Altitudinal patterns of plant diversity, cover, and life forms in a warm arid mountain: Insights from Sierra de Velasco, Argentina  

作　　者：Sofia V.LIZARRAGA Omar VARELA Julieta CARILLA 

机构地区：[1]Instituto de Ambientes de Montana y RegionesÁridas(IAMRA),Universidad Nacional de Chilecito(UNdeC),9 de Julio 22,CP F5360CKB,Chilecito,La Rioja,Argentina [2]Instituto de Ecologia Regional(IER),Universidad Nacional de Tucuman(UNT)-Consejo Nacional de Investigaciones Cientificas y Tecnicas(CONICET),CC34 CP4107,Tucumán,Argentina

出　　处：《Journal of Mountain Science》2025年第3期873-887,共15页山地科学学报(英文)

摘　　要：Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change.

关 键 词：Elevation gradient Plant diversity Life forms Arid mountains Diversity pattern Climatic drivers 

分 类 号：Q948[生物学—植物学] P467[天文地球—大气科学及气象学] P941.76