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Mammalian herbivores restrict the altitudinal range limits of alpine plants
Author(s) -
Lynn Joshua S.,
Miller Tom E. X.,
Rudgers Jennifer A.
Publication year - 2021
Publication title -
ecology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.852
H-Index - 265
eISSN - 1461-0248
pISSN - 1461-023X
DOI - 10.1111/ele.13829
Subject(s) - herbivore , exclosure , range (aeronautics) , ecology , biology , habitat , population , biomass (ecology) , ecosystem , materials science , demography , sociology , composite material
Although rarely experimentally tested, biotic interactions have long been hypothesised to limit low‐elevation range boundaries of species. We tested the effects of herbivory on three alpine‐restricted plant species by transplanting plants below (novel), at the edge (limit), or in the centre (core) of their current elevational range and factorially fencing‐out above‐ and belowground mammals. Herbivore damage was greater in range limit and novel habitats than in range cores. Exclosures increased plant biomass and reproduction more in novel habitats than in range cores, suggesting demographic costs of novel interactions with herbivores. We then used demographic models to project population growth rates, which increased 5–20% more under herbivore exclosure at range limit and novel sites than in core habitats. Our results identify mammalian herbivores as key drivers of the low‐elevation range limits of alpine plants and indicate that upward encroachment of herbivores could trigger local extinctions by depressing plant population growth.