I need help with what to add to what I have so far because it needs to be 3/4s o
ID: 161859 • Letter: I
Question
I need help with what to add to what I have so far because it needs to be 3/4s of a page. Here is the oraginal questinon. Needs to be about african savannas
The state of a savanna ecosystem, at any given moment, is shaped by a number of forces acting upon it. Theoretically, in a pristine savanna, these forces would be in balance, over a sufficiently long time horizon. Discuss the interactions of:
-trees / grass / fire, and
-browsers / grazers / elephants
in shaping the savanna ecosystem.
heres what I have so far.
The effects of fire/grazing/grazers/elephants interactions on grasslands are extremely complex. Grasses compete with wooded plants for water in the topsoil and elimination by grazing reduces this competitive effect, possibly boosting tree growth. Persistent substantial grazing can prevent the spread of fire by breaking up the grass layer. In contrast, frequent burning might inhibit the persistence of grazed patches by attracting grazers to the post-burn green flush. Elephants engage in tactics such as bark stripping, breaking major branches, and uprooting trees and shrubs when browsing.
Explanation / Answer
The African savanna ecosystem is characterized by the existence of both woody trees and grasses in the same ecosystem.This tree—grass coexistence is of high importance for conservation. But, there are major concerns in these areas as higher levels of elephant densities could lead to repression of biodiversity, which would lead to
reduction oflevels of specific woody trees and a decreased overall patch density signaling an increase in homogeneity of ecosystems. The major forces acting upon this coexistence are elephant herbivory, water, nutrients, and stochastic environmental variables such as fire and rainfall.The African elephant is a major environmental force in this ecosystem because of its behavior, including nutrient cycling, dispersal of plant offspring in seeds, and allowing for new plants to germinate in adequate space. An important behavior that characterizes these populations is that during the summer when weather is dry, the elephant prefers to graze, or feed on grasses, whereas this behavior seemingly switches during the Wet season, when the elephant turns to browsing leaves off of taller, woody trees.This browsing during the wet season has had a significant effect on woody trees, in that the habitat modification resulting from browsing has been ascribed to loss of canopy trees and an eventual transition to bushland dominated by shorter grasses and shrubs. Thus, high elephant densities could irreversibly alter the structure and physiology of African savanna ecosystems .
Savannas are ecosystems comprising of a mixture of woody species (trees and bushes), grasses and forbs. A savanna, where trees and grasses coexist , may be viewed as an intermediate ecosystem between grassland (grass dominance) and forest (tree dominance) with increasing precipitation resulting in a denser tree layer yet still discontinues in comparison to a forest . Fire is an indissoluble component of savanna ecosystems Savannas are mainly characterised by ground fires as fuel load derives mainly from grass biomass and such fires occur mainly in mesic or humid savannas .