Ecological Distribution Patterns of Wild Grasses and Abiotic Factors

Abstract

Documentation the relative influence of ecological dynamics on species diversity patterns can help us better understand spatial distribution patterns and devise a systematically comprehensive base for carrying out environmental explorations. The current attempt aimed at exploring the distribution patterns, diversity and richness of wild grasses with respect to climatic dynamics in the Gujrat district of Punjab, Pakistan. For this purpose, we applied the randomized sample method and sampled a total of 90 sites across the Gujrat district between 2019 and 2021 to document data on wild grasses and related ecological conditions. After assessment of the significant value index of each grass species with ecological records, we evaluated the data by ordination and cluster analysis. A total of 57 wild grasses from 37 genera were documented from the Gujrat district. The leading genera were Brachiaria, Cenchrus and Setaria, each accounting for 7.02% of all documented species, followed by Aristida and Panicum, each representing 5.76% of the species. Dactyloctenium, Dichanthium, Eragrostis, Polypogon, Poa and Saccharum each accounted for 5.26% of the species, and Digitaria, Pennisetum, Eragrostis, Chrysopogon Poa and Setaria each accounted for 3.51% of the species. Other genera each had a single species. Among all grasses, 75.44% of the species were native and 24.56% species were exotic and introduced to the study area. The leading life forms were therophytes (56.14%), followed by hemicryptophytes (42.11%) and geophytes (1.75%). Microphylls, with a 54.39% share, dominated the leaf size spectra of the wild grasses flora in this research. Other frequent classes included nanophylls (21.05%), macrophylls (19.3%) and leptophylls (5.26%). Flowering phenology of wild grasses showed that mainly species at the flowering phase were recorded during the months of June to August (40.35%) and July to September (19.29%). By applying Ward’s agglomerative clustering method, we classified the ninety transects into four major groups. Ordination analysis showed that different ecological factors had significant (p ≤ 0.002) effects on vegetation relations. The present endeavor provides a basic way to understand the impacts of ecological variables on the structure, diversity, composition and associations of wild grasses, which are helpful to improve the scientific-informed conservation and management measures for the environmental reestablishment of degraded habitat in the studied region.