Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Box 7024, SE, 750 07, Uppsala, Sweden; Institute of Resource Assessment, University of Dar Es Salaam, P.O. Box 35097, Dar Es Salaam, Tanzania.
Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Box 7024, SE, 750 07, Uppsala, Sweden.
J Environ Manage. 2021 Jul 15;290:112635. doi: 10.1016/j.jenvman.2021.112635. Epub 2021 Apr 19.
Miombo woodlands sustainability in east and south-central Africa is threatened by human activities, including overgrazing. This study investigated seasonal variations in rangeland condition in three grazed areas in miombo woodlands in eastern Tanzania. Transect lines were established across the grazing areas, sampling points were identified and marked at every 10% of the length of transect line. Sampling points were categorised in different distances with respect to settlement. The line intercept method was used to collect data on vegetation cover and forage distribution, while herbaceous forage biomass was estimated using a disc pasture meter. A total of 118 different plant species were observed and grasses comprised 40.6% of all herbaceous species. Bothriochloa pertusa, Cynodon plectostachyus, Hyparrhenia rufa and Urochloa mosambicensis grass species dominated miombo grazed areas in various seasons and distances. These perennial grass species are desirable and indicated moderate grazing activities in miombo. Season affected grass cover, herbaceous forage biomass and nutritional composition. Grass cover and forage biomass were at the lowest during late dry season while forage nutritional quality was best during early dry season. Distance from settlement had no effect on grass cover and herbaceous forage biomass. Rangeland condition was generally fair, livestock stocking rate in continuously grazed drylands should be set at the lowest monthly forage biomass in order to ensure grazing land sustainability.
东非和中非东南部的 miombo 林地的可持续性受到人类活动的威胁，包括过度放牧。本研究调查了坦桑尼亚东部 miombo 林地三个放牧区的牧场状况季节性变化。在放牧区设置了横断面线，在横断面线长度的每 10%处确定并标记采样点。采样点根据与定居点的距离分为不同的距离类别。采用线截距法收集植被覆盖和饲料分布数据，同时使用圆盘牧场计估计草本饲料生物量。共观察到 118 种不同的植物，其中草类占所有草本物种的 40.6%。在不同季节和距离下，Bothriochloa pertusa、Cynodon plectostachyus、Hyparrhenia rufa 和 Urochloa mosambicensis 等草类物种均为 miombo 放牧区的优势物种。这些多年生草类是理想的，表明 miombo 地区的放牧活动适度。季节影响草类覆盖率、草本饲料生物量和营养成分。在旱季后期，草类覆盖率和饲料生物量最低，而在旱季早期，饲料营养价值最高。与定居点的距离对草类覆盖率和草本饲料生物量没有影响。牧场状况总体良好，在连续放牧的干旱地区，牲畜存栏率应设定在每月最低的饲料生物量，以确保放牧土地的可持续性。
