Do aeolian deposits and sand encroachment intensity shape patterns of vegetation diversity and plant functional traits in desert pavements?  

作　　者：M'hammed BOUALLALA Souad NEFFAR Lyès BRADAI Haroun CHENCHOUNI 

机构地区：[1]Laboratory of Saharan Natural Resources,Faculty of Sciences and Technology,University of Ahmed Draia,Adrar 01000,Algeria [2]Department of Nature and Life Sciences,Faculty of Exact Sciences and Nature and Life Sciences,University of Tebessa,Tebessa 12002,Algeria [3]Laboratory Water and Environment,University of Tebessa,Tebessa 12002,Algeria [4]Laboratory of Saharan Bioresources Preservation and Valorization,Faculty of Nature and Life Sciences,University of Kasdi Merbah,Ouargla 30000,Algeria [5]Department of Forest Management,Higher National School of Forests,Khenchela 40000,Algeria [6]Laboratory of Natural Resources and Management of Sensitive Environments,University of Oum-El-Bouaghi,Oum-El-Bouaghi 04000,Algeria

出　　处：《Journal of Arid Land》2023年第6期667-694,共28页干旱区科学（英文版）

摘　　要：The effects of sand encroachment on composition,diversity,and functional patterns of vegetation in drylands are rarely studied,and yet addressing these aspects is important to deepen our understanding of the biodiversity conservation.This study aimed to investigate the effect of sand encroachment on plant functional biodiversity of desert pavements(gravel deserts)in the Sahara Desert of Algeria.Plants were sampled and analyzed in three desert pavements with different levels of sand encroachment(LSE)and quantity of aeolian deposits(low,LLSE;medium,MLSE;and high,HLSE).Within the sample-plot area(100 m^(2)),density of every plant species was identified and total vegetation cover was determined.Plant taxonomic and functional diversity were analyzed and compared between LSE.Result showed that 19 plant species in desert pavements were classified into 18 genera and 13 families.Asteraceae and Poaceae were the most important families.The species Anabasis articulata(Forssk)Moq.characterized LLSE desert pavements with 11 species,whereas Thymelaea microphylla Coss.&Durieu ex Meisn.and Calobota saharae(C&D)Boatwr.&van Wyk were dominant species of desert pavements with MLSE(14 species)and HLSE(10 species),respectively.The highest values of species richness and biodiversity were recorded in desert pavements with MLSE,while low values of these ecological parameters were obtained in desert pavements with HLSE.Desert pavements with LLSE were characterized with the highest values of species abundances.Plant communities were dominated by chamaephytes,anemochorous,arido-active,and competitive stress-tolerant plants.The increase in LSE along the gradient from LLSE to HLSE induced significant changes in plant community variables including decreases in plant density,plant rarity,lifeform composition,morphological type,and aridity adaptation.Desert pavements with HLSE favor the degradation of vegetation and trigger biodiversity erosion.

关 键 词：desert pavements hot and arid rangeland plant diversity land degradation sand encroachment plant functional trait Sahara Desert 

分 类 号：Q948[生物学—植物学]