The Zambezi, Pungwe, Buzi, and Save rivers drain extensive areas of interior Southeast Africa. Rainfall in the region is highly seasonal, and the volume of water carried by these rivers varied with the wet and dry cycles of the year. The flooded savannas are found in low-lying coastal lowlands at the river mouths, on deposits of recent fluvisols deposited by the rivers.[2]
They Zambezian coastal flooded savannas cover an area of 19,346 km². The Zambezi flooded savannas cover the largest area, extending nearly 200 km along the Indian Ocean coast and extending up to 120 km inland. To the south are the adjoining floodplains of the Pungwe and Buzi, which create a flooded savanna of 4500 km². The smaller Save River flooded savannas lie further to the south. The East African mangroves lie between the flooded savannas and the coast in areas of brackish or salt water.[2]
Some large mammals migrate seasonally between the flooded savannas and the grasslands, forests, and woodlands of the neighboring uplands. Common eland (Taurotragus oryx) migrates to the seasonal wetlands at the start of the rainy season to browse on the young grasses. Populations of Lichtenstein’s hartebeest (Alcelaphus lichtensteinii) and sable antelope (Hippotragus niger) live in the flooded savannas during the dry season, and migrate to the uplands at the start of the rainy season.[2]
The construction of large dams on the Zambezi – Kariba Dam, completed in 1959, and Cahora Bassa Dam, completed in 1974 – altered the ecology of the Zambezi, reducing the annual wet-season flooding of the lower Zambezi and the overall volume of both water and sediment coming into the flooded savannas. Other threats include poaching and over-hunting. Wildlife was decimated during the Mozambican Civil War, and the African bush elephant (Loxodonta africana) and black rhinoceros (Diceros bicornis) were extirpated.[2]
Protected areas
A 2017 assessment found that 6,212 km², or 32%, of the ecoregion is in protected areas.[3] Protected areas include Marromeu National Reserve in the southwestern Zambezi delta, and the adjacent coutadas or hunting areas. Gorongosa National Park protects a portion of the northern Pungwe floodplain.
^Eric Dinerstein, David Olson, et al. (2017). An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 2017, Pages 534–545; Supplemental material 2 table S1b. [1]
^Eric Dinerstein, David Olson, et al. (2017). An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 2017, Pages 534–545; Supplemental material 2 table S1b. [2]