[Research advances in shrub dendroecology]

Abstract

The ecological value of shrub-ring data has received more and more attention. The tree-ring data of shrub species have been increasingly used to reveal growth dynamics of regional shrub vegetation and its sensitivity to climate change. Up to now, nearly 70 species of shrubs have been used in the studies of shrub dendrochronology, which considerably broadened the traditional tree-ring research network, enriched the research scope and object of dendrochronology, and certainly with great significance in revealing the characteristics of regional climate fluctuation and annual dynamics of structure, function and service for shrubland ecosystems. In this study, we systematically collected dendrochronological studies based on shrub species during the 1996-2021, and reviewed research progress in four main subfields (physiology, climatology, ecology and hydrology) in dendrochronology for shrub species. The characteristics of shrub growth and xylem anatomy under different environmental stresses were expounded. The main limiting factors for shrub growth in different climatic conditions and the history of regional climate fluctuations based on shrub-ring data were revealed. The individual growth and population dynamics of shrub species driven by climate and the changes in ecosystems caused by non-climatic factors were assessed, and the reconstructions of regional hydrological histories were compiled using tree-ring data of shrub species. Under the context of global warming, dendrochronological studies of shrub species in China should pay more attention to the responses of shrub species radial growth to drought stress under different moisture conditions in the semi-arid and arid regions and the transforming feature of distribution pattern and climate response sensitivity for shrub species under the background of climate change.

Keywords: anatomy of xylem; climate change; ecological response; hydrologic response; shrub ring.