Botanical characterization of the dominant grassland in the ecuadorian subtropic: comparative study between two altitudinal floors

Abstract

In order to botanically characterize the dominant grassland in the Ecuadorian subtropics in two altitudinal levels, using a mobile quadrant of 1x104 cm2, the botanical composition was established considering the types of grass vegetation (grass), legumes and unwanted plants (broadleaf and narrow), in addition, the biomass by type of vegetation was established. The study was carried out between the end of the dry season (October - November) and the beginning of the rainy season (December - January). From highest to lowest relative frequency, the botanical composition in both altitudinal levels was grasses, legumes, and unwanted broad- and narrow-leaved plants, with the proportion of grasses, legumes, and unwanted plants at 500 meters above sea level being 74.02, 18.56, and 7.42%. , respectively, and at 1000 meters above sea level of 82.77, 12.59 and 4.64%. It was also observed that the number of plant species increases from 9 to 12, when the altitudinal floor changes from 500 to 1000 meters above sea level. The availability of fresh biomass was greater at 1000 meters above sea level with 2039 g/m² compared to the availability of fresh biomass at 500 meters above sea level with 1450 g/m², and the same trend was observed when evaluating dry biomass with values of 727 and 569 g/m². m², respectively. Differences in botanical composition and biomass availability between the two altitudinal levels are highlighted. At higher altitudes, greater plant diversity and a greater amount of biomass are observed, underscoring the crucial influence of altitude on the structure and function of these ecosystems. The botanical composition is partially different in both altitudinal levels, where the species Brachiaria decumbens, Setaria sphacelata and Arachis pintoi are common in both levels, while Stenotaphrum secundatum is present at lower altitudes and Megathyrsus maximus at higher altitudes. The pressure from unwanted plants intensifies at lower altitudes, due to an increase in unwanted narrow-leaved plants.