In landscapes with high elephant density, trees often exhibit more open canopies with fewer branches and foliage due to browsing pressure. This can result in altered tree morphology, with trees exhibiting stunted growth, multiple stems or unusual branching patterns in response to repeated damage from browsing. The objectives of this research were to (i) model the vegetation structure allometries, (ii) assess the impact of African savannah elephant (Loxodonta africana) herbivory on the vegetation structure and (iii) assess tree cover change and vegetation performance over time in Mana Pools National Park in Zimbabwe. We established 26 plots of 30 x 30 m size. Selection of sampling plots was done following several steps. First, a fish net grid with 30 x 30 m polygons was created and projected on the polygon of Mana Pools National Park. The polygons for exclusion zones were then clipped from the fish net grid using the clip tool in ArcGIS Pro 3.0. Then, selection of sampling plots was done initially by stratified random sampling using the Sampling Design Tool add in for ArcGIS Pro 3.0. Landsat images for the years 2003, 2013 and 2023 were used to assess land use land cover (LULC) time series and to calculate Normalised Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) for the period. A generalised linear model (GLM) was used to analyse tree allometries. Further statistical investigations were performed using Bayesian piecewise regression (BPR) and Bayesian regression modelling (BRM). Basal area, number of stems, height, long canopy, diameter and basal circumference were all significantly different (p < 0.05) across all sampled plots. The change in growing conditions occurring as a tree grows beyond the reach of the African savannah elephant browsing indicates a natural system breakpoint. The best-fitting models were a simple linear model and a two breakpoint model for the plant population exposed to elephant herbivory. LULC, NDVI and SAVI confirm evidence of high tree regeneration over 2 decades. Understanding the dynamics in vegetation and LULC changes is critical for effective conservation and management of the habitats for African savannah elephants, as well as for maintaining the health and resilience of forest ecosystems.
Forest parks in megacities are pivotal in boosting biodiversity, purifying air, and offering essential green areas for community leisure and mental health amidst the hustle and bustle of cities. Yet, these vital oases encounter severe difficulties, including habitat degradation, contamination, and urbanization pressures, jeopardizing their preservation and the crucial ecological advantages they offer. The soil 's characteristics and its microbial inhabitants are fundamental in the cycling of nutrients and the well-being of plants, positioning them as central elements in restoration efforts. Nonetheless, the complex interplay among plant, soil, and microbial relationships during the restoration of forest ecosystems in megacities is still not well comprehended. This study aimed to investigate the interactions between plant-soil-microbial dynamics in different ecological restoration modes and construct assessment systems to evaluate the quality of restoration modes in the forest parks. The study identified a total of 25 distinct types of forests damaged by three main factors (farmland, highway, and quarrying) in Chongqing Taisiya Forest Park, and found that long-term natural restoration significantly increased soil properties in these forests. Additionally, an in-depth microbial sequencing analysis showed that Proteobacteria and Ascomycota were the major bacterial and fungal phyla dominant in the restoration process in the urban forests. Further correlation analysis showed that soil microbial diversity positively correlated with plant diversity, with a stronger correlation observed for bacterial communities compared to fungi. The comprehensive evaluation index results for the different forest types revealed varying degrees of restoration success. Collectively, our findings underscore the importance of forest attributes and soil microbial diversity in forest ecosystem restoration and provide valuable insights for designing effective restoration strategies in similar ecosystems.