Historical Land Use Change Research Articles

Bilberry Expansion in the Changing Subalpine Belt.

Bilberry (Vaccinium myrtillus L.) expansion in subalpine and alpine ecosystems is increasing due to climate change and reduced land management. This review examines bilberry traits, environmental responses, and ecosystem impacts. As a stress-tolerant chamaephyte, bilberry thrives in acidic, nutrient-poor soils across various habitats. It propagates effectively through rhizomes and demonstrates a phalanx growth form. Bilberry's growth and distribution are influenced by elevation, soil structure, pH, water availability, and nitrogen content. Mycorrhizal associations play a crucial role in nutrient uptake. The species modifies the microclimate, facilitates litter accumulation, and influences soil microbial communities, affecting nutrient turnover and biodiversity. Bilberry shows moderate tolerance to herbivory and frost, with the ability to recover through rapid emergence of new ramets. However, severe or repeated disturbances can significantly impact its abundance and reproductive success. Climate warming and atmospheric nitrogen deposition have accelerated bilberry growth in treeline ecotones. The management of bilberry expansion requires a nuanced approach, considering its resilience, historical land-use changes, and environmental factors. The goal should be to limit, not eliminate, bilberry, as it is a natural part of subalpine communities. Long-term comparative monitoring and experimental manipulation are necessary for effective management strategies.

The centennial legacy of land-use change on organic carbon stocks of German agricultural soils.

Converting natural vegetation for agriculture has resulted in the loss of approximately 5% of the current global terrestrial soil organic carbon (SOC) stock to the atmosphere. Increasing the agricultural area under grassland may reverse some of these losses, but the effectiveness of such a strategy is limited by how quickly SOC recovers after conversion from cropland. Using soil data and extensive land-use histories gathered during the national German agricultural soil inventory, this study aims to answer three questions regarding agricultural land-use change (LUC): (i) how do SOC stocks change with depth following LUC; (ii) how long does it take to reach SOC equilibrium after LUC; and (iii) what is the legacy effect of historic LUC on present day SOC dynamics? By using a novel approach that substitutes space for time and accounts for differences in site properties using propensity score balancing, we determined that sites that were converted from cropland to grassland reached a SOC equilibrium level 47.3% (95% confidence interval (CI): 43.4% to 49.5%) above permanent cropland levels 83 years (95% CI: 79 to 90 years) after conversion. Meanwhile, sites converted from grassland to cropland reached a SOC equilibrium level -33.6% (95% CI: -34.1% to -33.5%) below permanent grassland levels after 180 years (95% CI: 151 to 223 years). We estimate that, over the past century, today's German agricultural soils (16.6 million ha) have gained about 40 million Mg C. Furthermore, croplands with historic LUC from grassland are losing SOC by -0.26 Mg ha-1 year-1 (10% of agricultural land) while grasslands historically converted from cropland are gaining SOC by 0.27 Mg ha-1 year-1 (18% of agricultural land). This study shows that even long-standing temperate agricultural sites likely have ongoing SOC change as a result of historical LUC.

Assessing inconsistencies in historical land-use reconstructions for Africa at 1800

Reconstructing historical land-use and land-cover change (LULCC) inevitably involves interpolation across regions for which there is limited data to support reconstructions. Here, we evaluate the extent to which the global land-use model HYDE v3.2.1 reflects historical land use in sub-Saharan Africa (including Madagascar) when compared to archaeological and historical reconstructions. Both the HYDE models and Widgren’s archaeological and historical reconstructions estimate that agriculture was widely scattered across sub-Saharan Africa in 1800 CE. However, in steep terrain, at slopes greater than 10°, the HYDE model estimated 0% cropland allocation while archaeological and historical observations suggest intensive, mixed and extensive farming was common in these areas. In addition, while HYDE allocates farmland primarily into high-quality soils, archaeological reconstructions suggest that intensive farming occurred across a wide range of soil qualities. Gaps in our knowledge of cropland distribution have significant impacts on models of biodiversity change since understanding biodiversity in the Anthropocene is reliant on our understanding of past land-use changes. While HYDE’s mismatches are known, the research presented here provides an important resource in identifying where these allocation rules fail. These mismatches in global land-use models such as HYDE might also be replicated for other regions of the world, such as South America. These mismatches also need to be accounted for when generating model projections that use historical land-use models to impute present and future trends in land-use, climate and biodiversity change. Localised archaeological and historical data can therefore be used to support historical global land-use reconstructions for Africa and other regions across the world.

Tourism Investment and Land Use Change in the Northern Piedmont of the Western High Atlas (1989-2022)

This study aimed to investigate the profound influence of tourism investment on the Northern Piedmont of the western High Atlas over 34 years in response to the escalating global trend of tourism-driven land-use changes, particularly in the Marrakesh region. In this context, the driving forces behind the significant transformation of agricultural land and bare soils into tourism-driven investments were evaluated as well as the critical role of accessibility in shaping spatial shifts. The method used high-resolution (10 m) satellite images from Spot 1 (1989), Spot 5 (2003 & 2010), and Sentinel 2 (2022) through remote sensing methods to investigate the historical land-use changes over 34 years. The results showed significant transformations in land-use based on the correlation between improved transportation infrastructure and the growth of tourism ventures, underscoring the role of roads and facilities as catalysts. The analysis suggested the need for reflection on the consequences of unregulated tourism growth, aiming to balance economic benefits with environmental and socio-cultural challenges in sensitive regions. Although tourism significantly contributed to economic development and employment opportunities, it also posed risks when not managed prudently. This underscored the need to strike a harmonious equilibrium between economic prosperity as well as preserving the unique natural beauty and cultural heritage of the region. The insights provided in this analysis had broader implications for responsible planning and management of tourism development in sensitive ecological and cultural regions. In conclusion, a thoughtful and sustainable approach was needed to safeguard the delicate balance between economic prosperity and environmental preservation.

Alternative vegetation trajectories through passive habitat rewilding: opposite effects for animal conservation

ContextPassive habitat rewilding after rural abandonment can affect wildlife differently depending on the type of habitats that it generates.ObjectiveEvaluate and compare the effects of two alternative vegetation trajectories that occur through passive habitat rewilding in Mediterranean ecotone areas (crop-scrub and crop-pine forest transitions) on the long-term population dynamics of animal species.MethodsWe used the spur-thighed tortoise (Testudo graeca), a characteristic long-lived species of cultural landscapes, as study species. We applied a spatially explicit and individual-based model (STEPLAND) to simulate the movement and demographic processes in a long-term period, by comparing an “impact scenario” (i.e., historical land-use changes) to a “control scenario” (no land-use changes).ResultsThe two landscape scenarios resulted in different population trends. In the crop-scrub scenarios (control and impact), population densities increased similarly over time. However, the crop-pine forest scenario negatively affected population density throughout the simulation period, and showed a time-lag response of three decades. The extinction risk was 55% with a time-lag response of approximately 110 years.ConclusionsOur study highlights the need to analyse the legacy effects on long-lived ectotherms, using them as a proxy to understand the future effects of dynamic landscapes created by “passive habitat rewilding”. Our results showed how traditional agriculture in Mediterranean ecotone areas may generate “ecotone effects” (i.e. increase in demographical parameters), but also population extinction on long-lived ectotherms. Therefore, we consider it relevant to maintain traditional agricultural areas in Mediterranean landscapes, especially in ecotone areas associated with pine forests (generating mosaics with open habitats).

Hydroclimatic Vulnerability of Wetlands to Upwind Land Use Changes

AbstractDespite their importance, wetland ecosystems protected by the Ramsar Convention are under pressure from climate change and human activities. These drivers are altering water availability in these wetlands, changing water levels or surface water extent, in some cases, beyond historical variability. Attribution of the effects of human and climate activities is usually focused on changes within the wetlands or their upstream surface and groundwater inputs. However, the reliance of wetland water availability on upwind atmospheric moisture supply is less understood. Here, we assess the vulnerability of 40 Ramsar wetlands to precipitation changes caused by land use and hydroclimatic change occurring in their upwind moisture‐supplying regions. We use moisture flows from a Lagrangian tracking model, atmospheric reanalysis data, and historical land use change (LUC) data to assess and quantify these changes. Our analyses show that historical LUC has decreased precipitation and terrestrial moisture recycling in most wetland hydrological basins, decreasing surface water availability (precipitation minus evaporation). The most substantial effects on wetland water availability occurred in the tropic subtropical regions of Central Europe and Asia. Overall, we found wetlands in Central Asia and South America to be the most vulnerable by a combination of LUC‐driven effects on runoff, high terrestrial precipitation recycling, and recent decreases in surface water availability. This study stresses the need to incorporate upwind effects of land use changes in the restoration, management, and conservation of the world's wetlands.

Spatiotemporal Characteristics of Land Cover Change in the Yellow River Basin over the Past Millennium

Investigating the ecological and environmental impacts stemming from historical land use and land cover change (LUCC) holds paramount importance in systematically comprehending the fundamental human-land relationship, a pivotal focus within geographical research. The Yellow River Basin (YRB), often referred to as the cradle of Chinese civilization, ranks as the fifth-largest river basin globally. Early inhabitants made significant alterations to the landscape, resulting in substantial damage to natural vegetation, giving rise to prominent regional ecological challenges. By now, the examination of historical LUCC in the YRB over the past millennium remains in the qualitative research stage, primarily due to the limited availability of high-confidence gridded historical LUCC data. This study aims to advance the current historical LUCC research in the YRB from primarily qualitative analysis to an exploration incorporating timing, positioning, and quantification. Based on reconstructed historical cropland, forest, and grassland grid data of 10 km × 10 km from 1000 AD to 2000 AD, the degree of cropland development and the depletion of forests and grasslands were calculated, respectively. Then, the kernel density method was employed for spatiotemporal analysis and interpretation of dynamic changes in land cover. Subsequently, a cartographic visualization depicting the migration trajectories of the land cover gravity centers was generated, allowing for an assessment of the distance and direction of the centroids’ movement of cropland, forest, and grassland. The results indicate that the cropland coverage in the YRB escalated from the initial 11.65% to 29.97%, while the forest and grassland coverage dropped from 63.36% to 44.49%. The distribution of cultivated land continually expanded outward from the southeast of the Loess Plateau and the southwest of the North China Plain. All three types of land cover experienced a westward shift in their gravity centers between 1000 and 2000 AD. Besides the population growth and technological advancements, the regime shifts induced by wars, along with land use policies in distinct periods, always served as the predominant factors influencing the conversion between different land covers. This research will present a paradigmatic regional case study contributing to the investigation of historical changes in land use and land cover. Additionally, it will offer historical perspectives beneficial for the advancement of China’s objectives in “Ecological Conservation and High-Quality Development of the Yellow River Basin”.

Impact of Land-Use Changes on Climate Change Mitigation Goals: The Case of Lithuania

The land-use, land-use change and forestry (LULUCF) sector is receiving increasing attention in climate change mitigation and greenhouse gas (GHG) emission offsetting. The sector itself and measures applied to mobilize this sector in order to tackle climate change are dominant in nationally determined contributions under the Paris Agreement as well as in national strategies, as in the case of Lithuania. Lithuania has set the goal of becoming a carbon-neutral country in 2050, reducing GHGs by 80% compared to 1990 and offsetting the remaining 20% through the LULUCF sector. Therefore, this paper aims at analyzing historical land-use changes in 1990–2021, as reported for the United Nations Framework Convention on Climate Change (UNFCCC) secretariat, and LULUCF’s potential to achieve climate change mitigation goals, taking into account different land-use change scenarios (business as usual, forest development, forest development + additional measures and forest land 40% + additional measures) for 2030 and 2050 in Lithuania. The scenarios are based on historical and potential future policy-based land-use changes. Projections of GHG emissions/removals for different scenarios are prepared according to the Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories (2006) by the Intergovernmental Panel on Climate Change (IPCC). The results indicate that land-use changes over the period 1990–2021 remained rather stable, with some increases in forest area and grassland at the expense of cropland. The whole LULUCF sector acted as a carbon sink in most cases, forests being a key category for removal. However, reaching climate neutrality in 2050 might be challenging, as the goal to offset 20% of remaining GHG emission compared to 1990 through LULUCF would not be met in any of the scenarios analyzed, even the scenario of maximal forest-area development and additional measures. Considering the high historical GHG-removal fluctuations and the uncertainties of the sector itself, caution should be taken when relying on LULUCF’s potential to reach the set goals.

Exploring the past through lynchet landscapes in the Vosges Mountains and the Lorraine Plateau (France)

AbstractLynchets are ridges formed by erosion and sediment accumulation downstream of agricultural plots and offer valuable insights into past agricultural activity. These microtopographies cover vast areas and serve as indicators of historical changes in land use. As a result, their ubiquity across Europe makes them particularly interesting. In this study, we propose a geoarchaeological approach to analyze six lynchets, four in the Vosges Mountains and two on the Lorraine Plateau (France). The lynchets can be considered soil archives with no stratigraphic organization or chronological sequence from bottom to top, making it difficult to determine the age of the lynchets and identify changes in land use over time. To this end, we propose the analysis of historical and geo‐historical archives combined with the “pedosedimentary” archives of lynchets through charcoal identification and dating combined with near‐infrared spectroscopy to determine the age, vegetation, and past land use changes associated with lynchet landscapes. By combining these multiple data sources, we are better able to show the chronological development of these ancient agricultural systems and uncover valuable information on landscape history. Charcoal dating suggests a higher frequency of fires from the Middle Ages. The dating aligns with the regional dynamics of anthropogenic fires, indicating a potential use of fire for cultural purposes. We also demonstrate the difficulty of extrapolating the dating of a lynchet to the entire lynchet system. Our results highlight the difficulties of interpreting the formation and dating of lynchets and the lynchet system on the sole basis of charcoal analysis. However, we highlight the value of applying pedoanthracology to lynchets to determine the dynamics of land use change in former fields.

The effects of shrub encroachment on arthropod communities depend on grazing history

Unsustainable grazing is a major driver of biodiversity loss worldwide. Conservation actions such as grazing exclusion are effective strategies for halting such decline. However, we still know little how the long-term impact of grazing exclusion depends on plant–animal interactions such as those between encroaching unpalatable shrubs and ground arthropods. Here, we assessed how encroaching, unpalatable shrub species (Sarcopoterium spinosum) mediates the effects of grazing exclusion on the recovery of arthropod communities. We used a large-scale, long-term (15–25 years) grazing exclusion experiment complemented with local-scale treatments that consider the presence or absence of shrubs. We found that halting overgrazing supported the recovery of biodiversity in the long-term. Notably, the impacts of shrubs on arthropod diversity vary with grazing history. Shrubs decreased arthropod abundance by three folds, affecting particularly flies, butterflies, hymenopteran, and beetles in protected areas. Yet, shrubs had positive effects on animal diversity, particularly centipedes and millipeds in grazed areas. On the one hand, shrubs may enhance biodiversity recovery in overgrazed systems; on the other hand, shrubs may be detrimental in protected areas, in the absence of grazing. Understanding how plant–animal interactions vary with historical land-use change is key for biodiversity conservation and recovery and for integrated management of agroecosystems.

Transformation of treeless depression wetlands in Central Europe over the last 100 years: Włoszczowa Basin (southern Poland) case study

Historical changes in land use and development over the last century were analysed to identify the main causes and directions of changes in depression wetland ecosystems in the Włoszczowa Basin, an area of 1600 km2 in southern Poland. The analysis of Military Cartographic Institute maps and orthophotomaps, as well as field surveys, made it possible to determine the scale of degradation of 247 treeless depression wetlands. It was shown that the nature and extent of transformation of individual wetlands varied depending on the type of wetland and the method of land use in adjacent areas. However, the main anthropogenic factor affecting these changes was land drainage, of which the greatest intensity in Central Europe was pursued during the socialist rule between 1945 and 1989.

Land use land cover and land surface temperature changes and their relationship with human modification in Islamabad Capital Territory, Pakistan.

Human activities are altering the existing patterns of Land Use Land Cover (LULC) and Land Surface Temperature (LST) on a global scale. However, long-term trends of LULC and LST are largely unknown in many remote mountain areas such as the Karakorum. . The objective of our study therefore was to evaluate the historical changes in land use and land cover (LULC) in an alpine environment located in Islamabad Capital Territory, Pakistan. We used Landsat satellite pictures (namely Landsat 5 TM and Landsat 8 OLI) from the years 1988, 2002, and 2016 and applied the Maximum Likelihood Classification (MLC) approach to categorize land use classes. Land Surface Temperatures (LST) were calculated using the thermal bands (6, 10, and 11) of Landsat series data. The correlation between the Human Modification Index (HMI) and LULC as well as LST was evaluated by utilizing data from Google Earth Engine (GEE). Over the study period, the urbanized area increased by 9.94%, whilst the agricultural and bare soil areas decreased by 3.81% and 3.94%, respectively. The findings revealed a significant change in the LULC with a decrease of 1.99% in vegetation. The highest LST class exhibited a progressive trend, with an increase from 12.27% to 48.48%. Based on the LST analysis, the built-up area shows the highest temperature, followed by the barren, agricultural, and vegetation categories. Similarly, the HMI for different LST categories indicates that higher LST categories have higher levels of human alteration compared to lower LST categories, with a strong correlation (R-value = 0.61) between HMI and LST. The findings can be utilized to promote sustainable urban management and for biodiversity conservation efforts. The work also has the potential of utilizing it to protect delicate ecosystems from human interference and to formulate strategies and regulations for sustainable urban growth, including aspects of land utilization and zoning, reduction of urban heat stress, and urban infrastructure.

Distinct spatial patterns of genetic structure and diversity in the butterfly Marbled White (Melanargia galathea) inhabiting fragmented grasslands

We adopted a landscape-scale approach to analyze the genetic patterns (diversity, structure, and differentiation) of the Marbled White (Melanargia galathea). This butterfly species is characteristic of semi-dry grasslands, which have substantially declined in Switzerland during past decades. We sampled individuals on a regular grid of the established Biodiversity Monitoring program of Switzerland over five consecutive years, obtaining 1639 genotyped individuals from 185 locations. Results showed that M. galathea populations cluster into five spatially aggregated clusters that largely coincide with the biogeographic regions of Switzerland. Genetic diversity (allelic richness) was higher in the South of the Alps, likely related to immigration dynamics that suggest recolonisation from the South after the last glaciation. Demographic history resulted in distinct isolation by distance (IBD) and by cumulative elevational difference (isolation by altitude, IBA) at large scale, while regional IBD and IBA were less pronounced. This pattern was likely induced by the barrier effect of the high mountains of the Alps impeding continuous northward migration after the last glacial maximum. A temporal analysis revealed that regional genetic diversity did not change strongly during the five sampling years. This result indicates that the genetic diversity pattern in M. galathea has not been noticeably affected by historical land-use change or that the sampling period of five years is too short to detect any changes. Our findings highlight the regionally, topography-induced distinct genetic clusters, relevant for consideration as conservation units and likely reflecting genetic structures similar to those found in other butterfly species of conservation concern.

Projection of further expansion of oil palm plantation in Jambi Province

The expansion of oil palm plantations has become of global concern. Jambi province in Indonesia is one of the regions experiencing a rapid shift in land use, and oil palm plantation, settlement, and agriculture has emerged as the primary force behind this shift. This study aims to project scenarios of future land-use change and expansion of oil palm plantation in Jambi Province in 2030, 2060, and 2100. Projections of land-use change scenarios are conducted using the Land Change Modeler (LCM) in which Cellular Automata Markov (CA-Markov) is the model base. The validation of model against historic land-use changes showed an overall kappa value of 0.97. In the no-conservation scenario assuming a continuation of the trends from 1990 to 2011, the forest area is continuing to decrease. . Oil palm would replace forest as dominant land-use cover in Jambi Province in 2100. Driving factors explaining the spatial distribution of oil palm plantation expansion include distance from forest, distance from road, and elevation. Our study shows the importance of government regulations to to slow or stop deforestation especially for forests near plantations.

Early Warning of the Carbon-Neutral Pressure Caused by Urban Agglomeration Growth: Evidence from an Urban Network-Based Cellular Automata Model in the Greater Bay Area

Carbon neutrality is becoming an important development goal for regions and countries around the world. Land-use cover/change (LUCC), especially urban growth, as a major source of carbon emissions, has been extensively studied to support carbon-neutral planning. However, studies have typically used methods of small-scale urban growth simulation to model urban agglomeration growth to assist in carbon-neutral planning, ignoring the significant characteristics of the process to achieve carbon neutrality: large-scale and long-term. This paper proposes a framework to model large-scale and long-term urban growth, which couples a quantity module and a spatial module to model the quantity and spatial allocation of urban land, respectively. This framework integrates the inertia of historical land-use change, the driving effects of the urbanization law (S-curve), and the traction of the urban agglomeration network to model the long-term quantity change of urban land. Moreover, it couples a partitioned modeling framework, spatially heterogeneous rules derived by geographically weighted regression (GWR), and quantified land-use planning orientations to build a cellular automata (CA) model to accurately allocate the urbanized cells in a large-scale spatial domain. Taking the Guangdong–Hong Kong–Macao Greater Bay Area (GHMGBA) as an example, the proposed framework is calibrated by the urban growth from 2000 to 2010 and validated by that from 2010 to 2020. The figure of merit (FoM) of the results simulated by the framework is 0.2926, and the simulated results are also assessed by some evidence, which both confirm the good performance of the framework to model large-scale and long-term urban growth. Coupling with the coefficients proposed by the Intergovernmental Panel on Climate Change (IPCC), this framework is used to project the carbon emissions caused by urban growth in the GHMGBA from 2020 to 2050. The results indicate that Guangzhou, Foshan, Huizhou, and Jiangmen are under great pressure to achieve the carbon-neutral targets in the future, while Hong Kong, Macao, Shenzhen, and Zhuhai are relatively easy to bring up to the standard. This research contributes to the ability of land-use models to simulate large-scale and long-term urban growth to predict carbon emissions and to support the carbon-neutral planning of the GHMGBA.

Salinification of Coastal Wetlands and Freshwater Management to Support Resilience

Climates are rapidly changing in wetland ecosystems around the world and historical land-use change is not always given enough consideration in climate adaptation discussions. Historical changes to hydrology and other key environments can exacerbate vegetation stress; e.g., recent drought and flood episodes are likely more extreme because of climate change. The contributions of global and regional changes that affect groundwater and surface water availability all need consideration in conservation planning including sea-level rise, coastal subsidence and compaction, fluid extraction, and floodplain reengineering. Where subsidence is not too extreme, healthy coastal vegetation often can keep ahead of sea-level rise by accreting elevation through sedimentary and/or biogenic processes. Better water conservation and minimum water delivery during drought may support foundational species and avoid wetland collapse. Local approaches have been developed to rewet inland floodplains decades after their reengineering for agricultural and urban development to support biodiversity in salinified coastal wetlands. The purpose of this paper is to describe inland wetland remediation techniques that may also be useful to increase freshwater delivery to coastal wetlands experiencing salinification. While some salinified coastal ecosystems may transition in the future, attempts can be made to remediate salinification related to historical land use in support of wetland conservation, health, and sustainability.

Designing Urban Green Infrastructures Using Open-Source Data—An Example in Çiğli, Izmir (Turkey)

The city of Izmir (Turkey) has experienced one of the most rapid and fastest urbanization processes in the last thirty years; more than 33 thousand hectares of agricultural and seminatural land have been transformed into urban areas, leading to a drastic reduction of biodiversity and hard deployments of the ecosystem service supply. In this perspective, the potential definition of methodologies to design multifunctional green infrastructures is extremely important to challenge the effects of climate change. The aim of this study is to propose an easy and replicable methodology to design a Green Infrastructure at the neighbourhood level in one of the most important districts of Izmir: Çiğli. To this end, we combined historical land-use change analysis (based on Urban Atlas, Copernicus Land Monitoring Service) with environmental and ecosystem mapping in a Geographic Information System environment (ESRI ArcMap 10.8.1) while creating a composite layer based on unweighted overlays of Imperviousness, Tree Cover Density, and Habitat Quality. Results were used to design the Green Infrastructure of Çiğli and suggest context-based strategies for urban adaptation, including Nature-Based Solutions for core, edge, and urban links.

The resilience of soil erosion rates under historical land use change in agroecosystems of Southern Spain

Land use change (LUC) is identified as one of the main drivers of soil erosion in the Mediterranean. However, very little information exists regarding the relationship between land use and erosion over longer time periods and on regional scales. We quantified the LUC in Southern Spain between 1956 and 2018, examining its effect on soil erosion and assessing the mitigation role of the permanent grassland (PG). The land use influence on erosion is represented by the RUSLE's C-factor, which was modelled using the Monte Carlo Method (MCM) based on historical LUC. Moreover, future LUC scenarios by 2038 were developed by binary logistic model (scFS) and by a complete conversion of PG to cropland (scPC), permanent crop (scPP) and forest and natural (scFP). Historically, Southern Spain has experienced an impressive intensification of its agricultural system. While soil loss variation is noted within the classes, no big variation is observed in cumulative erosion on a regional scale. The underlying reasons for this resilience are multifold, but mainly attributed to the fact that a small fraction of the total surface (20%), dominates total erosion (67%). The C-factor decrease in this area displays a LUC towards forest and natural area, suggesting an agriculture abandonment. On the other hand, the agricultural intensification that has taken place in the remainder of the area, contributes much less to overall soil erosion. Future LUC scenarios illustrate the importance of PG for erosion mitigation. scFS scenario does not project major changes. However, scCP and scPP, show an abrupt increase in regional erosion by 13% and 14%, while scFP shows a negligible reduction of erosion close to 0%. This allows to quantify the erosion mitigation offered by maintaining the PG and should be taken into account for future agricultural policy.

Problems seeded in the past: lagged effects of historical land-use changes can cause an extinction debt in long-lived species due to movement limitation

ContextLand-use change is one of the main threats to biodiversity on the global scale. Legacy effects of historical land-use changes may affect population dynamics of long-lived species, but they are difficult to evaluate through observational studies alone. We present here an interdisciplinary modelling approach as an alternative to address this problem in landscape ecology.ObjectivesAssess effects of agricultural abandonment and anthropisation on the population dynamics of long-lived species. Specifically, we evaluated: (a) how changes in movement patterns caused by land-use change might impact population dynamics; (b) time-lag responses of demographic variables in relation to land-use changes.MethodsWe applied an individual-based and spatial-explicit simulation model of the spur-tighed tortoise (Testudo graeca), an endangered species, to sequences of real-world landscape changes representing agricultural abandonment and anthropisation at the local scale. We analysed different demographic variables and compared an “impact scenario” (i.e., historical land-use changes) with a “control scenario” (no land-use changes).ResultsWhile agricultural abandonment did not lead to relevant changes in demographic variables, anthropisation negatively affected the reproductive rate, population density and the extinction probability with time-lag responses of 20, 30 and 130 years, respectively, and caused an extinction debt of 22%.ConclusionsWe provide an understanding of how changes in animal movement driven by land-use changes can translate into lagged impacts on demography and, ultimately, on population viability. Implementation of proactive mitigation management are needed to promote landscape connectivity, especially for long-lived species for which first signatures of an extinction debt may arise only after decades.

Are Land‐Use Change Emissions in Southeast Asia Decreasing or Increasing?

AbstractSoutheast Asia is a region known for active land‐use changes (LUC) over the past 60 years; yet, how trends in net CO2 uptake and release resulting from LUC activities (net LUC flux) have changed through past decades remains uncertain. The level of uncertainty in net LUC flux from process‐based models is so high that it cannot be concluded that newer estimates are necessarily more reliable than older ones. Here, we examined net LUC flux estimates of Southeast Asia for the 1980s−2010s from older and newer sets of Dynamic Global Vegetation Model simulations (TRENDY v2 and v7, respectively), and forcing data used for running those simulations, along with two book‐keeping estimates (H&N and BLUE). These estimates yielded two contrasting historical LUC transitions, such that TRENDY v2 and H&N showed a transition from increased emissions from the 1980s to 1990s to declining emissions in the 2000s, while TRENDY v7 and BLUE showed the opposite transition. We found that these contrasting transitions originated in the update of LUC forcing data, which reduced the loss of forest area during the 1990s. Further evaluation of remote sensing studies, atmospheric inversions, and the history of forestry and environmental policies in Southeast Asia supported the occurrence of peak emissions in the 1990s and declining thereafter. However, whether LUC emissions continue to decline in Southeast Asia remains uncertain as key processes in recent years, such as conversion of peat forest to oil‐palm plantation, are yet to be represented in the forcing data, suggesting a need for further revision.