RESUMEN
Vegetation responses to climate change are typically nonlinear with varied time effects, yet current research lacks comprehensiveness and precise definitions, hindering a deeper understanding of the underlying mechanisms. This study focuses on the mountain-type Qilian Mountain National Park (QMNP), investigating the characteristics and patterns of these nonlinear time effects using a generalized additive model (GAM) based on MODIS-NDVI, growing season temperature, and precipitation data. The results show that 1) The time effects of climate change on vegetation exhibit significant spatial variations, differing across vegetation types and topographic conditions. Accounting for optimal time effects can increase the explanatory power of climate on vegetation change by 6.8 %. Precipitation responses are mainly characterized by time-lag and time-accumulation effects, notably in meadows and steppes, while temperature responses are largely cumulative, especially in steppes. The altitude and slope significantly influence the pattern of vegetation response to climate, particularly in areas with high altitudes and steep slopes. 2) There is a significant nonlinear relationship between vegetation growth and both precipitation and temperature, with the nonlinear relationship between precipitation and vegetation being stronger than that with temperature, particularly in the western and central regions of the park. Different vegetation types exhibit significant variations in their response to climate change, with deserts and steppes being more sensitive to precipitation. 3) Precipitation is the primary driver of vegetation change in the QMNP, particularly for high-elevation vegetation and herbaceous vegetation. The complex temporal patterns of vegetation response to climate change in the QMNP not only deepen the understanding of the intricate relationship between regional vegetation and climate variability but also provide a methodological reference for global studies on vegetation responses to climate change.
RESUMEN
It is still challenging to develop anode materials with high capacity and long cycling stability for lithium-ion batteries (LIBs). To address such issues, herein, for the first time, we present a three-dimensional and freestanding ReS2/graphene heterostructure (3DRG) as an anode synthesized via a one-pot hydrothermal method. The hybrid shows a hierarchically sandwich-like, nanoporous, and conductive three-dimensional (3D) network constructed by two-dimensional (2D) ReS2/graphene heterostructural nanosheets, which can be directly utilized as a freestanding and binder-free anode for LIBs. When the current density is 100 mA g-1, the 3DRG anode delivers a high reversible specific capacity of 653 mAh g-1. The 3DRG anode also delivers higher rate capability and cycling stability than the bare ReS2 anode. The markedly boosted electrochemical properties derive from the unique nanoarchitecture, which guarantees massive electrochemical active sites, short channels of lithium-ion diffusion, fast electron/ion transportation, and inhibition of the volume change of ReS2 for LIBs.
