Vegetation Dynamics and Climate from A Perspective of Lag-Effect: A Study Case in Loess Plateau, China

Abstract

With global warming, the law of climate change is more and more complex, so it is of great significance to analyze the response mechanism of vegetation change to climate change. The Loess Plateau (LP) is a vulnerable area, but we must explore the mechanism between climate and vegetation for decision-makers to make adequate plans to better govern this population-intensive but ecological-fragile area. Our study analyzed the vegetation variation in a long-term period from 1982 to 2015 and its relationship with precipitation and temperature. We innovatively leverage the weighted time-lag method to detect the different contributions of a specific climatic factor from different months to vegetation growth. Moreover, we used such weighted accumulated climatic factors to find the relationships between precipitation/temperature and different types of vegetation. The main findings are as follows: (i) For different degrees of temperature and precipitation, different vegetation has different performance characteristics in different months from 1982 to 2015. Moreover, precipitation is the major driver of vegetation growth in the LP. (ii) The response of vegetation possesses some time-lag effect on climate and exhibits spatial heterogeneity in the LP, which may be related to the characteristics of different climate zones and different vegetation. (iii) The effect of the same climatic factor on different vegetation accounts for a certain proportion of different months in the LP. Climate possesses a cumulative effect in three months on vegetation and different climatic factors have different time lags to the same vegetation type. It has a complicated interaction between vegetation growth and climate change. This paper uses the weighted time-lag method to investigate the relationship between vegetation growth and climatic factors, whilst considering how the time-lag effect can explain the changes that occur in the process of vegetation growth to a large extent.