Department of Forest Resources & Wildlife Management, National University of Science & Technology, Ascot, Bulawayo, Zimbabwe.
Debshan Ranch, Shangani, Zimbabwe.
PLoS One. 2022 Apr 28;17(4):e0248795. doi: 10.1371/journal.pone.0248795. eCollection 2022.
In east and southern Africa some private ranch owners are corralling (hereafter kraaling) cattle overnight for short periods (for example, seven days) in natural rangelands to create nutrient enriched hotspots which are attractive to large herbivores. However, the effect of season and time after kraal use (alt. age of nutrient enriched hotspots) on large herbivore use of these sites has not been examined. We collated the number of large herbivore sightings per day from camera traps during wet, early and late dry season in nutrient enriched hotspots of varying ages (1, 2, 3 and 4 years) and surrounding vegetation. In addition, above ground grass biomass and height in nutrient enriched hotspots was compared to that of the surrounding vegetation. Furthermore, we tested if repeated grazing in nutrient enriched hotspots stimulated grass compensatory growth. Large herbivore use of nutrient enriched hotspots was similar during wet, early and late dry season. Time after kraal use had a significant effect on mixed feeders (impala and African savanna elephant) utilization of nutrient enriched hotspots but not grazers (zebra and warthog) and browsers (giraffe and greater kudu). Both impala and African savanna elephants mostly used nutrient enriched hotspots one year after kraal use. Aboveground grass biomass and height were higher in surrounding vegetation than in nutrient enriched hotspots. Repeated clipping (proxy for grazing) resulted in compensatory aboveground grass biomass in nutrient enriched hotspots, which declined with time after kraal use. We concluded that nutrient enriched hotspots created through short duration overnight kraaling were important foraging sites for large herbivores.
在东非和南非,一些私人牧场主在天然牧场中将牛群围起来过夜(以下简称围圈),时间很短(例如 7 天),以创造富含营养的热点,吸引大型食草动物。然而,季节和围圈使用后时间(替代营养丰富热点的年龄)对这些地点大型食草动物使用的影响尚未得到检验。我们整理了在营养丰富的热点(年龄为 1、2、3 和 4 年)和周围植被中,不同时期(湿季、早干季和晚干季),相机陷阱每天拍摄的大型食草动物的目击数量。此外,还比较了营养丰富的热点和周围植被中的地上草生物量和高度。此外,我们还测试了营养丰富的热点中反复放牧是否刺激了草的补偿性生长。在湿季、早干季和晚干季,营养丰富的热点对大型食草动物的利用情况相似。围圈使用后的时间对混合食草动物(黑斑羚和非洲草原象)利用营养丰富的热点有显著影响,但对食草动物(斑马和疣猪)和食叶动物(长颈鹿和大角斑羚)没有影响。黑斑羚和非洲草原象大多在围圈使用一年后利用营养丰富的热点。地上草生物量和高度在周围植被中高于营养丰富的热点。重复修剪(放牧的代理)导致营养丰富的热点中地上草生物量补偿性增加,但随着围圈使用后时间的延长而下降。我们的结论是,通过短期夜间围圈产生的富含营养的热点是大型食草动物重要的觅食地点。