Phenological variation of alpine grasses (Gramineae) in the northeastern Qinghai-Tibetan Plateau, China during the last 20 years

Abstract

The Qinghai鄄Tibet Plateau (QTP) is usually regarded as an ideal place to study the response of natural ecosystems to climate change because this mountainous region supports one of the most fragile environments within the global ecosystem. After the QTP experienced a distinct warming in recent decades, scientists have realized that a remarkable variation in vegetation in the QTP could potentially result from climate change. In this paper, the temporal variation of phenology for the alpine Gramineae was analyzed for the dates of the onset of growth in spring, blossoming, and withering from 1988 to 2010 based on the observations from five in鄄situ sites in the northeastern QTP. Additionally, the relationships between temperature or precipitation and the duration of the growth period for alpine Gramineae were investigated using the stepwise regression and partial correlation analysis. Seasonal trends were found to be advancing significantly in the last20 years in the southern QTP, which includes the Three鄄Rivers Source Area for the dates of onset, blossoming and withering of grasses. Specifically, the trendsare-4d / 10a for onset,-13d / 10a for blossoming, and-9 d / 10a for withering in the Qumalai fescue grassland, all of which are statistically significant (P < 0.01) .Additionally, the Haibei Stipa sareptanavar

MODIS time series contribution for the estimation of nutritional properties of alpine grassland

“…The spatial resolution of MODIS (250 m for red and NIR bands; 500 m or 1 km for other bands) is sufficiently detailed for extensive high altitude grasslands such as those found on the Tibetan plateau and other mountain areas of China, characterised by large extensions and high homogeneity; indeed, most of the studies which use MODIS data to estimate forage quality in alpine grassland environments have been conducted in these sites [e.g. Zha et al, 2005;Gao et al, 2009;Zhang et al, 2011;Mao et al, 2012;Cong et al, 2013;Liang et al, 2013;Zhang et al, 2013;Xu et al, 2014]. Instead, in the European Alps, grasslands are typically located in the alpine zone, which is generally fragmented between lower woody and higher rocky habitats, with a consequent higher spatial heterogeneity (at these elevations large uplands are uncommon, especially in the Western Alps).…”