clearly differentiated at the range of 250 kms, suggesting the intermediate scale is an effective barrier against natural dispersal of M. alternatus. We used the least-cost distances, least-cost transect analysis, and distance-based redundancy analysis to estimate the effects of forest types and land uses within the fine scales. The results showed that the gene flow and genetic diversity were positively correlated with host and mixed forests, whereas negatively with non-host forests. Among land-use landscapes, the roads had the positive effect on gene flow and genetic diversity but farmland and urban uses had negative effects. This highlights that human-mediated transport via roads was likely to be the main factor leading to the long-distance invasion of M. alternatus, whereas non-host landscapes could suppress the spread of this species. These findings may be useful to control the PWD dispersed by M. alternatus.

Changes of the spatial and temporal characteristics of land-use landscape patterns using multi-temporal Landsat satellite data: A case study of Zhoushan Island, China

The research on the changes of the spatial and temporal characteristics of land-use landscape patterns can deeply insight the movement of the Earth's surface by human activities, natural factors, and biological factors in time and space. This paper uses Landsat data for eight periods from 1984 to 2020 to explore the spatial and temporal characteristics of the land-use landscape pattern. First, the remotely sensed data were pre-processed. Then, the supervised classification was performed using the maximum likelihood-based method to obtain the information about the land-use and land cover changes in the study area, and an accuracy evaluation was carried out. Finally, the analysis of gravity center movement for the land-use type landscape pattern was carried out. The research results show that the construction land increased from 18.19 km2 in 1984 to 115.97 km2 in 2020. The forest land decreased from 205.72 km2 in 1984 to 194.39 km2 in 2020. The water bodies increased from 5.51 km2 in 1984 to 12.60 km2 in 2020. The mudflats decreased from 19.24 km2 in 1984 to 13.73 km2 in 2020. The cropland/grassland decreased from 210.98 km2 in 1984 to 203.87 km2 in 2020. The bare land decreased from 19.05 km2 in 1984 to 6.09 km2 in 2020. The average annual change area of the construction land, forest land, water bodies, mudflats, cropland/grassland, and bare land were 2.72 km2, −0.31 km2, 0.20 km2, −0.15 km2, −0.20 km2, and −0.36 km2, respectively. The average annual change rates of the construction land, forest land, water bodies, mudflats, cropland/grassland, and bare land were 5.28%, −0.16%, 2.33%, −0.93%, −0.10%, and −3.12%, respectively. The moving distance of gravity center of the construction land, forest land, water bodies, mudflats, cropland/grassland, and bare land were 2.98 km, 0.20 km, 2.38 km, 3.32 km, 0.98 km, and 8.39 km, respectively. The spatial distribution continuity and regional coordination of the construction land was significantly enhanced. The continuity of the spatial distribution of the forest land was continuously maintained at a high level. The spatial distribution of the water bodies was highly discrete. The continuity of the spatial distribution of the mudflats decreased. The spatial distribution and morphological features of the cropland/grassland tended to be discrete. The spatial continuity of the bare land increased. This research provides valuable dataset and gives insights for regional sustainable development planning and ecological assessment in Zhoushan Island, China.

Geoinformation analysis of natural potential of agricultural lands in samara region

The work was done in order to improve the territorial organization of agricultural production in the context of the implementation of the adaptive landscape land use strategy based on the assessment and analysis of the spatial and temporal structure of the natural agricultural potential (NAP) of the territory. The results of dynamic statistical simulation of normative crops productivity and land bonitet assessment of administrative districts of the Samara region are used. GIS analysis of the results and mesoscale comprehensive assessed zoning of the territory is applied. As a result, seven mesozones were allocated in the region with assure accordance of the bonitet scales and crop productivity formation factors (correlation coefficients with many indicators 0.7-0.9), which include relevant assessment areas with the most uniform conditions (coefficient of variation of indicators within 10%). The zoning is done in the contours of the administrative division of the territory and forms the geographic basis for resolving the agro-production issues of the respective management and land assessment objects in the framework of the formation of the adaptive landscape land use system.

Carbon Isotope Ratios of Plant n-Alkanes and Microstratigraphy Analyses of Dung Accumulations in a Pastoral Nomadic Winter Campsite (Eastern Mongolia)

ABSTRACTLivestock fecal remains provide an important source of information on past animal husbandry systems and dung use. A combined micromorphological and biomolecular investigation of dung deposits brings new perspectives into past landscape land use and animal husbandry strategies by providing seasonal-scale information on livestock dietary intake as well as intensity of dung deposition in penning spaces. We conducted microstratigraphic analyses and compound-specific carbon stable isotope analysis of plant n-alkanes of dung deposits associated with pastoral nomadic winter campsites in Mongolia, in order to explore the floral origin of graze ingested by livestock and evaluate its potential biomolecular signatures. Preliminary results show that δ13C values of plant n-alkanes were unusually depleted when compared to carbon isotope values of plant n-alkanes in soil control samples recovered from landscapes with minimal anthropic activity. We highlight the importance of multi-proxy ethnoarcheological studies in identifying biomarkers that convey information on pastoralist animal exploitation practices.

Effects of land use and landscape pattern on PM2.5 in Yangtze River Delta, China

Land cover-landscape pattern affects the atmospheric environment directly or indirectly, and the understanding of the atmospheric environment response to land cover - landscape pattern is of great significance to the maintenance and improvement of ecological environment. In this paper, such 9 landscape metrics as PLAND, PD, LPI, ED, MPS, AWMSI, CONTAG, SHDI and SHEI were selected by remote sensing inversion of PM2.5 data and land use data in long time series. The correlation analysis and multiple stepwise regression analysis were also used to analyze the effect of land use and landscape pattern on PM2.5 in Yangtze River Delta. The results showed that: (1) PM2.5 concentration was increasing in Yangtze River Delta from 1998 to 2015; (2) PM2.5 concentration was negatively correlated with the forest land and grassland, while positively correlated with the urban construction land; (3) At the level of landscape type, the urban construction land, water body and farm land PLAND, LPI, ED, MPS, AWMSI were positively correlated, the urban construction land and water body PD were positively correlated with PM2.5, the farm land PD was negatively correlated with PM2.5, and the forest land and grassland PLAND, PD, LPI, ED, MPS and AWMSI were negatively correlated with PM2.5. (4) In the integral landscape of land use, AWMSI was negatively correlated with PM2.5 concentration. It is of great significance to control PM2.5 pollution from the perspective of land use planning and contributed to an estimation methods of PM2.5 concentrations using land use type and land use landscape metrics in the absence of missing PM2.5 monitoring data.

典型喀斯特地区石漠化景观格局对土地利用变化的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 典型喀斯特地区石漠化景观格局对土地利用变化的响应 DOI: 10.5846/stxb201807231576 作者: 作者单位: 贵州师范大学,中国科学院地球化学研究所,贵州师范大学地理与环境科学学院,中国科学院地球化学研究所,贵州师范大学,中国科学院地球化学研究所,贵州师范大学,中国科学院地球化学研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划（2016YFC0502102）；中国科学院科技服务网络计划（KFJ-STS-ZDTP-036）；"西部之光"人才培养计划（A类）（〔2018〕X）；贵州省科技计划（2017-2966） Response of landscape pattern of karst rocky desertification to land-use change in a typical karst area Author: Affiliation: School of Geography and Environmental Sciences,Institute of Geochemistry, Chinese Academy of Sciences,,Institute of Geochemistry, Chinese Academy of Sciences，Guizhou normal university,Institute of Geochemistry, Chinese Academy of Sciences，Guizhou normal university,Institute of Geochemistry, Chinese Academy of Sciences Fund Project: This research work was supported jointly by national key research program of China (No. 2016YFC0502102 & 2016YFC0502300), 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:土地利用是人类活动最基本的表现形式，探讨石漠化与土地利用变化之间的响应关系，对于石漠化治理和区域的可持续发展是非常重要的。基于贵州道真县2005年、2015年LANDSAT和石漠化数据，再利用ENVI 5.3进行监督分类，将道真县土地利用分为8种类型。通过景观格局空间分析技术和3S技术，对道真县土地利用时空演变和石漠化景观格局进行综合分析，结果表明：（1）2005-2015年间，道真县建设用地和灌木林地面积增加，大部分灌木林地由水田和旱地转化而来，其面积增加了7.51%，建设用地增加了1.30%。（2）近10年间，研究区石漠化等级间的转移表现为轻、中、重度转化为潜在石漠化，其斑块转移面积分别为11.26、38.79、2.71 km2，表明研究区石漠化景观得到了恢复，低等级石漠化斑块面积增加，降低了原有高等级石漠化斑块的优势度。（3）2005-2015年间道真县土地利用和石漠化景观格局，多样性指数分别下降了0.6434和2.4309，均匀度指数各减少了0.0552和0.5436，分维度指数各提高了0.0061和0.0801，蔓延度指数各增加0.1751、25.5396和聚合度指数分别增加1.8688和2.9112，景观形状指数分别减少0.9812和4.536，石漠化景观格局的变化对应土地利用景观格局指数的变化，随着人们土地利用方式的改变，石漠化也发生相应的改变。通过该研究的进行，有助于提高人们对石漠化和土地利用景观格局的认识，基于景观生态学背景对石漠化治理成效进行评估，为之后的石漠化治理工作的进行及研究提供了参考。 Abstract:Land-use is the most basic manifestation of human activities. It is essential to explore the response relationship between Karst Rocky Desertification (KRD) and land-use change for the control of KRD and regional sustainable development. Based on LANDSAT and KRD data from 2005 and 2015 in Daozhen County of Guizhou Province, the land-use in Daozhen County was classified into 8 types by ENVI5.3. The spatial and temporal evolution of land use and landscape pattern of KRD in Daozhen County were analyzed using landscape pattern spatial analysis and 3S technology. The results showed that:(1) During 2005-2015, the area of construction land and shrubbery land increased; most shrubbery land was transformed from paddy fields and dry land, and the area increased by 7.51%. Construction land increased by 1.30%. (2) Over the 10 study years, the metastasis between the rocky desertification grades in the study area exhibited light, medium, and severe conversion into potential rocky desertification. The plaque transfer areas were 11.26 km2, 38.79 km2, and 2.71 km2, respectively, indicating a rocky desertification landscape in the study area. The land has been restored, and the area of low-grade rocky desertification plaques has increased, which reduced the superiority of the original high-grade rocky desertification patches; (3) Landscape patterns of land-use and KRD in Daozhen County decreased by 0.6434 and 2.4309 in 2005 and 2015. The evenness index decreased by 0.0552 and 0.5436, the fractal dimension index increased by 0.0061 and 0.0801, the contagion index increased by 0.1751, 25.5396, and the aggregation index increased by 1.8688 and 2.9112, respectively, and the landscape shape index decreased by 0.9812 and 4.536, respectively. The change in the landscape pattern index of land use corresponded to the change in the landscape pattern of KRD. With change of land-use patterns, the contagion index increased by 0.1751, 25.5396, and 2.9112, respectively. The KRD changed accordingly. This study will help to improve people's understanding of KRD and land-use landscape patterns. Based on the landscape ecology background, the effect of KRD control was evaluated, which will provide a reference for future research regarding KRD control. 参考文献 相似文献 引证文献

Health centre visits among the elderly with chronic ailments: Evidence from the Kanchanaburi Demographic Surveillance System, 2004, Thailand

ABSTRACTThis study deployed statistical and spatial (GIS) analyses to test the effects of geographic, demographic and occupational factors in predicting health centre visits among the elderly (≥60 years) with chronic ailments in Kanchanaburi Province, western Thailand. Datasets from the Kanchanaburi Demographic Surveillance System (2004 baseline survey and a 2006 project follow-up) comprised five land-use landscape and occupational strata: urban/semi-urban (industrial), rice field, plantation crop, upland and mixed economy. Travel distance to the nearest health centre was calculated following transportation routes and the GPS coordinates of individual home locations, and the number of healthcare visits under the national free universal coverage (UC) scheme reported for the previous year was used as a dependent variable in regressions. Broadly, the study found that distance was not a significant predictor of the rate of elderly health centres visits for those with co-residing spouses and/or adult children (77% of sample), and for the elderly still working (48% of the sample) who were the least likely to access healthcare. Owning motorised vehicles did not encourage visits, which also varied by land-use and occupational strata.

The Whole Story. Bridging the Gap between Landscape-archaeological Data from Drylands and Wetlands

Detailed historical reconstructions require high-quality data. In the traditionally densely settled higher and drier Pleistocene sandy areas (‘drylands’) of the North European Plain (the European aeolian sand belt) and comparable regions elsewhere evidence-based reconstructions are hampered by poor preservation of archaeological remains and archaeologically relevant deposits. This problem can be partially solved by combining, on a microregional level, dryland data with data from nearby wetland pockets (‘wetlands’),in particular stream valleys. This asks for an integrated and systematic inventory of all available data. For this purpose an instrument was developed: the Landscape-Land use Diagram (LLAND). Because data from dry and wet contexts are to some degree supplementary, integrated analysis is essential for obtaining information on the full range of economic and ritual practices. This is demonstrated by research carried out in the valley of the small river Regge (the Netherlands), the results of which are being treated as a stratified landscape-archaeological sample. This paper does not focus on cultural interpretation but on methodology, specifically the potential of data and the benefits of an integrated approach.

Scales of impact: Settlement history and landscape change in the Gordion Region, central Anatolia

The expansion of agriculture in the Near East during the middle Holocene significantly altered the physical landscape. However, the relationship between the scale of agriculture and the magnitude and timing of the environmental impacts is not well known. The Gordion Regional Survey provides a novel dataset to compare settlement density during archaeological periods to rates of environmental disruption. Sediment samples from alluvial cores directly date the environmental disruption, which can be matched to period-specific settlement intensities in the watershed as constructed from archaeological survey ceramics. Degradation rates rose sharply within a millennium of the earliest Chalcolithic occupation. Early Bronze Age (EBA) land use induced the greatest rates of environmental degradation, although settlement density was relatively low on the landscape. The degradation rate subsequently decreased to one-third its early peak by the Iron Age, even as settlement intensity climbed. This trajectory reveals how complex interaction effects can amplify or subdue the responses of the landscape–land use system. Prior to settlement, landscape soil reservoirs were highly vulnerable, easily tipped by early agricultural expansion. Subsequent reduced rates of erosion are tied both to changes in sociopolitical organization and to depletion of the vulnerable soil supply.

Coherence and fragmentation of landscape patterns as characterized by correlograms: A case study of Estonia

The homogenization and fragmentation of landscapes caused by intensive management is an increasing problem worldwide. Therefore, there is need for development of methods that help to improve sustainable management and maintain the identity of landscapes. We proposed that landscape coherence is the similarity between soil pattern (potential landscape) and land use intensity (actual landscape), which may be investigated by means of correlograms. We studied the spatial autocorrelation (Moran's I) of raster format soil maps and land use maps (1:10,000; 10 m pixel size) in 35 study areas representing all landscape regions in Estonia. Various soil characteristics were taken into consideration in compiling the scale of contrast of 17 soil groups, whereas 19 land use types were ordered according to the intensity of human influence. We use a simple characteristic based on correlograms: a half-value distance lag, h I = 0.5, a distance where Moran's I equals 0.5. According to the value of h I = 0.5, in till-covered areas, the landscape structure is more fragmented in uplands than in lowlands. We found two study areas where the soil pattern was coherent with land use intensity, and detected a tendency that human influence makes the landscape pattern in uplands more homogeneous and in lowlands more heterogeneous, whereas the similarity between landscape patterns in lowlands and uplands is increasing due to human influence. This concept of coherence helps planners and decision makers to determine the optimal land use in landscapes by either reducing or increasing the fragmentation of the landscape pattern.

Fitness costs and benefits of novel herbicide tolerance in a noxious weed.

Glyphosate, the active ingredient in the herbicide RoundUp, has increased dramatically in use over the past decade and constitutes a potent anthropogenic source of selection. In the southeastern United States, weedy morning glories have begun to develop tolerance to glyphosate, representing a unique opportunity to examine the evolutionary genetics of a novel trait. We found genetic variation for tolerance, indicating the potential for the population to respond to selection by glyphosate. However, the following significant evolutionary constraint exists: in the absence of glyphosate, tolerant genotypes produced fewer seeds than susceptible genotypes. The combination of strong positive directional selection in the presence of glyphosate and strong negative directional selection in its absence may indicate that the selective landscape of land use could drive the evolutionary trajectory of glyphosate tolerance. Understanding these evolutionary forces is imperative for devising comprehensive management strategies to help slow the rate of the evolution of tolerance.