A Protocol for Sampling Ecohydrological Traits in Nepal's Terai Arc Landscape

Abstract

The Terai Arc Landscape (TAL) of Nepal is a global priority conservation area for the Bengal Tiger (Panthera tigristigris). The Bengal Tiger faces numerous threats to its survival, including a decrease in prey availability as a result of the degradation and loss of critical habitats such as grasslands and wetlands. Fluctuating groundwater tables can potentially contribute to the loss of these habitats as grasslands thrive with shallower groundwater levels. The potential impacts of human development and climate change on groundwater in the region necessitates the investigation on the dynamic relationship between hydrologic and vegetation processes. This Master's thesis forms a part of the "Save the Tiger! Save the Grasslands! Save the Water!" (Tiger) project that aims to contribute to the conservation efforts of tiger habitats in the TAL through recognizing the significance of ecohydrology and its impact on these crucial tiger habitats. The primary objective of this research is to develop a protocol to facilitate the systematic collection of consistent and reliable data on Leaf Area Index (LAI), Fractional Vegetation Cover (FVC), and Surface Soil Moisture (SSM) - key parameters that describe ecohydrological relationships. Moreover, a secondary objective is investigated, utilizing the data acquired through implementation of the developed protocol to validate satellite products to explore the potential of upscaling in-situ data. The protocol demonstrated its ability to capture consistent and reliable data for LAI and FVC across various vegetation types, showing potential for application across different regions in the TAL. Additionally, the study explored the viability of a smartphone-based LAI method, the PocketLAI, which proved to be a feasible alternative to the more established and high-cost AccuPAR-LP80, albeit requiring further investigation on the effect of specific smartphone models and LAI retrieval. While the protocol captured consistent SSM data, improvements are necessary to enhance the reliability of these measurements. The validation of satellite products revealed significant relationships with in-situ LAI and FVC. Despite largely underestimating LAI and FVC values, the results have important implications for monitoring patterns of these parameters across the TAL. Further iterations of the protocol, implemented across different fieldwork campaigns within The Tiger Project, are crucial for establishing a robust protocol. Such a comprehensive protocol will have invaluable implications for conservation efforts towards tiger habitats and form a fundamental platform for future research and analysis in the TAL.