Comparative response of Rangifer tarandus and other northern ungulates to climatic variability

Robert B Weladji,Atle Mysterud,David R Klein,Øystein Holand

doi:10.7557/2.22.1.686

Robert B Weladji, Atle Mysterud + Show 2 more

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https://doi.org/10.7557/2.22.1.686

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Journal: Rangifer	Publication Date: Jun 1, 2002
Citations: 102	License type: CC BY 3.0

Affiliation: University of Oslo, University of Alaska Fairbanks

Abstract

To understand the factors influencing life history traits and population dynamics, attention is increasingly being given to the importance of environmental stochasticity. In this paper, we review and discuss aspects of current knowledge concerning the effect of climatic variation (local and global) on population parameters of northern ungu&not;lates, with special emphasis on reindeer/caribou (Rangifer tarandus). We also restrict ourselves to indirect effects of climate through both forage availability and quality, and insect activity. Various authors have used different weather variables; with sometime opposite trends in resulting life history traits of ungulates, and few studies show consistent effects to the same climatic variables. There is thus little consensus about which weather variables play the most sig&not;nificant role influencing ungulate population parameters. This may be because the effects of weather on ungulate pop&not;ulation dynamics and life history traits are scale dependent and it is difficult to isolate climatic effects from density dependent factors. This confirms the complexity of the relationship between environment and ecosystem. We point out limits of comparability between systems and the difficulty of generalizing about the effect of climate change broadly across northern systems, across species and even within species. Furthermore, insect harassment appears to be a key climate-related factor for the ecology of reindeer/caribou that has been overlooked in the literature of climatic effects on large herbivores. In light of this, there is a need for further studies of long time series in assessing effects of climate variability on reindeer/caribou.

Highlights

Determining the causes of spatio-temporal variation in life history traits among individuals is one of the main goals of ecology (Begon et al, 1996)
We discuss the inditory traits and population dynamics of northern rect effect of climate through insect harassment on ungulates, attention is increasingly being given to reindeer/caribou, an aspect that has been largely the importance of environmental stochasticity overlooked by reviews in this field
We review and dis¬ in forage quality is strongly influenced by weather cuss central aspects of the current knowledge con¬ (B0 & Hjeljord, 1991; Finstad et al, 2000b)

Summary

Introduction

Determining the causes of spatio-temporal variation in life history traits among individuals is one of the main goals of ecology (Begon et al, 1996). In (Ovis canadensis), and Loison & Langvatn (1998) did Norway, the proportion of male red deer harvested not detect a relationship between winter severity during autumn each year declined with increasing and adult survival These observations show that snow depth in March (Mysterud et al, 2000). On the western side of the Atlantic, caribou, ters, body mass of moose in Sweden, where winter moose, muskox (Ovibos moschatus) and white-tailed weather was more continental, declined following deer abundance increased following high N A O warm, wet winters (Post & Stenseth, 1999) This (Table 2) in West Greenland, Isle Royale, East suggests that the effect of N A O on population Greenland and Minnesota respectively D d ruru etet erern n sssst nt sSsnetSeetsItttnnssetSeeIstSt, let.r.ealr.l.a,

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