Two-Sex Demography, Sexual Niche Differentiation, and the Geographic Range Limits of Texas Bluegrass ( Poa arachnifera )
Two-Sex Demography, Sexual Niche Differentiation, and the Geographic Range Limits of Texas Bluegrass ( Poa arachnifera )
复制标题
两性人口统计学、性别生态位分化和德克萨斯早熟禾 (Poa arachnifera) 的地理范围限制
DOI：
10.1086/719668
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Compagnoni, Aldo
中科院分区：
文献类型：
--
作者：
Miller, Tom E.;Compagnoni, Aldo
Understanding the mechanisms that generate biogeographic range limits is a long-standing goal of ecology. It is widely hypothesized that distributional limits reflect the environmental niche, but this hypothesis is complicated by the potential for intraspecific niche heterogeneity. In dioecious species, sexual niche differentiation may cause divergence between the sexes in their limits of environmental suitability. We studied range boundary formation in Texas bluegrass (Poa arachnifera), a perennial dioecious plant, testing the alternative hypotheses that range limits reflect the niche limits of females only versus the combined contributions of females and males, including their interdependence via mating. Common garden experiments across a longitudinal aridity gradient revealed female-biased flowering approaching eastern range limits, suggesting that mate limitation may constrain the species’ distribution. However, a demographic model showed that declines in λ approaching range limits were driven almost entirely by female vital rates. The dominant role of females was attributable to seed viability being robust to sex ratio variation and to low sensitivity of λ to reproductive transitions. We suggest that female-dominant range limits may be common to long-lived species with polygamous mating systems and that female responses to environmental drivers may often be sufficient for predicting range shifts in response to environmental change.
