首页分享荒漠草原不同土壤生境猪毛蒿个体大小依赖的繁殖分配

荒漠草原不同土壤生境猪毛蒿个体大小依赖的繁殖分配

来源：花匠小妙招时间：2024-12-21 04:29

摘要： 植物繁殖分配是生活史理论的核心问题,一直受到生态学家们的关注。为了研究荒漠草原异质生境下植物的繁殖分配策略,本研究以生长在风沙土、灰钙土和基岩风化残积土生境下的猪毛蒿为研究对象,调查了不同个体大小的猪毛蒿生物量特征,分析了生物量间的相关关系和位置效应,讨论了繁殖器官的绝对投入量及其繁殖分配特点。结果表明:基岩风化残积土生境下猪毛蒿的地上生物量和地下生物量、营养器官生物量和生殖器官生物量、繁殖体数量和繁殖体重量等均小于风沙土和灰钙土生境。单株猪毛蒿上、中、下部的地上生物量、繁殖体数量、繁殖体重量和单个头状花序重量均未表现出资源投入的差异性(P>0.05)。繁殖器官生物量的绝对投入(lg R)随着个体大小(lg V)的增大而增加,表现出极显著正相关关系(P<0.001),说明猪毛蒿对营养生长和繁殖的资源投入是同时增加的。基岩风化残积土、风沙土和灰钙土生境下猪毛蒿的繁殖阈值分别为2.07、1.96和1.99 g,其繁殖分配和个体大小均呈现出负相关关系(P<0.05)。不同土壤生境下猪毛蒿单个头状花序重量和个体大小、每株头状花序数量间均呈负相关关系,这种差异性一定程度上反映了种群资源配置的表型可塑性,但这些权衡间没有显著的相关关系(P>0.05)。

关键词: 荒漠草原, 异质生境, 猪毛蒿, 个体大小, 繁殖分配

Abstract: The reproductive allocation of plants is an important factor in the theory of life history. The distribution of heterogeneous habitats is an important environmental factor affecting plant species on the desert steppe. To study the reproductive allocation strategies of plants on the desert steppe, we selected Artemisia scoparia growing in heterogeneous habitats (aeolian sandy soil, sierozem soil, and weathering bedrock) and evaluated the biomass characteristics of individuals of different sizes. We analyzed the relationships between biomass and biomass position, and evaluated the absolute inputs to reproductive organs and the characteristics of reproductive allocation. The results showed that aboveground biomass, underground biomass, reproductive organ biomass, vegetative organ biomass, number of reproductive bodies, and weight of reproductive bodies of A. scoparia were lower in plants growing on weathering bedrock than in plants growing in aeolian sandy soil and sierozem soil. There were no significant differences in aboveground biomass, number of reproductive bodies, weight of reproductive bodies, and single capitulum mass among different parts of single plant (P>0.05), suggesting that there was no difference in observed resource input in A. scoparia. The absolute input to reproductive organ biomass (lg R) increased as the size of the individual plant (lg V) increased (P<0.001), indicating that vegetative growth and resource input to reproduction in A. scoparia increased simultaneously. The reproductive thresholds of A. scoparia growing on weathering bedrock, aeolian sandy soil, and sierozem soil were 2.07, 1.96, and 1.99 g, respectively, and there was a negative correlation between reproductive allocation and individual size in the different habitats (P<0.05). There were negative correlations between single capitulum mass and individual size, and between single capitulum mass and the number of capitula on each plant. These differences reflected phenotypic plasticity in the resource allocation of A. scoparia, but there were no significant correlations between these trade?offs (P>0.05).

Key words: desert steppe, different habitats, Artemisia scoparia, individual size, reproductive allocation