青藏高原高寒草甸门源草原毛虫取食偏好及其与植物C、N含量的关系

发布时间：2019-01-22 18:42

【摘要】：草食性昆虫对不同植物物种的取食存在偏好,这种取食偏好可能受其自身对蛋白质和碳水化合物的需求及二者平衡的调节。以青藏高原高寒矮嵩草草甸31种常见植物及门源草原毛虫为对象,通过饲喂实验,研究了草食性昆虫对不同物种和不同功能群植物的取食偏好,及其与植物叶片C、N含量和C∶N之间的关系。在31种植物中,门源草原毛虫对19种植物进行了取食,尤其对矮嵩草、红棕薹草、藏异燕麦和垂穗披碱草四种植物表现出强烈的取食偏好,而对另外12种植物未进行任何取食。在物种水平上,门源草原毛虫取食量与植物叶片N含量呈显著负相关,与叶片C∶N呈正相关。从功能群水平上看,门源草原毛虫对莎草类的取食偏好最大,而对豆科植物取食偏好最低;相应地,莎草类植物叶片N含量最低、C∶N最高,而豆科植物叶片N含量最高、C∶N最低。因此,即使在土壤有效氮匮乏、植物生长受氮素限制的高寒草甸生态系统,植物体内N含量的增加也可能不利于草食性昆虫的取食。门源草原毛虫对优势植物矮嵩草和垂穗披碱草的取食对高寒矮嵩草草甸物种共存和生物多样性维持可能具有重要的作用。
[Abstract]:Herbivorous insects have a preference for different plant species which may be regulated by their own demand for protein and carbohydrates and their balance. Taking 31 common plants of Kobresia humilis meadow in Qinghai-Xizang Plateau and Caterpillar of Mengyuan grassland as subjects, the feeding preference of herbivorous insects to different species and different functional groups of plants was studied. The relationship between N content and C: N. Among 31 species of plants, 19 species were fed by Mengyuan grassland caterpillars, especially for Kobresia humilis, Carex rubrum, Avena sativa and Elaeagnus capsicus, but not any other 12 species. At the species level, there was a significant negative correlation between the amount of caterpillar feeding and N content in plant leaves, and a positive correlation between the feeding amount of Caterpillar and the leaf C: n content. At the level of functional group, the preference of Caterpillar for seagrass was the largest, and the preference for legume was the lowest. Accordingly, the content of N in leaves of Cyperidae was the lowest, that of C _ (1) N was the highest, that of leaves of legume was the highest, and that of C _ (10) N was the lowest. Therefore, even in the alpine meadow ecosystem where soil available nitrogen is deficient and plant growth is limited by nitrogen, the increase of N content in plants may not be conducive to foraging of herbivorous insects. The feeding of Caterpillar on dominant plants Kobresia humilis and Elaeagnus perpendiculata may play an important role in species coexistence and biodiversity maintenance in Alpine Kobresia humilis meadow.
【作者单位】：北京林业大学自然保护区学院;中国科学院地理科学与资源研究所生态网络观测与模拟重点实验室;
【基金】：中央高校基本科研业务费专项资金(TD-JC-2013-1) 国家自然科学基金面上项目(31270503)
【分类号】：S812

【参考文献】