草本和灌木的养分含量及其与海南坡鹿食性的关系

Nutrient content of herbage and shrub forage and its relationship to the eating habits of Cervus eldi hainanus

在海南大田国家级自然保护区围栏内采集海南坡鹿经常采食的草本植物和灌木各18种,测定其水分(Water)、粗蛋白质(CP)、粗纤维(CF)、无氮浸出物(NFE)、钙(Ca)、铁(Fe)、锰(Mn)、锌(Zn)和铜(Cu)含量。结果表明,草本植物的水分和粗纤维含量显著高于灌木,粗蛋白质、钙和微量元素含量显著低于灌木,二者的无氮浸出物含量无显著差异。研究认为,草本植物含水量较高,采食时感觉幼嫩可口,是海南坡鹿对其喜食的重要原因之一;植物的粗纤维含量是导致海南坡鹿喜食幼嫩植物或植物幼嫩部位的关键原因,坡鹿对粗纤维含量超过25%的植物部位不喜食;在面积相对有限、旱季长达半年的海南大田自然保护区围栏内,草本植物是坡鹿的主要能量来源,灌木是坡鹿维持生态营养平衡供给的重要补充。

The nutrient content of herbage and shrub forage often grazed by Cervus eldi hainanus was determined, and correlated eating habits of Cervus eldi analyzed. Forage samples of 36 species (18 herbage and 18 shrub species) were collected from within the fenced off area of the Hainan Datian National Nature Reserve. The content of water, crude protein (CP), crude fiber (CF), nitrogen-free extract (NFE), calcium (Ca), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) of each sample was determined. The results showed that herbage contained higher contents of CF and water than shrubs, but lower contents of CP, Ca and microelements. There was no significant difference in NFE content between the two forage types. A factor considered important in leading to Cervus eldi favoring herbage forage was its higher water content, and young, tender and palatable feeling when being eaten. CF content is the key factor leading to Cervus eldi preferring to eat young and tender plants or the young and tender parts of plants. Cervus eldi were not fond of grazing plant parts with more than 25% CF. In the relatively restricted area with long half-year dry seasons within the fenced off area, herbage, with high NFE content, is the main source of energy for Cervus eldi, but shrubs, containing higher contents of CP, Ca and microelements, provide an important supplement for maintaining ecological nutritional balance.