天山野果林的发生、演变与气候因素的关系

通过对天山伊犁河谷地野果林的分布状况调查,并结合多年气象资料,对天山伊犁河谷地野果林的发生、演替与气候因素的关系进行了分析。结果表明,天山伊犁河谷地野果林是在干旱荒漠地带山地中出现的由西风气流营造的“地中海性”阔叶落叶林类型。它的发生、演变和分布与当地丰富的降水量、鲜明的冬季逆温层以及免于寒潮侵袭的地形等特殊的生态因子密切相关。它是珍稀的山地“孑遗”群落,是天山山地第三纪古温带阔叶落叶林成分与北方森林草甸成分相结合的产物。与中亚西天山野果林有明显区别。该河谷地是世界栽培落叶果树的重要起源地之一,也是世界上稀有的生物多样性天然基因库。

Relationship of the Occurences and Evolutions of Wild-Fruit Forests with Climatic Factors in the Tianshan Mountain

The distributions of wild-fruit forests in Yili River Valley of the Tianshan Mountain were investigated and the relationships of the occurrence and evolutions of the forests with climatic factors in the valley were accordingly analyzed in light of the multi-year climatic data.The results show that wild-fruit forests in Yili River Valley of the Tianshan Mountain are the "Mediterranean" broadleaf forests occurring in mountainous lands of arid desert regions under the influence of prevailing westward air currents.Their occurrences and evolutions and distributions closely relate to such ecological factors as abundant local rainfall,clear inversion layer in winter and landforms exempt from the impact of cold wave.They are precious and rare relict communities as well as the products resulting from the combination of the components of the teriary paleo-temperate broadleaf forests in the Tianshan Mountain and the forest meadows in northern China,and much differ from the wild-fruit forests of the Tianshan Mountain in the western part of central Asia.They are one of the important origins of the deciduous fruit trees planted in the world and a natural gene bak of biodiversity rarely found in the world.