Livestock browsing affects the species composition and structure of cloud forest in the Dhofar Mountains of Oman

Abstract

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Anthropogenic Pressure on Tree Species Diversity, Composition, and Growth of Balanites aegyptiaca in Dinder Biosphere Reserve, Sudan

“…During the wet season, livestock utilize and depend on perennial and herbaceous plants that are generally available in and around the villages [41,47,73]. A healthy population structure is usually characterized by higher seedling and sapling (young generation) proportions compared to mature trees [2,19,60]. Our results of higher seedling and sapling densities in the non-disturbed sites agree with these conclusions.…”

“…Intensive browsing by livestock influences the recruitment of the tree seedlings and saplings and disturbs the population dynamics [ 2 , 19 , 65 ]. The density of seedlings of Quercus ithaburensis Decne and Quercus agrifolia Ne’e in Israel and north California, respectively, declined to <50% of the initial population due to intensive browsing and overgrazing of livestock [ 66 , 67 ] and a 50% tree species decline was observed in the Galician oak forest of Northwest Spain [ 68 ].…”

“…Other factors that might cause a fluctuation in natural regeneration are the type of browsers that dominate the site [ 21 , 77 ]. Goats are characterized by an extensive browsing habit with the preference for woody plants and broadleaved tree species [ 77 , 78 , 79 ], while cattle and camels prefer grazing on herbaceous plants and browsing the crown of mature trees, respectively [ 19 , 21 , 80 ]. Although grasses might protect small tree seedlings from browsing livestock [ 81 , 82 ], in the DBR, only little grass cover remained during the dry season, and grasses were severely overgrazed by livestock [ 14 , 73 , 83 ].…”

“…While browsing likely affects the seedlings and saplings of highly palatable tree species [ 19 , 20 , 21 ], the human impact focuses on mature tree resources such as stem bark for medicine [ 22 , 23 ], stem and branches for timber [ 24 , 25 ] or firewood production [ 26 , 27 , 28 , 29 ]. Despite an ongoing high human and livestock pressure, information regarding the health status of the common tree species in the Dinder Biosphere Reserve is limited.…”

“…Livestock grazing and browsing affect the natural regeneration of trees and reduce the species diversity in frequently grazed/browsed areas [ 19 , 40 , 41 ]. Results on diversity responses to disturbance are indefinite; diversity indices are often lower in disturbed systems, as only limited tree species survive intensive browsing and illegal felling [ 24 , 42 ].…”