Land use and Climate driven Land use and Climate driven alternation of trophic interactions alternation of trophic interactions in tundra ecosystems: an alpine in tundra ecosystems: an alpine

example from 62example from 62ooNN

Annika HofgaardArctic Change 2008, Quebec, 10 December 2008

Annika Hofgaard (coordinator)Nina Eide, Graciela RuschRoel May, Dagmar Hagen

Lars Erikstad, Duncan HalleyJan-Ove

Gjershaug, Jiska van DijkBodil

Wilmann

Norwegian Institute for Nature Research

(NINA)

Funding

Research Council of Norway, Strategic Institute Program 2007-2010

Alpine 62Alpine 62°°NN

Project group

AimBackgroundGeneral ecosystem servicesProject design

–

Region–

Methods

–

Trophic levels

Preliminary results

Today!Alpine 62Alpine 62°°NN

“Alpine 62oN” is a regional scale project aiming at deepening knowledge on climate and land use driven changes in trophic interactions and consequences for ecosystem services

Project aimAlpine 62Alpine 62°°NN

Demands for goods and services from tundra systems is multifold and in constant changeTundra areas are regionally exposed to intense human use but large parts of the Arctic still has low degree of exploitationChange is to come at a broad scale around the circumpolar north in time with changed sea routes, improved accessibility to arctic resources, and increased tourism

BackgroundAlpine 62Alpine 62°°NN

Intensified land use ultimately will change alpine and arctic systems from being primarily climate driven to being climate and land use driven Land use will, hypothetically, move towards the role of a more dominant ecosystem driver although the speed will vary among trophic levels and climatic regions Central question: To what degree is climate an ecosystem driver in regions with multifold human use?

BackgroundAlpine 62Alpine 62°°NN

Conceptual framework

Ecosystem states

Environmentalpressures

Impacts

EcosystemResponses

Natural Driver Climate

Socioeconomic DriverLand use

Society responses

Alpine 62Alpine 62°°NN

Ecosystem servicesDrivers

PressuresStates

ImpactsResponses

Top-

down

٧Bo

ttom

-up

regu

lati

on?

Local:food, pasture, tourism

Regional:water resources, snowduration & distribution

Global:albedo –

feedback to climate

FoodHuntingTourism

TourismEcosystem regulation?Conflicts?

Processes and functions with importance to the environment we are depending on

Climate ٧ Land useregulation?

Baseline environmental and land use data derived from digital cartography, DEMs

and

other geo-referenced data

Sampled biological data in randomly selected sets of 1x1 km grid units in three alpine regions in central Norway with oceanic, intermediate and continental climates, respectively

Project designAlpine 62Alpine 62°°NN

120 km

oceanic

continental

intermediate

Alpine 62Alpine 62°°NN

Environmental & land use data:altitudelandscape mosaic (e.g. abundance

of water bodies and mires) terrain ruggednessclimate sectionmeteorological datasnow cover regimedistance to forest covered areasproportion of shrub covered areasdistance to roads, power lines andbuildings

frequency and timing of grazingby domestic and semi-domestic animals

hunting and legal carnivorepopulation regulation

The biological data

includes numerous variables linked to four key biotic components

representing different trophic levels:

Vegetation (species composition, physiognomic structure, recruitment after disturbance)

Herbivores (voles, lemming, hare, sheep, reindeer)

Small and meso-carnivores(mustelids, arctic fox, red fox)

Large carnivore (one species: wolverine)

Carbon and nitrogen flowthrough selected food chains are quantified through stable isotope analysis

Climate gradient–

Vegetation structure

–

Recruitment after disturbance–

Structure across the treeline zone

–

Herbivore presence/frequency–

Snow conditions and wolverine breeding

–

Predator presence/frequency–

Carbon and nitrogen flow (vegetation)

Ongoing analysesAlpine 62Alpine 62°°NN

Upcoming analysesAlpine 62Alpine 62°°NN

Land use gradient

Ecosystem structure at spatial,environmental and temporal scales

Development of conceptual landscape model and predictive models andscenarios for future change

Top-down ٧ Bottom-up regulation

Climate ٧ Land use regulation

Thanks !

Questions ?