Functional vegetation community responses to soil and topographic factors in the Loess Plateau of China

Abstract

Given the developmental program outlined in United Nations Sustainable Development Goal 15 (Life on Land) and the to effectively address the challenge of biodiversity decline while mitigating the adverse effects of climate change, particularly drought, on terrestrial forest ecosystems, a fundamental reorientation of global forest restoration paradigms is warranted. It is imperative to move beyond a narrow emphasis on expanding forest area and instead prioritize the enhancement of biodiversity and functional attributes within these ecosystems. However, the differential response mechanisms of forest ecosystem functional communities and main plant functional types (PFTs) to environmental factors, especially soil and topography, remains unclear, especially at plant level. Here, we divided the functional communities of 93 sites in the study area into seven groups through Two‐way indicator species analysis (TWINSPAN), and studied the different functional communities, namely dynamic succession, species richness, and PFT compositional differences. We also analyzed the various PFTs and functional community response mechanisms to soil and topographic factors using canonical correspondence analysis (CCA). The main results were as follows: (1) With the successional stages of PFTs, vegetation diversity across multiple functional communities inceased, tree and shrub proportions and importance increased, while herbs decreased. (2) From the arid and barren areas (i.e., G2), to the humid and fertile areas (i.e., G6 and G7), various compositional PFT differences, and their responses to soil and topographic factors, were found, namely, xerophytic, annual and biennial species gradually changed to mesophytic, hygrophytic, and perennial species (richness increased 6.94 ~ 27.33%, important value (IV) increased 8.73 ~ 29.45%) for shrubs and herbs. (3) Functional communities in various successional stages display distinct sensitivities to soil and topographic factors, as evidenced by a notable increase in the richness and IV of deciduous broad‐leaved tree species, rendering their communities more responsive to SOC and AS, whereas evergreen coniferous trees (e.g., Pinus tabuliformis Carr.) were sensitive to altitude (AL) and exhibited a tendency to transition from plantations to natural secondary forests predominantly at higher altitudes (above 1200 m). Our findings suggest that site conditions influence scenarios, and that different PFT responses and adjustments to soil and topography factors affect whole functional community dynamic succession processes, which can profoundly impact forest ecosystem function predictions based on PFT changes in the Loess Plateau of China.

Species of the Poaceae family suitable for Andean livestock farming in the Peruvian Andes reported in GBIF and local studies

“…to the complex and rugged topographic factor, coupled with signifi cant latitudinal and altitudinal gradients with physical and chemical soil properties of low agro-ecological value and low nitrogen availability [37][38][39][40].…”

Developmental Dynamics and Driving Factors of Understory Vegetation: A Case Study of Three Typical Plantations in the Loess Plateau of China

“…occur mainly in the middle and late stage (stand age > 20) of vegetation restoration (Table 7). Combined with the high fluctuation in understory vegetation species diversity of PP in Section 4.1, with the sudden stand density decline, the difference in the microclimates (e.g., heat radiation, air humidity, and temperature) in the forest caused by EL has become the new main driving factor (Figure 7) [33].…”

“…Stand structure can determine the microclimatic conditions, and affect species richness and understory regeneration [32]. Soil and topographical factors specifically affect vegetation community assembly processes through the hydrological and nutrient cycles, as well as microbial community changes [11,33]. Moreover, stand age has always been an important factor, especially regarding light heterogeneity [34].…”

Effects of Geomorphic Spatial Differentiation on Vegetation Distribution Based on Remote Sensing and Geomorphic Regionalization

“…At present, most studies are about the response of vegetation distribution to topographic factors such as elevation, slope, and slope direction, mainly focusing on the vertical distribution of large-scale vegetation belts. However, there are few studies on the effect of detailed geomorphic types on vegetation coverage [15][16][17][18]. Therefore, there is an increasing need to quantitatively assess the impact of different geomorphic types on vegetation coverage, which is a new research focus.…”