**Main Ecosystem Characteristics and Distribution of Wetlands in Boreal and Alpine Landscapes in Northern Sweden Under Climate Change**

J. Jeglum, S. Sandring, P. Christensen, A. Glimskär, A. Allard, L. Nilsson and J. Svensson *Swedish University of Agricultural Sciences Sweden* 

#### **1. Introduction**

192 Ecosystems Biodiversity

Kremer, P. and Nixon, S. 1976. Distribution and abundance of the ctenophore *Mnemiopsisleidyi* in Narragansett Bay. Estuar. coast. mar. Sci. 4: 627-639. Kremer, P. M. 1993. Ctenophore population dynamics: patterns of abundance for *Mnemiopsis* 

Prodanov, K., Mikhailov, K. G., Daskalov, K., Chashchin, A., Arkhipov, A., Shlyakhov, V.

Roohi, A. 2000. An introduction to the some ecological aspects of the new alien ctenophore

Roohi A., Zulfigar Y., Kideys A., Aileen T., Ganjian A., and Eker-Develi E. 2008a. Impact of

Roohi A., Zulfigar Y., Kideys A., Aileen T., Eker-Develi E., Ganjian A., Nasrollazadeh H.

Roohi A., Kideys A., Sajjadi A., Hashemian A., Pourgholam R., Fazli H., Ganjian Khanari

Shiganova, T. A., Bulgakova, J. V, Volovik, S. P, Mirzoyan, Z. A. and Dudkin, S. I. 2001b. A

Shiganova, T., Dumont, H., Sokolsky, A., Kamakin, A., Tinenkova, D. and Kurasheva, A.

Shiganova, T., Mirzoyan, Z., Studenikina, E., Volovik, S., Siokoi-Frangou, I., Zervoudaki, S.,

Studenikina, E. I., Volovik, S. P., Miryozan, I. A. And Luts, G. I. 1991. The ctenophore

UNDP Project Document, Governments of: Azerbaijan, Islamic Republic of Iran,

Yunev OA, Carstensen J, Moncheva S, Khaliulin A, Aerteb- jerg G, Nixon S. 2002. Nutrient

eutrophication and climate changes. Estuar Coast Shelf Sci 74:63-76

other seas of the Mediterranean basin. Marine biology, 139:431-445.

*Mnemiopsis leidyi* in the Sea of Azov. Oceanology 3: 722-725.

and Ozdamar, E. 1997. Environmental impact on fish resources in the Black Sea. In: Ozsoy E, Mikaelyan A (eds) Sensitivity of the North Sea, Baltic Sea and Black Sea to

*Mnemiopsis leidyi* in the Southern Caspian Sea, Caspian Sea Research Institute of

a new invader ctenophore *Mnemiopsis leidyi* on the zooplankton of the southern

2008b. Environmental changes due to a new allein comb jelly, *Mnemiopsis leidyi* in the Southern Caspian Sea, International conference on environmental research and

A. and Eker-Develi E. 2010. Changes in biodiversity of phytoplankton, zooplankton, fishes and macrobenthos in the Southern Caspian Sea after the invasion of the ctenophore Mnemiopsis Leidyi, Biological Invasions, 12: 2343- 2361 Seravin, L. N. 1994. The systematic revision of the genus Mnemiopsis (Ctenophora, Lobata).

new invader, *Beroe ovata* Mayer 1912 and its effect on the ecosystems of the Black and Azov Seas in August-September 1999. Kluwer Ac.pub .

2004. Aquatic Invasions in the Black, Caspian, and Mediterranean Seas, 71–111.

Christou, E., Skirta, A. and Dumont, H. 2001a. A review of the invader ctenophore *Mnemiopsis leidyi* ( A.Agassiz) population development in the Black Sea and in the

Kazakhstan, Russian Federation & Turkmenistan, United Nations Development Programme, PIMS #4058, The Caspian Sea: Restoring Depleted Fisheries and Consolidation of a Permanent Regional Environmental Governance Framework, "CaspEco", www.caspianenvironment.org/newsite/Data-MajorDocuments.htm. Vinogradov, M. E., E. A. Shushkina, E. I. Musaeva & P. Yu. Sorokin,.1989. Ctenophore

*Mnemiopsis leidyi* (A. Agassiz) (Ctenophora: Lobata) - new settlers in the Black Sea.

and phytoplankton trends on the western Black Sea shelf in response to cultural

*leidyi* in U.S. coastal waters. ICES Statutory meeting L.36: 1-9.

Caspian Sea, *Marine Ecology,* Vol. 29, No. 4, pp. 421-434.

technology (ICERT 08), 28-30 MAY 2008, Penang, Malaysia.

Ecology, Tehran, Iran.

Zool. Zhurnal 73: 9-18 (in Russian).

Kluwer Academic Publishers, Netherlands.

Hydrobiologia, 451: 187-197.

Oceanology 29: 293-298.

anthropogenic and climatic changes. Kluwer, Dordrecht p 163–181.

Wetlands and peatlands are integral parts of many of the world's biomes, forming important transition zones between upland and aquatic systems. These habitats have a high degree of complexity of hydrology, edaphic conditions, and vegetation composition, contributing to the biodiversity of landscapes and species richness. They act to influence and modify the movement of runoff and groundwater from uplands into streams and lakes, by laying down organic remains (peats), and absorbing and releasing elements, compounds, gases, and particulate and dissolved organic matter. They therefore act as hydrological water retainers and biological filters in the landscape.

Many kinds of wetlands and peatlands can be found, each with a particular hydrology and surface form, moisture and chemical regime, and range of vegetation types and associated biota. Owing to their hydrological characteristics, predominantly peat soils and hydrophytic plants, wetlands and peatlands are key habitats to indicate climate change, particularly changes towards drying (e.g., decreased precipitation, increased runoff from melting glaciers and snow pack). Changes in moisture regime will effect changes in the processes of peat accumulation and decomposition, release of nutrients and dissolved organic matter, and vegetation and species. Drainage for agriculture and forestry, peat harvesting, and development have already caused considerable areas of peatlands to decrease in depth and area. Owing to drying, some peatlands adjacent to uplands have decreased in depth to less than 30 cm, the defined depth for peatlands in Sweden, and thus the total area of peatland has decreased.

Drying also has caused changes in vegetation, for examples, advances of trees and shrubs from the margins into the centres of peatlands (e.g., Fig. 1; cf. Hebda et al., 2000; Linderholm & Leine, 2004), and the dying of Sphagnum by lowered water levels and being covered over by leaf litter. Hebda *et al.* estimated the zone of influence of water lowering in Burns Bog, a bog on the Fraser River Delta in southern British Columbia, Canada, to extend over 100 m from a peripheral ditch. The Swedish Wetland Inventory, VMI, (Gunnarsson & Löfroth, 2009) was conducted during 25 years and generated results that indicate that about 15% of

Main Ecosystem Characteristics and Distribution of Wetlands

the context of biodiversity on multiple scales.

**2.1 Characteristics of the elevation zones** 

hence, the alpine tree line.

as the basis for summarizing wetland and peatland data (Fig. 2).

biodiversity.

**2. Study area** 

in Boreal and Alpine Landscapes in Northern Sweden Under Climate Change 195

Asada, 2006; Strack, 2008). European climate models predict increases in warm indices and decreases in cold indices (Persson et al., 2007; Lind & Kjellström, 2008). Higher summer temperatures will promote higher evapotranspiration in the summer, resulting in deeper water tables in the wetlands. Relatively higher warming is expected for the interior in northern Sweden. On the other hand, there are predicted to be increases in wet indices in the north and dry indices in the south, and this may lessen the impacts of drying on wetlands in the north, and accentuate impacts of drying on wetlands in the south. Trends and trajectories are largely unknown, however, as are the influences on natural conditions and

The National Inventory of Landscapes in Sweden (NILS) has undertaken to monitor landscape changes owing to natural and anthropogenic disturbances, and ecological processes at the landscape scale (Svensson et al., 2009; Ståhl et al., 2011). NILS encompasses all terrestrial habitats in Sweden, and includes mapping of peatland and wetland types and characterizing the tree, shrub, field and ground vegetation, and surfaces. One of the main incentives behind NILS is to capture relevant data and provide analyses to answer the national Environmental Quality Objectives, of which the "Thriving wetlands" objective concerns the conservation and restoration of peatlands (e.g. Government of Sweden, 2009). The aims of this chapter are to elucidate multiple-scale biodiversity aspects – i.e. landscape, community-ecosystem, population-species (Noss, 1990) – through area and distribution of wetlands and peatlands in northern Sweden; area and distribution of the Hydrotopographic types; and associated vegetation strata and ground conditions associated with the Hydrotopographic types. We include a discussion of the value of the NILS monitoring of the wetlands for assessing climate changes and other changes owing to anthropogenic causes in

The study area is situated in the northern part of Sweden, coinciding with the two northernmost counties of Västerbotten and Norrbotten (Fig. 3). The landscape ranges from the coastal boreal areas consisting of often flat forested areas, up through the interior with a mixture of boreal forest and mires, to the mountains and birch-forested valleys of the Scandes Mountains. The study area has been classified into Natural Geographic Regions, sometimes referred to as Biogeographical Regions, according to the Nordic Council of Ministers (1977), Helmfrid (1996), and Lennartsson & Stighäll (2005). These regions were chosen as they take into account both east-west and north-south variations. As we wanted to study the distribution in the context of occurrences at different elevations as well as the climatic aspect, the regions were regrouped into five Elevation Zones which then were used

**Zone 1. The Arctic/Alpine zone** has steep mountains with glaciers and vegetation zones at lower altitudes. The prevailing Atlantic wind and precipitation provide strong climatic differences between westward slopes and eastward facing slopes with more continental climates. Nutrients in the bedrock and soil are varied and the soil layers are usually very thin. The zone encompasses the gradual shift from forest to treeless alpine habitats, and,

mires in the northern part of Sweden are strongly influenced or even destroyed, and 55% are weakly influenced while the rest are considered uninfluenced by human impact. Impacts are mainly from machines used for forestry and the digging of ditches. Small mires and mires in the Scandinavian Mountain Range were not covered by the VMI, however, and it may be assumed that processes such as increased tree cover or successional shifts to other vegetation types are more evident in such habitats. The main threats to the mountainous mires are tracks from all-terrain vehicles and snowmobiles, and much concern has been expressed from County Boards and the Swedish Environmental Protection Agency about this issue (e.g. Renman, 1989; Allard et al., 2004).

Fig. 1. A significant proportion of the arable land in Sweden has been created through drainage of wetlands. The figure (Color Infra Red aerial photo) shows an area in southern Sweden. The farm buildings are placed on the uplands in the SE corner and the wetlands have been drained and form long rectangular arable fields (light tones). Trees and shrubs (pink tones) now invade along the ditches and into the center of some fields as a result of decreasing land use intensity. The area above the drained fields shows invasion of trees and shrubs on a previously open string flark fen.

It is generally anticipated that climate change will cause considerable impacts and changes on landscapes and ecosystems. Dale et al. (2001) provide a review of the impacts of climate change on forests, which included altering the frequency, intensity, duration, and timing of fire; drought; introduced species; insect and pathogen outbreaks; hurricanes, windstorms, ice storms; and landslides. Similar impacts may be expected in peatlands. Several reviews on predicted impacts of climate change on wetlands and peatlands have been published (Gorham, 1991; 1995; Gorham et al., 2001; Strack et al., 2004; Tarnocai, 2006; Warner & Asada, 2006; Strack, 2008). European climate models predict increases in warm indices and decreases in cold indices (Persson et al., 2007; Lind & Kjellström, 2008). Higher summer temperatures will promote higher evapotranspiration in the summer, resulting in deeper water tables in the wetlands. Relatively higher warming is expected for the interior in northern Sweden. On the other hand, there are predicted to be increases in wet indices in the north and dry indices in the south, and this may lessen the impacts of drying on wetlands in the north, and accentuate impacts of drying on wetlands in the south. Trends and trajectories are largely unknown, however, as are the influences on natural conditions and biodiversity.

The National Inventory of Landscapes in Sweden (NILS) has undertaken to monitor landscape changes owing to natural and anthropogenic disturbances, and ecological processes at the landscape scale (Svensson et al., 2009; Ståhl et al., 2011). NILS encompasses all terrestrial habitats in Sweden, and includes mapping of peatland and wetland types and characterizing the tree, shrub, field and ground vegetation, and surfaces. One of the main incentives behind NILS is to capture relevant data and provide analyses to answer the national Environmental Quality Objectives, of which the "Thriving wetlands" objective concerns the conservation and restoration of peatlands (e.g. Government of Sweden, 2009).

The aims of this chapter are to elucidate multiple-scale biodiversity aspects – i.e. landscape, community-ecosystem, population-species (Noss, 1990) – through area and distribution of wetlands and peatlands in northern Sweden; area and distribution of the Hydrotopographic types; and associated vegetation strata and ground conditions associated with the Hydrotopographic types. We include a discussion of the value of the NILS monitoring of the wetlands for assessing climate changes and other changes owing to anthropogenic causes in the context of biodiversity on multiple scales.
