Abstract:

In view of the challenges and urgent problems faced in the health management of old trees, a profound understanding and mastery of the characteristics of old trees are of great significance for improving the level of health management of old trees and scientifically responding to climate change. Based on literature and the author’s research, this paper explains the principles and methods of health management for old trees, reviews the new progress in the research of old trees at home and abroad, and proposes strategies and methods for responding to climate change. The characteristics of old trees mainly include tree species lifespan, tree body size, functional traits, and germplasm. The lifespan of old trees is controlled by tree species and the environment. For trees, lifespan and growth rate of a tree are a contradictory unity of opposites. That is to say, if the growth rate of a tree is very fast, then its lifespan must be very short. Large old trees are more sensitive to environmental changes than small old trees, and functional traits are greatly affected by the environment. An in-depth understanding of the characteristics of old trees and a grasp of the impact of climate change on them are the prerequisites for the correct implementation of old tree health management. Only by making full use of the characteristics of old trees can precise maintenance and rejuvenation of old trees be achieved, and the lifespan of old trees be effectively prolonged. The life history of old trees. Human disturbances, extreme weather and rhizosphere microorganisms and other factors have significant impacts on the health and survival of old trees. With the improvement of the health management level of old trees, the degree of influence of human disturbances on the health and survival of old trees has gradually decreased. The threats to the health of old trees mainly come from environmental stress and the harm of harmful organisms. Especially sudden extreme weather can cause great damage to old trees. The health management of old trees should attach great importance to the control of adverse conditions, fully utilize the ecological elasticity of trees to continuously improve the adaptability of ancient trees to adverse conditions (soil drought and poor fertility), and avoid excessive intervention in the growth environment of ancient trees, such as irrigation, fertilization and other soil management. At the same time, it is necessary to prevent excessive maintenance or long-term exposure of the habitat to adverse conditions, which could cause irreversible damage to the ancient trees. The seasonal rhythm changes brought about by the acceleration of climate change and the frequent disastrous weather such as high temperatures and droughts have led to the widespread growth decline and death of old trees, especially those over a thousand years old, posing great challenges and urgent problems to the health management of old trees, such as the adaptability of old trees (especially large old trees) to climate change and the early warning and emergency response to extreme weather hazards such as hail, strong wind, freezing rain, the healthy management of ancient tree populations, etc. Exploring the functional traits of old trees in response to adverse conditions and their heterogeneity, as well as the key role of the plant microbiome in the response of old trees to adverse stress, and deeply understanding and grasping the characteristics of old trees and their adaptability to climate change have become the keys to accurately judging and solving the hidden dangers affecting the health and safety of old trees.

Key words: old trees, climate change, health management, old tree characteristics, adversity management