title: Brown world forests: increased ungulate browsing keeps temperate trees in recruitment bottlenecks in resource hotspots.
abstract: Plant biomass consumers (mammalian herbivory and fire) are increasingly seen as major drivers of ecosystem structure and function but the prevailing paradigm in temperate forest ecology is still that their dynamics are mainly bottom-up resource-controlled. Using conceptual advances from savanna ecology, particularly the demographic bottleneck model, we present a novel view on temperate forest dynamics that integrates consumer and resource control. We used a fully factorial experiment, with varying levels of ungulate herbivory and resource (light) availability, to investigate how these factors shape recruitment of five temperate tree species. We ran simulations to project how inter- and intraspecific differences in height increment under the different experimental scenarios influence long-term recruitment of tree species. Strong herbivore-driven demographic bottlenecks occurred in our temperate forest system, and bottlenecks were as strong under resource-rich as under resource-poor conditions. Increased browsing by herbivores in resource-rich patches strongly counteracted the increased escape strength of saplings in these patches. This finding is a crucial extension of the demographic bottleneck model which assumes that increased resource availability allows plants to more easily escape consumer-driven bottlenecks. Our study demonstrates that a more dynamic understanding of consumer-resource interactions is necessary, where consumers and plants both respond to resource availability.
authors.affiliation: Mammal Research Institute, Polish Academy of Sciences, Waszkiewicza 1, 17-230, Białowieża, Poland.
authors.forename: Marcin
authors.identifier: http://orcid.org/0000-0001-8727-0203
authors.initials: M
authors.lastname: Churski
authors.affiliation: Mammal Research Institute, Polish Academy of Sciences, Waszkiewicza 1, 17-230, Białowieża, Poland.
authors.forename: Jakub W
authors.initials: JW
authors.lastname: Bubnicki
authors.affiliation: Mammal Research Institute, Polish Academy of Sciences, Waszkiewicza 1, 17-230, Białowieża, Poland.
authors.forename: Bogumiła
authors.initials: B
authors.lastname: Jędrzejewska
authors.affiliation: Mammal Research Institute, Polish Academy of Sciences, Waszkiewicza 1, 17-230, Białowieża, Poland.
authors.forename: Dries P J
authors.initials: DP
authors.lastname: Kuijper
authors.affiliation: Department of Wildlife, Fish and Environmental Studies, SLU, 901 83, Umeå, Sweden.|Centre for African Conservation Ecology, Department of Zoology, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031, South Africa.
authors.forename: Joris P G M
authors.initials: JP
authors.lastname: Cromsigt
mesh_terms: D000818:Animals; D003198:Computer Simulation; D065928:Forests; D005843:Geography; D060434:Herbivory / Q000502:physiology*; D008322:Mammals / Q000502:physiology*; D008962:Models, Theoretical; D011044:Poland; D013045:Species Specificity; D014197:Trees / Q000502:physiology*
keywords: Białowieża Forest; consumer control; demographic bottleneck model (DBM); green vs brown world species; savanna vs forest ecology