The effect of slope aspect on vegetation attributes in a mountainous dry valley, Southwest China

Abstract

Slope aspect plays a critical role in influencing vegetation pattern in semiarid area. The dry valleys of the Hengduan Mountains Region, southwestern China, are striking geographical landscape, suffering from severe ecological degradation. Here, we comprehensively investigated how slope aspect affects vegetation attributes in one of these valleys- the dry valley in the upper reaches of Min River. Three sites were selected along the valley and we quantitively examined the vegetation difference between slope aspects at the whole valley scale and each site level. We found significant vegetation differences between slope aspects in species composition, vegetative structure, and biodiversity pattern, which were in accordance with the observed significant difference in soil nutrient. Generally, north-facing slopes are associated with higher biomass, coverage and height, and species diversity than south-facing slopes. We also found between-aspect differences varied among the study sites, resulting in increased biomass, height, and β diversity differences, decreased density and coverage differences, and opposite trend observed in α diversity at relatively wet site. In conclusion, slope aspect had significant effect on vegetation attributes, which was significantly influenced by local climate (aridity) in terms of both strength and direction depending on the specific attributes investigated.

Woody Species Composition, Plant Communities, and Environmental Determinants in Gennemar Dry Afromontane Forest, Southern Ethiopia

“…The amount of incident solar radiation can also affect the temperature of the soil and air at the ground's surface [ 49 ]. Soil temperature has a significant impact on plant growth and establishment (such as seed germination and root growth) [ 52 ]. Forest structures on northeast and south-west facing slopes are expected to differ due to differences in the duration and intensity of incoming solar radiation [ 40 ].…”

Shifts and plasticity of plant leaf mass per area and leaf size among slope aspects in a subalpine meadow

“…Slope aspect is an important topographic factor that underlies the variation of vegetation composition and attributes and contributes to the substantial heterogeneity of landscape and high species diversity at the local scales (Li et al., 2011 ; Sidari et al., 2008 ; Singh, 2018 ; Warren, 2008 ; Warren II, 2010 ; Yang et al., 2020 ). For example, the previous studies have shown a higher richness and coverage of forbs species on north‐facing slopes (NFS) compared with south‐facing slopes (SFS; Li et al., 2011 ).…”

Applying Spatial Analysis to Create Modern Rich Pictures for Grassland Health Analysis

“…Aspect indicates the orientation of a slope to the sun, therefore suggesting the level of incident sunlight radiation on it, while altitude is a highly influential topographic attribute on the abiotic factors of an environment [40]. Aspects and altitude determine the microclimate of an area, and thus play an important role in vegetation patterns of productivity, species composition and biodiversity [41][42][43], and soil chemical, physical, and biological parameters [44][45][46], all of which are essential attributes used to assess grassland health, especially in a highly heterogeneous environment such as LUMGS.…”