草原退化过程中植物功能群数量特征的变化

本研究以内蒙古高原东部克鲁伦河流域的放牧退化草原作为研究对象，在植物功能群划分的基础上，比较不同类别功能群在放牧梯度上的垂直分异和地上生物量的空间分布。结果显示：在中度放牧条件下，水分生态型功能群和种子传播类型功能群的植物生长较好；在轻牧区，生活型功能群的物种高度最大；生育型功能群中，匍匐型植物随着放牧强度的增加而减少。地上生物量的分布而言，植物水分生态型功能群中，旱生植物在中度和轻度放牧区占有绝对优势地位，强旱生植物在强度放牧区优势明显；植物生活型功能群中，多年生草本植物在不同放牧强度下都占有明显优势；生育型功能群中，丛生型植物在中度和轻度放牧区分布较广，重度放牧区中鳞茎植物占优势；从种子传播类型功能群来看，重力传播方式的植物在重度放牧区占绝对优势主。在中度放牧条件下草原群落的物种多样性最高。

Study on Quantitative Characteristics of Plant Functional Groups During Degradation Process of Grassland

In this paper, taking the grazing degradation grassland in Kherlon River Basin which is in the East Mongolia Plateau as research object, we focus on comparing the vertical differenti- ation of grazing gradients of different plant functional groups and spatial distribution of the bio- mass based on the division of plant functional groups. The results show that under moderate grazing conditions, most plants of moisture ecological functional groups and seed propagation type functional group grow better; Species growing height of life functional groups is biggest un- der slight grazing conditions; In growth functional groups, creeping plants is decreasing with the grazing levels increasing. From the distribution of aboveground biomass perspective, in moisture ecological functional groups, xerophytes occupy a dominant position in moderate and mild graz- ing areas, but strong xerophytes have obvious advantages in the severe grazing areas; In the life -form functional group, perennial herbs have a significant advantage in different intensity graz- ing areas; In growth functional groups, clumping plants mainly distribute in moderate and mild grazing areas and bulbs plants mainly in severe grazing areas. In the light of seed propagation type functional groups, strong propagation type plants mainly live in severe grazing areas. Mean- while, all kinds of species prefer living in the moderate grazing areas.