Andean Grassland Species: Net Aerial Primary Productivity, Density, Ecomorphological Indices, and Soil Characteristics

Abstract

The tall grass vegetation in the Andean grassland ecosystems covers the largest area compared to other types of vegetation such as Puna grass, wetland and others. The grasslands are frequently set on fire by livestock farmer, seriously affecting the ecosystem. One way to mitigate this problem is to use these species as a source of plant fibre, which can be economically useful to the interests of the livestock family without affecting the ecosystem. To advance in this approach, it is necessary to know the functional characteristics of the plants; therefore, we evaluated the aerial primary productivity, plant density per m 2 , basal cover, aerial cover and leaf height, whose data were analysed using the generalised linear mixed model and the correlation between these variables with the physical-chemical characteristics of the soil, by means of principal component analysis and canonical correlation, in seven species of grassland and seven control plots, located between 3860 and 4333 metres above sea level. The results showed significant differences for p=0.001 between species, and between plots, and a canonical correlation grouped in two clusters that showed the differentiated importance of soil elements with the phytomass produced

Aerial Phytomass Production and Growth Performances of Five Common Tall Species in Andean Grasslands at Harvesting and Application of Natural Fertilizers

“…However, the difference in aerial net primary production observed between plots was due to the particular characteristics of each species that were dominant in each particular case such as: the length and width of the leaves, height, and thickness of the stems, the number of bushes, in addition to the soil characteristics [15], in this understanding the first three plots in the production of dry matter, is based on: a) the species C. intermedia and C. antoniana are plants with greater tillering with more solid and thicker leaves and stems that were present in P1, P2, and P3, as opposed to the species C. tarmensis, which is characterized by a morphology contrary to that mentioned by Tovar [33] and was present in plot P4, b) plots P4 and P5 are located on shallower soils with a light brown color, which is indicative of soils with a lower concentration of carbon, organic matter, and nitrogen, due to their higher concentration of silt and clay particles containing Fe oxides [35]. This corroborates that soil characteristics determine not only plant cover but also plant productive capacity [28,29].…”

“…"The morphological indicators of some improved forage grasses have often been measured to evaluate the forage quality and phenological evolution of certain ecotypes adapted to specific environmental conditions using various morphological descriptors, mainly related to the characteristics of leaves and stems, as well as their dry matter production capacity and nutritional quality for livestock" [19,20]; However, these measurements have not yet been extensively developed on native species such as high Andean grasslands, as the scarce information available is oriented towards the forage value of those species that are highly desirable for livestock, such as the study carried out in Uruguay [21,22], with the exception of net aerial primary productivity, which was studied by Yaranga et al [15]. This situation does not allow us to make objective comparisons with the results of this research.…”

“…"The difference in canopy height between species is based on the morphological nature of the species, as C. antoniana and C. intermedia are very tough and leathery species, with more solid canes" [33], while the others have thin leaves and thinner canes [32,15].…”

“…Experience similar to the case study in Peru is very scarce, but some studies related to the phenology of some species have been carried out, while other studies in Uruguay worked on N and P fertilization [13]. The net aerial primary production of these species in natural conditions was reported by Yaranga et al [15] for Calamagrostis intermedia 383±18.6 grams of dry matter per plant (g DM/plant), for C. antoniana 313±17.6 g DM/plant, Festuca rigidifolia 216±23.1 g DM/plant, Festuca sp 182±24.3 g DM/plant, and C. tarmensis 104±21.6 g DM/plant. In this context, the objective was to evaluate the aerial cover, canopy height, and aerial phytomass production of five common tall species in the area: Calamagrostis intermedia (paja chamik), C. antoniana (hatún pork'e), C. tarmensis (pork'e), Festuca rigidifolia (chilligua cachi), F. sp (chilligua), on plots fertilized with cattle manure and rock phosphate, during a 9month control period.…”

Organic Carbon Stored in the Aerial Phytomass of Fire-threatened Andean Grassland Species

“…The Andes Mountains of Peru and Latin America, are covered by natural grasslands that mostly consist of tussock grasslands, a type of vegetation dominated by tall matted species with higher lignin and cellulose content, which are scarcely or not at all consumed by livestock; however, these ecosystems are major providers of ecosystem services such as water regulation, CO₂ sequestration, and organic carbon storage, soil protection against erosion, filtration of surface runoff [1][2][3], protection of vulnerable grassland species from where they provide seed for dissemination, shelter, and feeding of wildlife, among others [4]. These ecosystems are being threatened by anthropogenic action [5], through frequent fires caused by local ranchers, with the idea of causing the temporary growth of tender shoots useful for animal feed.…”