Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Effects of Afforestation on Desert Biome and Its Response in Urumqi

Auteur : 刘鹤佳

Grade : Master 2022

Université : Xinjiang Agricultural University

Résumé partiel
Desert biome is the typical biome representing unique ecosystem in the arid zone of Central Asia,which contains valuable biodiversity resources.Together with the progress of city afforestation project,the green area of barren mountains around city has risen,and may consequently affects desert biomes such as ground plant communities and insect communities.We conducted transects and quadrats surveys in four different barren mountains around Urumqi to study how these biomes were affected.Plant and insect communities were sampled,identified,and compared in three gradients,including Long-term afforestation sites,short-term afforestation sites,and natural habitats.We also discussed the contribution of different environmental factors brought by afforestation to biodiversity,and established database for further evaluating the ecological value of barren mountains.This study was aimed to provide scientific supports for the future sustainable afforestation development and ecological conservation.The main results are as follows :（1）In April and July,2021,herbaceous plant communities were investigated.A total of 132 species were recorded.Species richness among different afforestation gradients were not significantly different,during spring and summer the species richness were Hongyanchi＞Yamalikeshan＞Shuimogou＞Dongshan,their species composition showed a considerable different according to the Jaccard Similarity Index : moderate dissimilarity between long-term and short-term afforestation,natural habitats and short-term afforestation,while extreme dissimilarity between long-term afforestation and natural habitats in Yamalikeshan.At the same time,similar differences among three gradients in Hongyanchi,Shuimogou,and Dongshan were also detected.The dominant species among gradients were also different,for example Artemisia sieversiana was the dominant species in both long-term and short-term afforestation sites in Hongyanchi,but in natural habitats Nanophyton erinaceum was the dominant species.In Shuimogou and Dongshan,long-term afforestation sites were dominate by Geranium linearilobum,while Chenopodium album and Nanophyton erinaceum dominate short-term afforestation and natural habitats,respectively.In Yamalikeshan,Asperugo procumbens,Chenopodium album,and Artemisia spp.were dominate species.These results showed that plants with shade preference gradually take advantage as the progress of afforestation.（2）During April to November,2021,ground insects were sampled using standard pit-fall traps for twice a month.As a result,3756 individuals were collected,and identified to 128 species,which belong to 39 families within 5 orders.The dominant groups were Cuculionidae（11.47%）,Carabidae（28.24%）,and Lygaeidae（49.27%）.The number of individuals declined from April to November.The monthly mean species richness were highest in Yamalikeshan（25.81）,then in Hongyanchi（21.64）,and lowest in Shuimogou-Dongshan（18.45）.Among three afforestation gradients,the species composition were different,with a Jaccard Similarity Index of moderate dissimilarity were observed among all gradients in Yamalikeshan,and extreme dissimilarity among long-term,short-term,and natural habitats for all other mountains.GLM results showed that the main positive factor on the diversity index of insects was nectar resource index（P=0.0188）,and the main negative factor was mean plant community height（P=0.0395）.Tree DBH also showed negative albeit insignificant effect on insect diversity.

Mots clés : Afforestation ;desert biome ;pollinator insects ;diversity;

Présentation (CNKI)