Land Use Change Scenarios Research Articles

Exploring and Predicting the Individual, Combined, and Synergistic Impact of Land-Use Change and Climate Change on Streamflow, Sediment, and Total Phosphorus Loads

The present study predicts and assesses the individual, combined, and synergistic effect of land-use change and climate change on streamflow, sediment, and total phosphorus (TP) loads under the present and future scenarios by using the Soil and Water Assessment Tool (SWAT). To predict the impacts of climate and land-use change on streamflow, sediment, and TP loads, there are 46 scenarios composed of historical climate, baseline period climate, eight climate models of Coupled Model Intercomparison Project phase 5 (CMIP5) of two representative emission pathways (RCP4.5 and RCP8.5), after downscaled and bias-corrected, two observed land-use maps (LULC 1995, LULC 2015) and the projected two future land-use maps (LU2055 and LU 2075) with the help of CA-Markov model to be fed into SWAT. The central tendency of streamflow, sediment, and TP loads under future scenarios is represented using the annual average. The intra-/inter-annual variation of streamflow, sediment, and TP loads simulated by SWAT is also analyzed using the coefficient of variation. The results show that future land-use change has a negligible impact on annual streamflow, sediment, TP loads, and intra-annual and inter-annual variation. Climate change is likely to amplify the annual streamflow and sediment and reduce the annual TP loads, which is also expected to reduce its inter-/intra-annual variation of TP loads compared with the baseline period (2000–2019). The combined impact of land-use and climate change on streamflow, sediment, and TP loads is greater than the sum of individual impacts for climate change and land-use change, especially for TP loads. Moreover, the synergistic impact caused by the interaction of climate and land use varies with variables and is more significant for TP loads. Thus, it is necessary to consider the combined climate and land-use change scenarios in future climate change studies due to the non-negligible synergistic impact, especially for TP loads. This research rare integrates the individual/combined/synergistic impact of land-use and climate change on streamflow, sediment, and TP loads and will help to understand the interaction between climate and land-use and take effective climate change mitigation policy and land-use management policy to mitigate the non-point source pollution in the future.

Ecosystem carbon balance in the Hawaiian Islands under different scenarios of future climate and land use change

The State of Hawai‘i passed legislation to be carbon neutral by 2045, a goal that will partly depend on carbon sequestration by terrestrial ecosystems. However, there is considerable uncertainty surrounding the future direction and magnitude of the land carbon sink in the Hawaiian Islands. We used the Land Use and Carbon Scenario Simulator (LUCAS), a spatially explicit stochastic simulation model that integrates landscape change and carbon gain-loss, to assess how projected future changes in climate and land use will influence ecosystem carbon balance in the Hawaiian Islands under all combinations of two radiative forcing scenarios (RCPs 4.5 and 8.5) and two land use scenarios (low and high) over a 90 year timespan from 2010 to 2100. Collectively, terrestrial ecosystems of the Hawaiian Islands acted as a net carbon sink under low radiative forcing (RCP 4.5) for the entire 90 year simulation period, with low land use change further enhancing carbon sink strength. In contrast, Hawaiian terrestrial ecosystems transitioned from a net sink to a net source of CO2 to the atmosphere under high radiative forcing (RCP 8.5), with high land use accelerating this transition and exacerbating net carbon loss. A sensitivity test of the CO2 fertilization effect on plant productivity revealed it to be a major source of uncertainty in projections of ecosystem carbon balance, highlighting the need for greater mechanistic understanding of plant productivity responses to rising atmospheric CO2. Long-term model projections such as ours that incorporate the interactive effects of land use and climate change on regional ecosystem carbon balance will be critical to evaluating the potential of ecosystem-based climate mitigation strategies.

It's a keeper: Valuing the carbon storage service of Agroforestry ecosystems in the context of CAP Eco-Schemes

Agroforestry landscapes provide multiple benefits, including the capacity for storing carbon, thus contributing to climate change mitigation. In Portugal, the agroforestry system known as Montado (Dehesa in Spain) is heavily dependent on national and European financial incentives. Lack thereof, or insufficient level, often results in abandonment or intensification (increasing grazing pressure) of management practices. Carbon storage is a stock externality of agroforestry systems currently not targeted by CAP agri-environmental mechanisms. Hence, our work is aimed at assessing and valuing net carbon flow in agroforestry systems to guide a Payment for Ecosystem Services (PES) scheme targeting Montado landscapes in Portugal. We have assessed and valued net carbon flow for different land-use change scenarios (abandonment, maintenance, or grazing intensification), focusing on cork and holm oak-dominated Montado and using biomass equations. We applied different explicit carbon pricing mechanisms (market value, social cost, and shadow price) to determine a range of values suitable as financial rewards in the proposed PES scheme. For cork-oak Montado, our results suggest both abandonment and grazing intensification are linked to carbon emissions (−1.5 and −1.6tCO2eq.ha-1.year-1, respectively), whereas maintaining Montado results in carbon sequestration (+0.9tCO2eq.ha-1.year-1). Similar results were found for holm oak. Based on this biophysical assessment, we estimate that farmers willing to maintain Montado systems are eligible to be rewarded between 106 and 149€.ha-1.year-1 through a PES scheme for the increase in carbon storage they are providing. Incorporating the value of ecosystem services into direct financial rewards could ensure agroforestry systems are kept under sustainable management and continue to supply multiple benefits to society.

Response of Runoff to Extreme Land Use Change in the Permafrost Region of Northeastern China

To study the response of runoff to extreme changes in land use, the Soil and Water Assessment Tool (SWAT) model was used to construct historical, extreme, and future scenarios for several major landscape types in a permafrost region of northeastern China. The results show that the SWAT model is applicable in the Tahe River Basin; forestlands, shrublands, wetlands, and grasslands are the main land-use types in this basin, and the transfers among them from 1980–2015 have impacted runoff by less than 5%. Under extreme land use-change scenarios, the simulated runoff decreased from grasslands, to wetlands, shrublands, and finally, forestlands. The conversion of extreme land-use scenarios produces different hydrological effects. When forestland is converted to grassland, runoff increases by 25.32%, when forestland is converted to wetland, runoff increases by 13.34%, and the conversion of shrubland to forestland reduces runoff by 13.25%. In addition, the sensitivity of runoff to different land-use changes was much greater during flood seasons than in dry seasons. Compared to the reference year of 2015, the annual simulated runoff under the two future land-use scenarios (shrublands to forestlands and shrublands to wetland) was less. Also, both future land-use scenarios showed effects to decrease flooding and increased dryness, This study provided important insight into the integrated management of land use and water resources in the Tahe River Basin and the permafrost region of northeastern China.

Multi-Scenario Prediction of Intra-Urban Land Use Change Using a Cellular Automata-Random Forest Model

The simulation of future land use can provide decision support for urban planners and decision makers, which is important for sustainable urban development. Using a cellular automata-random forest model, we considered two scenarios to predict intra-land use changes in Kumamoto City from 2018 to 2030: an unconstrained development scenario, and a planning-constrained development scenario that considers disaster-related factors. The random forest was used to calculate the transition probabilities and the importance of driving factors, and cellular automata were used for future land use prediction. The results show that disaster-related factors greatly influence land vacancy, while urban planning factors are more important for medium high-rise residential, commercial, and public facilities. Under the unconstrained development scenario, urban land use tends towards spatially disordered growth in the total amount of steady growth, with the largest increase in low-rise residential areas. Under the planning-constrained development scenario that considers disaster-related factors, the urban land area will continue to grow, albeit slowly and with a compact growth trend. This study provides planners with information on the relevant trends in different scenarios of land use change in Kumamoto City. Furthermore, it provides a reference for Kumamoto City’s future post-disaster recovery and reconstruction planning.

Stochastic community assembly decreases soil fungal richness in arid ecosystems.

Uncovering the linkages between community assembly and species diversity is a fundamental issue in microbial ecology. In this study, a large-scale (transect intervals of 1257.6km) cross-biome soil survey was conducted, which ranged over agricultural fields, forests, wetlands, grasslands and desert, in the arid regions of northwest China. The aim was to investigate the biogeographic distribution, community assembly and species co-occurrence of soil fungi. The fungal communities in agricultural soils exhibited a steeper distance-decay slope and wider niche breadths, and were more strongly affected by stochastic assembly processes, than fungi in other natural habitats. A strong relationship was revealed between soil fungal richness and community assembly in arid ecosystems, with the influence of stochastic assembly processes decreasing with increasing fungal richness. Moreover, aridity was the most important environmental factor influencing fungal richness, β-diversity and species co-occurrence patterns. Specifically, the predicted increase in arid conditions will probably reduce fungal richness and network complexity. These findings represent a considerable advance in linking fungal richness to mechanisms underlying the biogeographic patterns and assembly processes of fungal communities in arid ecosystems. These results can thus be used to forecast species co-occurrence and diversities pattern of soil fungi under climate aridity and land-use change scenarios.

Dynamics of soil organic carbon in the steppes of Russia and Kazakhstan under past and future climate and land use

Changes in land use and climate are the main drivers of change in soil organic matter contents. We investigated the impact of the largest policy-induced land conversion to arable land, the Virgin Lands Campaign (VLC), from 1954 to 1963, of the massive cropland abandonment after 1990 and of climate change on soil organic carbon (SOC) stocks in steppes of Russia and Kazakhstan. We simulated carbon budgets from the pre-VLC period (1900) until 2100 using a dynamic vegetation model to assess the impacts of observed land-use change as well as future climate and land-use change scenarios. The simulations suggest for the entire VLC region (266 million hectares) that the historic cropland expansion resulted in emissions of 1.6⋅ 1015 g (= 1.6 Pg) carbon between 1950 and 1965 compared to 0.6 Pg in a scenario without the expansion. From 1990 to 2100, climate change alone is projected to cause emissions of about 1.8 (± 1.1) Pg carbon. Hypothetical recultivation of the cropland that has been abandoned after the fall of the Soviet Union until 2050 may cause emissions of 3.5 (± 0.9) Pg carbon until 2100, whereas the abandonment of all cropland until 2050 would lead to sequestration of 1.8 (± 1.2) Pg carbon. For the climate scenarios based on SRES (Special Report on Emission Scenarios) emission pathways, SOC declined only moderately for constant land use but substantially with further cropland expansion. The variation of SOC in response to the climate scenarios was smaller than that in response to the land-use scenarios. This suggests that the effects of land-use change on SOC dynamics may become as relevant as those of future climate change in the Eurasian steppes.

Climate and land-use change impacts on spatiotemporal variations in groundwater recharge: A case study of the Bangkok Area, Thailand

Groundwater contributes to the socioeconomic development of the Thai capital Bangkok and its vicinity. However, groundwater resources are under immense pressure due to population growth, rapid urbanisation, overexploitation, and climate change. Therefore, evaluating the combined impact of climate change and land-use change on groundwater recharge can be useful for developing sound groundwater management systems. In this research, the future climate is projected using three Regional Climate Models (RCMs), namely ACCESS-CSIRO-CCAM, CNRM-CM5-CSIRO-CCAM, and MPI-ESM-LR-CSIRO-CCAM for three future periods: near future (2010–2039), mid future (2040–2069), and far future (2070–2099) under two Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5 as suggested in the IPCC's Fifth Assessment Report. All RCMs project the temperature to rise incessantly, although future precipitation is predicted to fluctuate (increase and decrease) among the various RCMs and RCP scenarios. A Dyna-CLUE model is employed to analyse the future land-use change scenarios (low, medium, and high urbanisation), with the aim of expanding the built-up area and creating land-use maps covering the period to 2099. A hydrological model, WetSpass, is used to estimate groundwater recharge under future climate and land-use change. The findings reveal that groundwater recharge is expected to decrease in high and medium urbanisation areas, ranging from 5.84 to 20.91 mm/yr for the RCP 4.5 scenario and 4.07 to 18.72 mm/yr for RCP 8.5. In contrast, for the low urbanisation scenario, the model projects an increase in groundwater recharge ranging from 7.9 to 16.66 mm/yr for the RCP 4.5 scenario and 5.54 to 20.04 mm/yr for RCP 8.5.

Drivers, Impacts and Mitigation of Increased Sedimentation in the Hydropower Reservoirs of East Africa

Hydropower reservoirs are essential for the climate-neutral development of East Africa. Hydropower production, however, is threatened by human activities that lead to a decrease in water storage capacity of reservoirs. Land use/land cover and climatic changes are driving accelerated soil erosion in semi-arid East Africa, which ultimately increases reservoir sedimentation and decreases energy production. Sediment delivery dynamics at the catchment scale are complex, involving the interaction of multiple factors and processes on different spatial and temporal scales. A lack of understanding of these processes and their interactions may impede the efficiency of sediment mitigation and control strategies. A deep understanding of the processes of erosion and connectivity of the land to river channel, as well as storage of eroded material within hillslopes and floodplains, and sediment accumulation in the reservoirs supports selection of future dam locations and sustainable management of reservoirs. The sediment budget approach can provide such a holistic perspective by accounting for the various sediment sources, transport, sinks, and redistribution when the sediment is routed through that catchment. Constructing sediment budgets is challenging, but the potential for integrating a number of different techniques offers new opportunities to collect the required information. In East Africa, the spatial planning of dams is mainly dominated by political and financial motives, and impacts of land use and climate on the sediment transport dynamics are not adequately considered. Production of sediment budgets under different scenarios of land use and climate change should be an essential step when deciding the location and management strategies for dams. Selection of new hydroelectric reservoir sites must consider long-term scientific data on climate change, and the sediment budget components for sustainable land management planning, hydropower sustainability.

Landuse changes simulation for erosion control in the Asahan Hulu Sub Watershed

Landuse changes that don’t follow the principles of land conservation are susceptible to erosion, sedimentation, and flooding. This study aims to determine the most optimal land use scenario in order to reduce the rate of erosion and analyse the effect of land use change on erosion. This research was conducted by collecting rainfall data, soil type maps, slope maps, and land use maps then overlaid using arc GIS and then calculating the erosion value. The simulation is done by reducing production land cover index and increasing forest landcover index. The results showed that the annual erosion value in existing condition was 111.67 tonnes / ha / year which is moderate erosion hazard class. The amount of increasing forest land cover area in scenario I is about 2881.80 ha, scenario II is about 5266.95 ha, and scenario III is about 7652.12 ha. The reduced erosion in each scenario of landuse change is 103.489 tonnes/ ha / year, in scenario 1, 93.642 tonnes / ha / year at scenario II, and 87.358 tonnes / ha / yr at scenario III.

The simulation of landuse change scenarios on Bedagai Sub Watershed health condition

Erosion is one of three indicators that showed the health condition of watershed. The most important human intervention factor that influence condition of erosion is landuse. This study aimed to calculate the erosion value at existing condition on Bedagai Sub Watershed and optimizing watershed management by simulating some scenarios based on addition of forest land cover index to analyse its effects on erosion value. The calculation of erosion using USLE Method and ArcGIS 10.3 application. There are three scenarios simulated using Arc GIS 10.3 which is in each scenario the addition of forest land cover is about 5%. The forest land cover in existing condition is about 4%, in the scenario 1 is about 10% landcover index, scenario 2 is about 15% forest landcover index, and scenario 3 is about 20% forest landcover index. The result shown in existing condition, the erosion value was 209.74 ton/ha/year which classified as high hazard level. The simulation of three scenarios shown the erosion value by applying scenario 1 was 169.97 ton/ha/year, scenario 2 was126.52, and scenario 3 was 95.97 which is in medium hazard level.

Diverging land-use projections cause large variability in their impacts on ecosystems and related indicators for ecosystem services

Abstract. Land-use models and integrated assessment models provide scenarios of land-use and land-cover (LULC) changes following pathways or storylines related to different socioeconomic and environmental developments. The large diversity of available scenario projections leads to a recognizable variability in impacts on land ecosystems and the levels of services provided. We evaluated 16 projections of future LULC until 2040 that reflected different assumptions regarding socioeconomic demands and modeling protocols. By using these LULC projections in a state-of-the-art dynamic global vegetation model, we simulated their effect on selected ecosystem service indicators related to ecosystem productivity and carbon sequestration potential, agricultural production and the water cycle. We found that although a common trend for agricultural expansion exists across the scenarios, where and how particular LULC changes are realized differs widely across models and scenarios. They are linked to model-specific considerations of some demands over others and their respective translation into LULC changes and also reflect the simplified or missing representation of processes related to land dynamics or other influencing factors (e.g., trade, climate change). As a result, some scenarios show questionable and possibly unrealistic features in their LULC allocations, including highly regionalized LULC changes with rates of conversion that are contrary to or exceed rates observed in the past. Across the diverging LULC projections, we identified positive global trends of net primary productivity (+10.2 % ± 1.4 %), vegetation carbon (+9.2 % ± 4.1 %), crop production (+31.2 % ± 12.2 %) and water runoff (+9.3 % ± 1.7 %), and a negative trend of soil and litter carbon stocks (−0.5 % ± 0.4 %). The variability in ecosystem service indicators across scenarios was especially high for vegetation carbon stocks and crop production. Regionally, variability was highest in tropical forest regions, especially at current forest boundaries, because of intense and strongly diverging LULC change projections in combination with high vegetation productivity dampening or amplifying the effects of climatic change. Our results emphasize that information on future changes in ecosystem functioning and the related ecosystem service indicators should be seen in light of the variability originating from diverging projections of LULC. This is necessary to allow for adequate policy support towards sustainable transformations.

Interrelated impacts of climate and land-use change on a widespread waterbird.

Together climate and land-use change play a crucial role in determining species distribution and abundance, but measuring the simultaneous impacts of these processes on current and future population trajectories is challenging due to time lags, interactive effects and data limitations. Most approaches that relate multiple global change drivers to population changes have been based on occurrence or count data alone. We leveraged three long-term (1995-2019) datasets to develop a coupled integrated population model-Bayesian population viability analysis (IPM-BPVA) to project future survival and reproductive success for common loons Gavia immer in northern Wisconsin, USA, by explicitly linking vital rates to changes in climate and land use. The winter North Atlantic Oscillation (NAO), a broad-scale climate index, immediately preceding the breeding season and annual changes in developed land cover within breeding areas both had strongly negative influences on adult survival. Local summer rainfall was negatively related to fecundity, though this relationship was mediated by a lagged interaction with the winter NAO, suggesting a compensatory population-level response to climate variability. We compared population viability under 12 future scenarios of annual land-use change, precipitation and NAO conditions. Under all scenarios, the loon population was expected to decline, yet the steepest declines were projected under positive NAO trends, as anticipated with ongoing climate change. Thus, loons breeding in the northern United States are likely to remain affected by climatic processes occurring thousands of miles away in the North Atlantic during the non-breeding period of the annual cycle. Our results reveal that climate and land-use changes are differentially contributing to loon population declines along the southern edge of their breeding range and will continue to do so despite natural compensatory responses. We also demonstrate that concurrent analysis of multiple data types facilitates deeper understanding of the ecological implications of anthropogenic-induced change occurring at multiple spatial scales. Our modelling approach can be used to project demographic responses of populations to varying environmental conditions while accounting for multiple sources of uncertainty, an increasingly pressing need in the face of unprecedented global change.

The neglected contribution of mound-building termites on CH4 emissions in Brazilian pastures

Based on previous reports, our study aimed to obtain the first estimate on the contribution of termite mounds to CH4 emissions in Brazilian Cerrado pastures. We estimated that termite mounds occupy an area larger than 200,000 ha in degraded pastures, an important loss of grazing area considering the current scenario of land-use change of pastures to other crops in Brazil. Moreover, mound-building termites in degraded pastures may be responsible for CH4 emissions greater than 11 Mt CO2 eq. yr−1, [...]

Combining narrative scenarios, local knowledge and land-use change modelling for integrating soil erosion in a global perspective

Mediterranean soil resources are heavily affected by water erosion. There is a need for anticipating the potential impact of land-use change at the catchment scale, considering a range of contrasted possible changes, in order to prepare a relevant adaptation strategy. While participatory scenario approaches are useful for unveiling the diversity of possible futures, their outputs generally take the form of narratives that may be difficult to relate to biophysical models used for simulating soil and water processes. We addressed this challenge by developing a methodology combining narrative scenarios and land-use change modelling at the catchment scale, interacting with local stakeholders who were involved throughout the research, in line with current Land System research. First, we built contrasted scenarios, each with a narrative story and quantitative assumptions for key variables. Then we drew up rules for translating narrative scenarios into spatially explicit maps based on expert groups and local knowledge, simulating the evolution of land use over time. Third, we evaluated and validated the final scenarios by conducting two workshops with scientists and local stakeholders. Finally, we assessed the impact of these scenarios on agricultural production and erosion control. This approach was implemented in the Tleta basin (Morocco), a 180 km2 rural watershed, 10 km from Tangiers and heavily affected by water erosion. As a result, we propose three contrasted spatially explicit land-use change scenarios by 2040. Our work highlights the interest of combining narrative storylines and land-use modelling when developing spatially explicit scenarios at the catchment scale, incorporating the local knowledge of stakeholders. The combination of Land System and ecosystem frameworks contributes to integrating the soil erosion issue in a more global perspective, and lays the foundation for building sustainable strategies for Mediterranean catchments affected by soil erosion.

Response of hydrological processes to climate and land use changes in Hiso River watershed, Fukushima, Japan

Hiso River watershed (HRW) is within a radiocesium contaminated area caused by the disaster in Fukushima Daiichi nuclear power plant (FDNPP). The FDNPP accident resulted in enormous changes in land use in HRW. It's urgently needed to evaluate impacts of climate and land-use changes on hydrological process, which further control pollutants transport in HRW. A combination method of Statistical DownScaling Model (SDSM) and Soil and Water Assessment Tool (SWAT) was applied to generate future climatic and hydrologic variables. Future climate data was obtained from three Representative Concentration Pathway (RCP2.6, 4.5 and 8.5) scenarios of a single General Circulation Models in three future periods of 2030s, 2060s and 2090s (2010–2039, 2040–2069, 2070–2099), with a baseline period (1980–2009). According to land-use change in HRW during 2013–2017, three land-use change scenarios under the three future climate scenarios were established. Results suggested that SDSM showed good capabilities in capturing daily maximum/minimum temperature and precipitation. The SWAT model presented good performances in simulating monthly and yearly streamflow. Results also suggested projected higher temperatures and lower rainfall led to decreased annual water yield and evapotranspiration (ET). The annual water yield and ET decreased in most seasons while had a slight increase in spring. RCP8.5 scenario always generated larger magnitudes for climatic variables and water balance components compared with other climate scenarios. Land-use changes had strong impact on surface runoff and groundwater flow. These results emphasize the necessity of considering impacts of climate and land-use changes on hydrological processes when making decontamination policy in radiocesium contaminated areas.

Remotely-sensed evapotranspiration for informed urban forest management

With higher evapotranspiration (ET) rates compared to other urban land covers, urban forests can play an important role in stormwater flood reduction. Effective incorporation of urban forests into stormwater planning and green infrastructure design requires methods that can quantify ET across mixed-land use landscapes but with sufficient spatial resolution for parcel-specific rates. We used Landsat-derived ET from 2000 to 2018 to estimate 30-m annual ET rates across the City of Virginia Beach, USA, a large urban landscape with increasing flood concerns. Our objectives were to compare ET rates across land covers and then identify land attributes and models to explain spatial ET variation. Upland and wetland forests had higher ET compared to urban areas, where wetland forest had annual ET rates 3–4 times that of urban and contributed ca. 40% of total landscape ET despite covering only 20% of the area. These quantified ET rates highlight the disproportional role that urban forests may play in stormwater runoff reduction, and can inform scenarios of land use change to prioritize forest conservation efforts. Relationships between ET rates and aggregated, higher resolution land attribute data indicated key drivers, where ET increased with canopy cover and decreased with impervious cover and water table depth. A regression model combining these drivers explained approximately 70% of ET variation, providing means to downscale ET estimates to further guide stormwater planning at finer spatial scales. Our findings emphasize the importance of urban forests as green infrastructure elements and point to potential approaches to better incorporate them in stormwater planning decisions.

What Will Remain? Predicting the Representation in Protected Areas of Suitable Habitat for Endangered Tropical Avifauna in Borneo under a Combined Climate- and Land-Use Change Scenario

The responses of threatened tropical avian species to projected climate change and land-use change are important for evaluating the ability of the existing protected areas to provide habitat to these species under future scenarios in biodiversity hotspots. This study uses Maxent, a species distribution model that employs a maximum entropy machine learning approach to map the spatial distributions of habitats suitable for the International Union for Conservation of Nature threatened birds under present and future climate and land-use change in Borneo. We find that the existing protected areas provide very low coverage of the threatened bird species’ suitable habitat areas (95%CI = 9.3–15.4%). Analysis of habitat suitability projections for 18 species of threatened birds suggests that in 2050, under Special Report on Emissions Scenarios A1B and B1, avian species with currently little suitable habitat may gain area but lose in the proportion of this that is protected. Large-ranged species are likely to lose habitat area and this will inflate the proportion of this remaining in protected areas. The present availability of suitable habitat was the most important determinant of future habitat availability under both the scenarios. Threat level, as measured by the International Union for Conservation of Nature and the habitat preferences considered here, Lowland or Lowland–Montane, are poor predictors of the amount of habitat contraction or expansion undergone by the species.

Climate and land use changes shift the distribution and dispersal of two umbrella species in the Hindu Kush Himalayan region

Biodiversity loss from climate and land use change is a global occurrence, but is of particular concern in more prominent biodiverse and sensitive areas such as the Hindu Kush Himalayan (HKH) region. This region harbors two species of geographically separated brown bear (Ursus arctos) - the Tibetan (U. a. pruinosus) and Himalayan brown bear (U. a. isabellinus). Both serve as important umbrella species, providing many ecological benefits to their surrounding ecosystems. However, how these two species from the same taxonomic group but with distinct geographical ranges, will respond to climate and land use change is poorly understood. The aim of this study was to predict the potential impacts of future climate and land use change on the distribution and dispersal paths of Tibetan and Himalayan brown bears in the HKH region. We applied MaxEnt modeling to predict the distribution of the two bear species both currently and for the year 2070, using three General Circulation Models and three scenarios of climate and land use change. We then identified potential dispersal paths using Circuit Theory. Results showed that both species would be negatively affected by the climate and land use change expected in the 2070s. In all three climate scenarios, their distribution areas would both shrink and shift to higher altitudes. Throughout the HKH region, Tibetan and Himalayan brown bears were predicted to lose over 34% and 32% of currently inhabited area under the most severe climate scenario, respectively. In addition, results showed that the density of dispersal paths for Tibetan brown bear would decrease while dispersal resistance would increase, and that dispersal paths for Himalayan brown bears would shift to higher latitudes. To protect these species, the currently suitable distribution areas and dispersal paths should be considered as priority protected areas. Our findings provide a scientific basis for allocating protected areas in the HKH region that are effective under the context of global climate change, and for establishing transboundary cooperation in the HKH region.

Predictive models of distribution and abundance of a threatened mountain species show that impacts of climate change overrule those of land use change

AbstractAimClimate is often the sole focus of global change research in mountain ecosystems although concomitant changes in land use might represent an equally important threat. As mountain species typically depend on fine‐scale environmental characteristics, integrating land use change in predictive models is crucial to properly assess their vulnerability. Here, we present a modelling framework that aims at providing more comprehensive projections of both species’ distribution and abundance under realistic scenarios of land use and climate change, and at disentangling their relative effects.LocationSwitzerland.MethodsWe used the ring ouzel (Turdus torquatus), a red‐listed and declining mountain bird species, as a study model. Based on standardized monitoring data collected across the whole country, we fitted high‐resolution ensemble species distribution models to predict current occurrence probability, while spatially explicit density estimates were obtained from N‐mixture models. We then tested for the effects of realistic scenarios of land use (land abandonment versus farming intensification) and climate change on future species distribution and abundance.ResultsOccurrence probability was mostly explained by climatic conditions, so that climate change was predicted to have larger impacts on distribution and abundance than any scenarios of land use change. In the mid‐term (2030–2050), predicted effects of environmental change show a high spatial heterogeneity due to regional differences in climate and dominant land use, with farming intensification identified as an important threat locally. In the long term (2080–2100), climate models forecast a marked upward range shift (up to +560 m) and further population decline (up to −35%).Main conclusionsOur innovative approach highlights the spatio‐temporal heterogeneity in the relative effects of different environmental drivers on species distribution and abundance. The proposed framework thus provides a useful tool not only for better assessing species’ vulnerability in the face of global change, but also for identifying key areas for conservation interventions at a meaningful scale.