高原鼢鼠鼠丘不同演替阶段植物功能群的特征及其影响因素

Plant functional group characteristics in different successional stages of plateau zokor mounds and influencing factors

中文关键词:高原鼢鼠  植物功能群  演替  繁殖方式  生活型  根系类型

keywords:plateau zokor  plant functional group  succession  reproductive mode  life form  root type

中文摘要:为明确高寒草甸高原鼢鼠Eospalax baileyi鼠丘不同演替阶段植物功能群的特征及其影响因素，选取不同年限鼠丘及无鼠丘草地对植物的繁殖方式、生活型和根系类型进行调查，采用冗余分析法探究鼠丘植物功能群（繁殖功能群、生活型功能群和根系功能群）物种数、多度和地上生物量特征及其与土壤环境因子的关系。结果表明：无鼠丘草地植物繁殖方式以种子繁殖兼具无性繁殖的功能群占优势，其多度相对百分比为58.4%，地上生物量相对百分比为64.8%，鼠丘上植物以种子繁殖功能群为主，在3年生鼠丘上占比最高，多度相对百分比和地上生物量相对百分比分别为76.4%和75.5%；无鼠丘草地植物的生活型以地面芽和地下芽功能群为主，其多度相对百分比分别是52.4%和39.8%，地上生物量相对百分比分别是47.3%和48.5%，而鼠丘上植物中地面芽功能群减少，地上芽功能群增多，2年生鼠丘上植物以地下芽功能群占优势，其多度相对百分比和地上生物量相对百分比分别为68.0%和73.6%；无鼠丘草地植物以根茎型和须根型功能群为主，其多度相对百分比达到57.7%和28.0%，地上生物量相对百分比达到56.9%和25.7%，1年生和2年生鼠丘上植物以轴根型和根茎型功能群为主，3年生鼠丘上植物以块根型、轴根型、须根型和根茎型功能群为主，3年以上鼠丘上植物以块根型、须根型和根茎型功能群为主。冗余分析结果表明高原鼢鼠干扰主要通过改变土壤水分、土壤氮磷养分等资源条件来影响鼠丘植物功能群特征。

Abstract:To clarify the characteristics of plant functional groups and the influencing factors at different successional stages of plateau zokor mounds in alpine meadows, a survey of plant reproductive modes, life forms, and root types in mounds of different ages and adjacent non-mounded grassland was conducted. The redundancy analysis was employed to explore the relationship among the species richness, abundance, and biomass characteristics of plant functional groups (reproductive functional groups, life form functional groups, and root functional groups) and soil environmental factors. The results indicated that the plants in non-mounded grassland were predominantly reproducing via seeds with some employing vegetative reproduction, with relative abundance percentage of 58.4% and relative aboveground biomass percentage of 64.8%. In contrast, plants on zokor mounds primarily relied on seed reproduction functional groups, with the highest proportions on three-year-old mounds, where their relative abundance and aboveground biomass percentages were 76.4% and 75.5%, respectively. Life forms in non-mounded grassland were mainly ground bud and underground bud functional groups, with relative abundance percentages of 52.4% and 39.8% and relative aboveground biomass percentages of 47.3% and 48.5%, respectively. Whereas plants on zokor mounds, the ground bud functional group decreased while the aboveground bud functional group increased. On two-year-old mounds, underground bud plants were dominant, with relative abundance and relative aboveground biomass percentages of 68.0% and 73.6%, respectively. Plant roots in non-mounded grassland were mainly rhizome and fibrous root type functional groups, with relative abundance percentages reaching 57.7% and 28.0%, and relative aboveground biomass percentages of 56.9% and 25.7%, respectively. On one-year and two-year-old zokor mounds, the dominant plants were primarily axial root and rhizome functional groups. For three-yearold mounds, the plants consist mainly of tuberous, axial root, fibrous root, and rhizome functional groups, while plants on mounds older than three years were primarily dominated by tuberous, fibrous root, and rhizome functional groups. Redundancy analysis results indicated that plateau zokor disturbance primarily influenced the characteristics of plant functional groups in mounds by altering soil moisture and nitrogen and phosphorus nutrient availability.