AEROSPACE MAPPING OF THE STATUS AND POSITION OF NORTHERN FOREST LIMIT

Annika Hofgaard,Valentina Kravtsova,Olga Tutubalina

doi:10.24057/2071-9388-2012-5-3-28-47

Abstract

We study changes in the position of the northern forest limit and state of vegetation in the taiga-tundra ecotone through aerial and satellite imagery in the context of climate variability and of the projected advance of forests to the north. Our research of reference sites in Kola Peninsula and in Central Siberia has been part of PPS Arctic project of the International Polar Year. Studying the dynamics of ecotones by remote sensing is difficult due to poor display of ecotone vegetation in satellite images, and this required a range of techniques, regionally adapted and based on remotely sensed data of different spatial resolution. We characterize the newly developed techniques that enabled to identify vegetation change in recent decades: advance of forest up the slopes by 30 m in the Khibiny Mountains; advance of lichen-dwarf shrub tundra into lichen tundra in the north of Kola Peninsula; increasing stand density in sparse larch forests in the Khatanga River basin in the Taimyr Peninsula.

Highlights

The dynamics of the northern limit of forests have attracted attention in the context of climate change
Aerospace remote sensing provides an opportunity to accurately map the current structure of the taiga-tundra transition zone, as well as the dynamics of the northern forest line over the past decades
Defined boundaries of the northern forests, both on the ground and as depicted in the aerospace images, create difficulties in defining both the boundaries and their changes, and, in most cases, this transforms the problem to assessing the state of the transition zone between the tundra and taiga, and changes in the zone structure

Summary

Introduction

The dynamics of the northern limit of forests (and of their upper limit in the mountains) have attracted attention in the context of climate change. Availability of remotely-sensed imagery of required resolution and repeatability, along with the regional variability, determine the different methodological approaches to the use of aerospace imagery to study the dynamics of the northern forest line and the tundra-taiga ecotone.

Results

Conclusion