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

Accueil du site → Doctorat → Chine → 2019 → Canopy Rainfall Interception Characteristics of Grassland Community in Loess Hilly-Gully Region and Its Dominant Species in Response to Simulated Rainfall

Northwest A&F University (2019)

Canopy Rainfall Interception Characteristics of Grassland Community in Loess Hilly-Gully Region and Its Dominant Species in Response to Simulated Rainfall

熊沛枫;

Titre : Canopy Rainfall Interception Characteristics of Grassland Community in Loess Hilly-Gully Region and Its Dominant Species in Response to Simulated Rainfall

Auteur : 熊沛枫;

Grade : Doctoral Dissertation 2019

Université : Northwest A&F University

Résumé partiel
Rainfall,the only source of soil moisture,is a key factor in controlling plant growth and distribution in the semiarid loess-hilly region.Vegetation canopy interception is the primary link of rainfall redistribution,which directly affects land surface eco-hydrological processes and the water availability of plant.Quantifying rainfall interception and utilization characteristics of grassland communities and their dominant species is helpful to understand the internal influencing mechanism of canopy interception and the eco-hydrological effects of vegetation restoration.In this study,the abandoned grassland communities and their main species were selected.We systematically measured the seasonal changes of canopy storage capacity and community characteristics,the surface storage characteristics and morphological traits of main species,and leaf photosynthesis and water potential responses of dominant species to simulated rainfall.The main results are as follows :(1)Leaf wettability had obvious inter-species differences and was an important indicator in affecting leaf and plant surface storage.A total of 68 common species in grassland communities were investigated.Leaf contact angles were between 27.3°and 133.4°,and the variation coefficient was negatively correlated with contact angle(r=-0.56 ;p<0.001).Leaf wettability was affected by leaf side,family,leaf age and growth period,whereas the life form and slope aspect did not show significant effects.There were 47 species having higher wettability in adaxial surface than the abaxial,and the differences were significant in 23 species(p<0.05).Gramineous and leguminous species were more unwettable than compositae and rosaceous species.New leaves were more unwettable than old leaves.Surface wettability increased from May-June to July-August period.Leaf surface storage was negatively correlated with adaxial(r=-0.42)and abaxial contact angles(r=-0.43).Plant surface storage was negatively correlated with adaxial contact angle(r=-0.42),whereas it had approximate correlation with abaxial contact angle(r=-0.35 ;p=0.073).Leaf wettability is an important plant trait for comparing species differences in rainfall interception performance.The species and seasonal variations of leaf wettability should be taken into account when accurately predicting rainfall interception.(2)Leaf area and wettability index were suitable indicators for judging plant storage capacity.A total of 55 common species in grassland communities were investigated.Plant surface storage ranged from 0.12~1.26 g g-1,and Glycyrrhiza uralensis and Leymus secalinus had the highest and lowest values,respectively.Rosaceous species had the highest surface storage,followed by leguminous and compositae species,and the gramineous species were the lowest.Leaf storage ratio ranged from 40.2~93.2%,and Glycyrrhiza uralensis and Chenopodium album had the highest and lowest values,respectively.

Mots clés : rainfall interception; leaf area; coverage; aboveground biomass; photosynthetic physiology; leaf water potential;

Présentation (CNKI) ->https://oversea.cnki.net/KCMS/detai...

Page publiée le 14 octobre 2020, mise à jour le 25 novembre 2021