Baird's tapir (Tapirus bairdii) is one of the most emblematic mammals of Mesoamerica, but like other large-bodied animals, it is facing an increasing risk of extinction due primarily to habitat loss. Mexico's 'ortion of the Mesoamerican Biological Corridor (MBC-M) is located in one of the main strongholds for Bairds tapir. To assess the MBC-M's effectiveness for tapir conservation, we estimated the distribution of the species' potential habitat by applying 2 modelling approaches (random forest and Maxent) to a set of uncorrelated environmental variables and a 157-point presence dataset. We calculated the extent of tapir habitat in within the MBC-M and modelled new corridors and conservation areas, which we compared to the MBC-M. Moreover, we assessed deforestation patterns in the region. Twenty-seven percent of highly suitable tapir habitat occurred in protected areas, 15% in corridors and 58.3% was outside the MBC-M and associated reserves. The spatial configuration of the MBC-M was partially concordant with the modelled set of conservation areas and corridors. The main dissimilarity was that the modelled corridors traversed forests in Belize and Guatemala to connect conservation areas. Analyses of deforestation since 1993 and human population density in the vicinity of the MBC-M indicated that future conservation efforts should give particular attention to the Montes Azules-El Triunfo Corridor due to greater habitat threat. The MBC-M has a great potential to play a prominent role in the conservation of tapir habitat but there is an urgent need to implement management plans that reinforce and complement this conservation initiative.

<p><strong>Background</strong>. Human impact over natural ecosystems located in Southern Mexico is increasingly evident. We generated a spatially explicit land use and cover change (LUCC) model to assess current and potential impact of human activities and to identify the influence of variables such as:  distance to paved and unpaved roads, human settlements, rivers, slope and protected areas.</p><p><strong>Study site.</strong> Mesoamerican Biological Corridor located in the state of Chiapas (MBC-Ch), Mexico.</p><p><strong>Methods.</strong> We calibrated a model for the period 1993-2002 and ran a simulation for 2007 which we compared against the real 2007 land use and cover map to evaluate model’s performance. We then projected LUCC to 2030 under three different scenarios: 1) Agriculture and Livestock (AGL), 2) Business As Usual (BAU) and, 3) Conservation (CON).</p><p><strong>Results.</strong> Proximity to roads and settlements increased deforestation probabilities whereas the presence of natural protected areas had the opposite effect. The AGL scenario predicted a reduction of 43 % and 41 % in the extent of closed tropical and temperate forests, respectively. In comparison, the BAU scenario predicted a reduction of 19.5 % in the area covered by closed tropical forest and of 30.1 % in temperate forests. The extent of land destined to farming and forestry increased by 22 % and 15 % in the AGL and BAU scenarios, respectively. In contrast, the CON scenario predicted slight changes in the landscape.</p><p><strong>Conclusions. </strong>Our simulations indicate that it is highly probable to see a marked decay in the extent (and likely integrity) of natural habitats in the MBC-Ch region if a comprehensive series of management actions are not urgently implemented.</p>

Abstract. Land use and land cover change (LULCC) impacts local and regional climates through various biogeophysical processes. Accurate representation of land surface parameters in land surface models (LSMs) is essential to accurately predict these LULCC-induced climate signals. In this work, we test the applicability of the default Noah, Noah-MP, and Community Land Model (CLM) LSMs in the Weather Research and Forecasting (WRF) model over Sub-Saharan Africa. We find that the default WRF LSMs do not accurately represent surface albedo, leaf area index, and surface roughness in this region due to various flawed assumptions, including the treatment of the MODIS woody savanna land use and land cover (LULC) category as closed shrubland. Consequently, we developed a WRF CLM version with more accurate African land surface parameters (CLM-AF), designed such that it can be used to evaluate the influence of LULCC. We evaluate meteorological performance for the default LSMs and CLM-AF against observational datasets, gridded products, and satellite estimates. Further, we conduct LULCC experiments with each LSM to determine if differences in land surface parameters impact the LULCC-induced climate responses. Despite clear deficiencies in surface parameters, all LSMs reasonably capture the spatial pattern and magnitude of near-surface temperature and precipitation. However, in the LULCC experiments, inaccuracies in the default LSMs result in illogical localized temperature and precipitation changes. Differences in thermal changes between Noah-MP and CLM-AF indicate that the temperature impacts from LULCC are dependent on the sensitivity of evapotranspiration to LULCC in Sub-Saharan Africa. Errors in land surface parameters indicate that the default WRF LSMs considered are not suitable for LULCC experiments in tropical or Southern Hemisphere regions and that proficient meteorological model performance can mask these issues. We find CLM-AF to be suitable for use in Sub-Saharan Africa LULCC studies, but more work is needed by the WRF community to improve its applicability to other tropical and Southern Hemisphere climates.

Climate change, habitat loss and fragmentation, invasive species, and resource over-exploitation are among the major factors driving biodiversity loss and the current global change crisis. Maintaining and restoring connectivity throughout fragmented landscapes is key to reduce habitat isolation and mitigate anthropogenic impacts. To date, few connectivity approaches seek to identify corridors along climate gradients and least transformed natural habitats despite its importance to facilitate dispersal of organisms, as species' ranges shift over time to track suitable climates. In this study, we identified least-cost climatic corridors in Mexico between 2027 old-growth vegetation patches incorporating evapotranspiration as climatic variable, Euclidean distances, and human impact. We identified old-growth vegetation patches using the land use and vegetation map of 2011 (scale 1:250 000) by the National Institute of Statistics and Geography (INEGI). Moreover, we calculated a human impact index based on the theoretical framework of the Global Biodiversity Model (Alkemade et al. 2009) but adapted for Mexico (Mexbio, Kolb 2016), and includes the impact of land use, road infrastructure and fragmentation based on the land use and vegetation map of 2011 and a road map by the Mexican Institute of Transportation. We modeled corridors for a baseline period (1980-2009) and under three future time periods (2015-2039, 2045-2069 and 2075-2099), corresponding to four Global Circulation Models (MPI-ESM-LR, GFDL-CM3, HADGEM2-ES and CNRMCM5) each under two emission scenarios (RCP 4.5 and 8.5) The historical and future evapotranspiration values were calculated using the climate surfaces from Cuervo-Robayo et al. 2019 and from the Center of Atmospheric Sciences of the National Autonomous University of Mexico*1, respectively. The historical and future evapotranspiration values were calculated using the climate surfaces from Cuervo-Robayo et al. 2019 and from the Center of Atmospheric Sciences of the National Autonomous University of Mexico, respectively. We used the Turc evapotranspiration equation (Turc 1954) to estimate actual evapotranspiration. Least cost climatic corridors using future climate projections were used to test the assumption that climatic gradients are maintained in the future. We then prioritized climatic corridors using a multicriteria analysis guided by expert knowledge, incorporating factors such as indicators of human impact, vulnerability and exposure to climate change, and priority sites for biodiversity conservation and restoration. On average, more than 4,500 least cost climatic corridors were identified for each scenario. There is a high spatial coincidence in the geographical location of current and future climatic corridors (overlap &gt; 90%). Fewer corridors were identified in the northern part of the country where natural vegetation is less fragmented, whereas in central and southern Mexico landscape fragmentation is greater, resulting in an increased number of corridors (Fig. 1). The use of open spatial data was key in identifying climatic corridors in order to support decision-making. The results provide a spatial guide to implement conservation and restoration actions to promote connectivity, in particular among climatic stable areas, thus supporting the achievement of Aichi Targets and Sustainable Development Goals. Also, it informs multiple stakeholders and sectors in land-use planning decisions and to promote the alignment of existing incentives to reduce habitat loss, degradation and fragmentation in key areas needed to maintain and recover landscape connectivity in the face of global change.

Mexican oak forests (genus Quercus) are frequently used for traditional charcoal production. Appropriate management programs are needed to ensure their long-term use, while conserving the biodiversity and ecosystem services, and associated benefits. A key variable needed to design these programs is the spatial distribution of standing woody biomass. A state-of-the-art methodology using small format aerial photographs was developed to estimate the total aboveground biomass (AGB) and aboveground woody biomass suitable for charcoal making (WSC) in intensively managed oak forests. We used tree crown area (CA ap ) measurements from very high-resolution (30 cm) orthorectified small format digital aerial photographs as the predictive variable. The CA ap accuracy was validated using field measurements of the crown area (CA f ). Allometric relationships between: (a) CA ap versus AGB, and (b) CA ap versus WSC had a high significance level (R 2 > 0.91, p < 0.0001). This approach shows that it is possible to obtain sound biomass estimates as a function of the crown area derived from digital small format aerial photographs.