Korn Horst, Korn Ursula
Fachbereich Biologie-Zoologie, Philipps-Universität, D-3550, Marburg, Federal Republic of Germany.
Oecologia. 1989 May;79(2):271-278. doi: 10.1007/BF00388488.
Due to burrowing activity and selective feeding, the highveld gerbil, Tatera brantsii A. Smith, has a great influnce on grassland vegetation. Within old colonies, in comparison to control sites, total biomass of plants was reduced by 47.6% from an average of 234.0 g/m to 122.6 g/m. Root biomass was reduced by 34% from 539 g/m to 355 g/m. Correspondingly maximum vegetation heights decreased by 33.5% from 106.4 cm to 70.8 cm. The number of plant species was not different between disturbed and undisturbed sites but species diversity and evenness of plants were significantly increased in gerbil colonies, mainly due to the reduction in dominant grass species. In disturbed sites dicotyledone plants, especially legumes, were favoured and increased in biomass. The gerbils are considered an integral part of the system and necessary for the maintepance of a high species diversity of plants. The regular "disturbance" of savanna vegetation followed by the "recovery" of the system is driven by the movement of gerbil colonies across the area. The proposed mechanism and the alternating vegetation pattern on similar soils due to disturbances which are an integral part of the system is in agreement with Remmert's mosaic cycle theory.
由于挖掘活动和选择性觅食，高地沙鼠（Tatera brantsii A. Smith）对草原植被有很大影响。在旧栖息地内，与对照地点相比，植物总生物量从平均234.0克/平方米减少到122.6克/平方米，减少了47.6%。根生物量从539克/平方米减少到355克/平方米，减少了34%。相应地，最大植被高度从106.4厘米下降到70.8厘米，下降了33.5%。受干扰和未受干扰地点的植物物种数量没有差异，但沙鼠栖息地内植物的物种多样性和均匀度显著增加，主要是由于优势草种减少。在受干扰地点，双子叶植物，尤其是豆科植物，受到青睐，生物量增加。沙鼠被认为是该系统不可或缺的一部分，对于维持植物的高物种多样性是必要的。稀树草原植被的定期“干扰”随后是系统的“恢复”，这是由沙鼠栖息地在该地区的移动驱动的。所提出的机制以及由于干扰导致的类似土壤上交替出现的植被模式是该系统不可或缺的一部分，这与雷默特的镶嵌循环理论一致。
