Assessment of ecosystem resilience to hydroclimatic disturbances in India

Abstract

Recent studies have shown an increasing trend in hydroclimatic disturbances like droughts, which are anticipated to become more frequent and intense under global warming and climate change. Droughts adversely affect the vegetation growth and crop yield, which enhances the risks to food security for a country like India with over 1.2 billion people to feed. Here, we compared the response of terrestrial net primary productivity (NPP) to hydroclimatic disturbances in India at different scales (i.e., at river basins, land covers, and climate types) to examine the ecosystems' resilience to such adverse conditions. The ecosystem water use efficiency (WUE : NPP/Evapotranspiration) is an effective indicator of ecosystem productivity, linking carbon (C) and water cycles. We found a significant difference (p < .05) in WUE across India at different scales. The ecosystem resilience analysis indicated that most of the river basins were not resilient enough to hydroclimatic disturbances. Drastic reduction in WUE under dry conditions was observed for some basins, which highlighted the cross-biome incapability to withstand such conditions. The ecosystem resilience at land cover and climate type scale did not completely relate to the basin-scale ecosystem resilience, which indicated that ecosystem resilience at basin scale is controlled by some other ecohydrological processes. Our results facilitate the identification of the most sensitive regions in the country for ecosystem management and climate policy making, and highlight the need for taking sufficient adaptation measures to ensure sustainability of ecosystems.

Response of Ecosystem Water Use Efficiency to Drought over China during 1982–2015: Spatiotemporal Variability and Resilience

“…The value of Rd can be classified into four categories [29]: if Rd was greater than or equal to 1, the grid cell was considered to have resilience and it meant that the ecosystem can sustain its productivity…”

“…The ecosystem resilience was considered as the ability of an ecosystem which could resist external disturbances (such as drought) and sustain the same structure and functions under changing conditions [19,49]. In this study, we used a dimensionless index (R d ) defined by Sharma et al [29,50] to quantify terrestrial ecosystem resilience to drought on a per-pixel basis:…”

“…The terrestrial ecosystem resilience represents the ability of an ecosystem to absorb disturbances from hydro-climate (e.g., drought) and to sustain or recover its structure and functions with ever-changing environments [28]. A resilient ecosystem could sustain or increase WUE to e nsure its productivity under water shortage conditions due to drought [29]. Ponce Campos et al (2013) explored the relationship between WUE and drought during the drought in the early 21st century and found that Australian and North American ecosystems had strong biome-scale resilience according to increased WUE in the dry year [19].…”

“…Ponce Campos et al (2013) explored the relationship between WUE and drought during the drought in the early 21st century and found that Australian and North American ecosystems had strong biome-scale resilience according to increased WUE in the dry year [19]. Sharma et al (2017) examined ecosystem resilience at the river basin scale in India during 2000-2014 based on the MODIS (Moderate Resolution Imaging Spectroradiometer) dataset and indicated that most basins in India were not resilient to disturbances [29].…”

The Transferability of Random Forest in Canopy Height Estimation from Multi-Source Remote Sensing Data

“…The collected data were manually examined to ensure that the coverage of cloud and snow was lower than 10%. Land cover classification map was obtained from 500-m MODIS land cover data (MCD12Q1) [37], which has been used in many studies to stratify vegetation types [38,39]. The terrain information was represented by the 30-m Shuttle Radar Topography Mission (SRTM) digital terrain model (DTM) data collected from the United States Geological Survey.…”