关键词: 沙漠生态系统, 生态适应能力, 解剖结构, 生理特性, 防护林

Abstract:

The establishment of shelter forests in the northeastern region of Ulan Buh Desert is a crucial ecological barrier to protect agricultural productivity within the eastern Hetao Plain. However， the lack of attention towards scientific research on artificial afforestation has resulted in a decline tendency in many shelter forest systems. The investigation of ecological adaptability of indigenous tree species after artificial cultivation was a crucial approach to guide the establishment and sustainable management of plantations. In order to further investigate the ecological adaptability of native tree species in Ulan Buh Desert after artificial cultivation， three native tree species： Ammopiptathus mongolicus， Zygophyllum xanthoxylon and Prunus mongolica were used as materials. By measuring the epidermal morphology， anatomical structure， and physiological indices of functional leaves， in conjunction with local meteorological data， the adaptive mechanisms of these plants to arid desert environments were clarified. The results showed that each of three plants exhibited distinct adaptations to arid desert environment in different ways. A. mongolicus enhanced light exposure and photosynthetic efficiency by augmenting leaf area， strengthened leaf mechanical defenses through dense epidermal hairs and well-developed cuticle， reduced light-induced damage and water transpiration， and maintained cellular water balance to minimize lipid peroxidation. The leaves of P. mongolica were clustered， by increasing number of leaves， the light receiving area was increased and the photosynthetic efficiency was improved， and by curling the leaves to avoid strong light burns， the water transpiration was reduced and the cell water balance was maintained by specializing the stomatal position（all the stomata were distributed on the lower surface of the leaves）， developed vascular bundles and rich mucous cells and crystal structures， and reduced cell membrane lipid peroxidation. The leaves of Z. xanthoxylon showed a cylindrical strip structure. By reducing the wind resistance， the probability of wind-sand flow damage to the leaves was reduced. The antioxidant enzyme activity and osmotic adjustment substance content in leaves was enhanced by physiological metabolic regulation， and the balance of cell water and reactive oxygen species metabolism was maintained. These findings suggested the different adaptation strategies adopted by the three plants in response to the desert environment， and provided the new ideas for introduction and domestication of native tree species in the northeastern Ulan Buh Desert.

Key words: desert ecosystem, ecological adaptability, anatomical structure, physiological characteristics, protection forest