摘要:

SummaryBetween 1947 and 1967 tree frequency was reduced by 30% in the Narus valley, Kidepo Valley National Park. Between 1967 and 1972 a further 50% reduction took place on experimental plots. Elephants were largely responsible. Despite a regeneration potential ofc.200 young trees per ha, very little tree regeneration was observed. Experimental fire treatments and animal–free exclosures revealed that annual burning and the current browsing pressure were independently capable of preventing tree regeneration.Fire effects were significant in the herb composition of the animal exclosures but less so on the grazed areas. This was attributed to trampling of litter on the grazed areas, which assisted termites in litter removal. Untrampled litter accumulation suppressedThemeda triandrato the benefit ofPanicum maximum.Fire effects on the soil were small and impermanen

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1974.tb01028.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryThe purpose of the survey was to develop a meaningful method for assessing the utilization of the existing edaphic and serai grasslands in the park. Particular attention was given to the effect of grazing on the growth of different species of grasses, the course of plant succession and the fire hazard, in relation to the productivity and diversity of the environment. The distribution and composition of the different types of grassland are described and their suitability as pasture at different seasons is discussed.Utilization was assessed by recording the extent of short grass that is maintained by grazing in relation to the unused mature grass at different seasons of the year. Near optimum utilization of the edaphic (high water‐table) grasslands in the bottom lands takes place over a prolonged period. Utilization of the derived grasslands on the hills and uplands is increasing as the buffalo herds benefit by protection in the park. It is estimated that the available pastures can still accommodate an increased population of buffaloes and other grazing animals. Furthermore, advantages to the environment will accrue as a result of the reduced fire hazard.Buffaloes are the dominant grazing animals throughout and so mainly their impact on the vegetation is considered. The distribution and density of the buffalo population is recorded, and it is concluded that the existing number is well within the carrying capacity of the park. It is suggested that under‐grazing could be serious because of the increased fire risk that would result. In order to improve the grazing in the secondary grasslands preliminary trials for managing fire by patch burning have been successfully initia

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1974.tb01029.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SummaryAlthough it would appear that regulation in animal populations is highly probable, the evidence for it in nature is meagre. The various hypotheses on regulation are outlined in order to point out the critical evidence needed to test them. A population of the East African buffalo has been studied since 1965 with a view to obtaining this information.The ecological requirements including habitat selection and food selection are described. Using Association analysis the ‘best available’ habitat for buffalo was found to be a combination of riverine grassland and forest. This was most pronounced in the dry season when other habitats became less suitable due to the grass drying out and becoming unsuitable food. The movements between vegetation types were correlated with changes in rainfall and with the area of burnt ground after grass fires. Hence the movements could be attributed to changes in the food supply.Within the ‘best available’ habitats the buffalo ate grass exclusively but not all grass was food. The most preferred component was the combined grass leaf and leaf base, this being the most nutritious part of the plant. This component was predominant in the diet during the rains but declined to a minimum by the end of the dry season despite the animals' ability to select

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1974.tb01030.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1974.tb01031.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1974.tb01032.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1974.tb01033.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1974.tb01034.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1974.tb01035.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY