Influence of Slope Aspect on Plant Community Composition and its Implications for Restoration of a Chinese Mountain Range

Abstract

Excessive human disturbance (e.g., overgrazing, deforestation) has degraded the environment in the Qilian Mountains in China. Vegetative restoration is likely to be a crucial tool to restore these biologically significant habitats, but it is impossible to achieve this goal if the baseline plant community composition and its variation with local environmental conditions were not understood fully. To assess plant community composition by slope aspect, four different aspects -south-facing slope (SF), southwest-facing slope (SW), northwest-facing slope (NW), and north-facing slope (NF) -were surveyed on three almost non-degraded mountains. The results showed that each slope aspect has different abiotic environments. From SF to NF, soil water content has an increasing trend, but it shows no difference between SF and SW; and daily soil temperature and pH have a decreasing trend, while the former shows no difference between SF and SW, and SW and NW; and the latter shows no difference between SW and NW; and soil organic carbon was significantly increased, but soil bulk density was significantly decreased. Herbaceous plants were dominant on SF, SW, and NW, and trees (Picea crassifolia) were dominant on NF. From SF to NW, the dominant herbaceous plants were Agropyron cristatum and Stipa grandis, Agropyron cristatum and Carex aridula, and Kobresia humilis and Carex crebra, respectively, while on NF they were Carex spp. and Polygonum macrophyllum. The baseline survey points to the need to consider underlying patterns in abiotic conditions when planning restoration programs in these degraded mountain habitats, and to select native plants similar to the original vegetation. The survey provides a vital milestone for the development of policy-based funding initiatives and for ongoing vegetation monitoring during restoration to assess if these vegetative targets have been met.

Effects of Vegetation Cover/Land Use and Slope Aspect on Surface Soil Properties Near the Copper Smelter Factory in Murgul, Turkey

“…While soil organic matter content of black alder increased from south (1.49%) to north (2.66%) facing slopes (p = 0.02), that of grasslands decreased (p = 0.037). The positive effect of north aspect on organic matter content by also found by Qin et al (2017). Increasing organic matter content in north aspect can be attributed to more organic carbon and more total nitrogen accumulation in the soil because of higher soil water content and less evaporation (Johnson et al, 2011 On the one hand, CaCO3 content of soils was not significantly affected by vegetation cover (p = 0.05) and vegetation cover*slope aspect interaction (p = 0.164), on the other hand, the content decreased from south (2.34%) to north (1.35%) without considering vegetation cover effect (p = 0.008) (Fig.…”

Main ecological and environmental factors affecting forage yield and quality in alpine summer pastures (NW‐Italy, Gran Paradiso National Park)

“…In the alpine area, the effects of climatic variables on vegetation are emphasized by the harsh environmental conditions due to aspect, elevation, and slope. Aspect determines different light exposition, soil moisture, and nutrient availability, thus representing a direct driver of the botanical composition of pastures (e.g., Yanyan et al, 2017) and an indirect factor affecting biomass productivity and its quality (Dongdong et al, 2020). Increasing elevation determines a decrease in air temperature (0.65°C every 100 m) with consequent effects on vegetation productivity (biomass production is generally lower) and growing season length, which is shorter at higher elevation (Dongdong et al, 2020; Liu et al, 2015).…”

Influence of Root Morphology on Ecological Slope Protection

“…In recent years, all kinds of engineering construction activities have been booming, such as expressway and railway engineering, port engineering, energy development and utilization engineering, mineral resource mining, etc., These engineering construction activities will unavoidably form many bare rocky slopes, which not only destruct the vegetations and soil, damage the ecological landscapes but also easily give rise to water and soil loss, and induce geological disasters like collapse, landslide and debris flow [1] [2].…”