Mammalian herbivores restrict the altitudinal range limits of three alpine grass species (transplant and herbivore exclusion experiment and demographic data from natural populations), West Elk Mountains, Colorado, USA 2015-2018

• Main Authors: Joshua S. Lynn, Jennifer A. Rudgers, Tom E.X. Miller
• Format: Dataset
• Language: unknown
• Published: Environmental Data Initiative 2021
• Subjects: Herbivory; biotic interactions; MPM/IPM demographic modeling; population ecology; Dobzhansky-MacArthur hypothesis; experiment; biogeography; climate change; plants; Elymus Elymus scribneri; Festuca Festuca brachyphylla; Poa Poa alpina; Elymus scribneri; Festuca brachyphylla; Poa alpina; Avery
• Online Access: https://pasta.lternet.edu/package/metadata/eml/edi/839/2

Though rarely experimentally tested, biotic interactions have long been hypothesized 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 center (core) of their current elevational range and factorially fencing-out above- and belowground mammals in the West Elk Mountains, Colorado, USA from 2015-2018. 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.