Quantifying the Effect of Land-cover Change on the Endangered Farmland Green Treefrog (Zhangixalus arvalis) in an Agricultural Landscape: Implications for Conservation.

Habitat loss and fragmentation have a significant negative effect on amphibian species, particularly those with specialized habitat requirements. The endangered farmland green treefrog (Zhangixalus arvalis) primarily inhabits woodlands of agricultural landscapes in central Taiwan. Recently, due to increased demands for pineapple products, many woodlands, particularly bamboo plantations, were converted to pineapple fields. This study aimed to quantify the effect of habitat loss and fragmentation on Z. arvalis due to changes in land cover in an agricultural landscape. The study area contained 34,243 50 m × 50 m grids. In 2006 and 2014-2015, we used acoustic surveys to survey the occurrence of Z. arvalis in each grid. We obtained satellite images of the study area for 2006 and 2014, and we assigned the land-cover type of each grid to one of the following six types: woodland, brushland, cropland, bareland, manmade structures and water body. We examined whether Z. arvalis preferred a certain land-cover type by comparing the proportion of cover types available and the proportion of cover types used by the frogs. Furthermore, we used occurrence records for 2006 and 2014-2015 and applied the Maximum Entropy Model to predict suitable habitat for the respective years. We mapped the loss of suitable habitat and used six indices to quantify habitat fragmentation within the 8 years. We also tested the prediction that the occupancy rate of Z. arvalis in different-sized habitat patches was a function of patch size. Zhangixalus arvalis exhibited a strong preference for woodland, but avoided cropland and manmade structures. From 2006 to 2014-2015, the suitable habitat decreased 4.1%, and all six indices showed an increase in habitat fragmentation. The occupancy rate of different-sized woodland patches was positively correlated with patch size. Mapping suitable habitat and identifying the potential gaps in functional habitat connectivity can be used to guide effective measures for conserving Z. arvalis.

Regional scale high resolution δ18O prediction in precipitation using MODIS EVI.

The natural variation in stable water isotope ratio data, also known as water isoscape, is a spatiotemporal fingerprint and a powerful natural tracer that has been widely applied in disciplines as diverse as hydrology, paleoclimatology, ecology and forensic investigation. Although much effort has been devoted to developing a predictive water isoscape model, it remains a central challenge for scientists to generate high accuracy, fine scale spatiotemporal water isoscape prediction. Here we develop a novel approach of using the MODIS-EVI (the Moderate Resolution Imagining Spectroradiometer-Enhanced Vegetation Index), to predict δ(18)O in precipitation at the regional scale. Using a structural equation model, we show that the EVI and precipitated δ(18)O are highly correlated and thus the EVI is a good predictor of precipitated δ(18)O. We then test the predictability of our EVI-δ(18)O model and demonstrate that our approach can provide high accuracy with fine spatial (250×250 m) and temporal (16 days) scale δ(18)O predictions (annual and monthly predictabilities [r] are 0.96 and 0.80, respectively). We conclude the merging of the EVI and δ(18)O in precipitation can greatly extend the spatial and temporal data availability and thus enhance the applicability for both the EVI and water isoscape.

Elevation increases in moth assemblages over 42 years on a tropical mountain.

Physiological research suggests that tropical insects are particularly sensitive to temperature, but information on their responses to climate change has been lacking-even though the majority of all terrestrial species are insects and their diversity is concentrated in the tropics. Here, we provide evidence that tropical insect species have already undertaken altitude increases, confirming the global reach of climate change impacts on biodiversity. In 2007, we repeated a historical altitudinal transect, originally carried out in 1965 on Mount Kinabalu in Borneo, sampling 6 moth assemblages between 1,885 and 3,675 m elevation. We estimate that the average altitudes of individuals of 102 montane moth species, in the family Geometridae, increased by a mean of 67 m over the 42 years. Our findings indicate that tropical species are likely to be as sensitive as temperate species to climate warming, and we urge ecologists to seek other historic tropical samples to carry out similar repeat surveys. These observed changes, in combination with the high diversity and thermal sensitivity of insects, suggest that large numbers of tropical insect species could be affected by climate warming. As the highest mountain in one of the most biodiverse regions of the world, Mount Kinabalu is a globally important refuge for terrestrial species that become restricted to high altitudes by climate warming.