Profiles

Emelie Waldén

Emelie Waldén

Doktorand

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Arbetar vid Institutionen för naturgeografi
Telefon 08-674 78 64
E-post emelie.walden@natgeo.su.se
Besöksadress Svante Arrhenius väg 8
Rum V403
Postadress Inst för naturgeografi 106 91 Stockholm

Om mig

Emelie Waldén
Fil. Dr. Naturgeografi
Landskapsekolog

E-mail: emelie.walden@natgeo.su.se
Twitter: @EmelieWalden

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Länk till Forskningsenhet, Stockholms universitet
 

Forskning

Jag forskar om restaurering av naturbetesmarker i fragmenterade svenska landskap. I huvudsak studerar jag effekter på den biologiska mångfalden och ekosystemtjänster, men jag är även intresserad av jordbrukares och markägares perspektiv på naturbetesmarker och restaurering.

Publikationer

I urval från Stockholms universitets publikationsdatabas
  • 2018. Emelie Waldén (et al.).

    Humans play a major role shaping the living conditions for not only ourselves, but also all other species on Earth. In fact, some species-rich habitat types require human management to uphold the biodiversity and related ecosystem services. One of the world’s most biodiverse habitats on small spatial scales, semi-natural grasslands, have been formed over the course of centuries through extensive grazing and mowing. However, due to political and economic reasons, up to 90% of the European semi-natural grasslands have been lost during the 20th century. To counteract these drastic losses, restoration actions are implemented in environmental policies across Europe. Yet, knowledge of the long-term restoration effects on biodiversity and ecosystem services is still limited. The vast need for future restoration also requires a better understanding of how different pre-conditions affect the restoration outcome, as well as how stakeholders perceive restoration, to be able to prioritise between sites and recognise the limitations of the restoration process. In this thesis, I examine restoration outcomes in Swedish semi-natural grasslands, in terms of plant diversity, associated ecosystem services and from the farmers’ and land-owners’ perspective. The outcome is also analysed in relation to environmental factors at the local and landscape scale. I found that the overall community composition recovered to resemble intact reference communities, but it took relatively long time (12-20 years). Moreover, the reference sites still had higher species richness both at large and small spatial scales, more grassland specialist species and a higher abundance of plant species important to the five tested ecosystem services (meat production, pollination, water retention, temperature regulation and cultural heritage). My results show that prioritising large, unfertilised, newly abandoned grasslands situated in landscapes containing a large grassland specialist species pool and high amounts of intact and remnant semi-natural grasslands, could speed up the plant recovery. However, prioritising fast results does not necessarily ensure long-term success at a larger spatial scale. Since restoration success can be interpreted differently depending on evaluation measure used, pre-defined, clear and realistic goals are essential. While the surveyed farmers and landowners overall perceived the restoration as successful, 40% were unsure whether the grasslands will be managed in the future. Low profitability still poses a threat to their maintenance and thus, also to the coupled biodiversity and ecosystem services. Policy changes are therefore urgently needed to facilitate incentives for sustained management of restored and intact European semi-natural grasslands in a long-term perspective.

  • 2018. Alistair G. Auffret (et al.). Nature Communications 9

    Habitat loss through land-use change is the most pressing threat to biodiversity worldwide. European semi-natural grasslands have suffered an ongoing decline since the early twentieth century, but we have limited knowledge of how grassland loss has affected biodiversity across large spatial scales. We quantify land-use change over 50-70 years across a 175,000 km(2) super-region in southern Sweden, identifying a widespread loss of open cover and a homogenisation of landscape structure, although these patterns vary considerably depending on the historical composition of the landscape. Analysing species inventories from 46,796 semi-natural grasslands, our results indicate that habitat loss and degradation have resulted in a decline in grassland specialist plant species. Local factors are the best predictors of specialist richness, but the historical landscape predicts present-day richness better than the contemporary landscape. This supports the widespread existence of time-lagged biodiversity responses, indicating that further species losses could occur in the future.

  • 2017. Emelie Waldén (et al.). Biological Conservation 214, 176-183

    Habitat restoration is an important complement to protecting habitat for the conservation of biodiversity. Semi-natural grasslands are target habitats for ecological restoration in temperate Europe. Restoration of abandoned semi-natural grasslands often relies on spontaneous colonisation of plant species from the soil seed bank or the surrounding landscape. Although many studies show that the regional species pool is important for upholding local diversity, its effect on restoration outcome in semi-natural grasslands is poorly known. In this multi landscape study, we examined grassland specialist species occurring in restored grasslands and the effect of specialist species pool, landscape composition and local temporal factors. We found that specialist richness and frequency was positively affected by specialist richness and frequency in the surrounding landscape. Specialist richness in the restored grasslands also increased with time since restoration. Moreover, specialist frequency in the restored grassland increased with the proportion of semi-natural and remnant grassland habitats in the landscape. We also found a positive relationship between the proportion of species occurring in both the restored grassland and its surrounding landscape and time since restoration, in landscapes with high proportions of semi natural grasslands. This suggests that both temporal factors, as well as the landscape composition and species pool, affect plant recolonisation in restored semi-natural grasslands.

  • Artikel HistMapR
    2017. Alistair G. Auffret (et al.). Methods in Ecology and Evolution 8 (11), 1453-1457

    Habitat destruction and degradation represent serious threats to biodiversity, and quantification of land-use change over time is important for understanding the consequences of these changes to organisms and ecosystem service provision. Comparing land use between maps from different time periods allows estimation of the magnitude of habitat change in an area. However, digitizing historical maps manually is time-consuming and analyses of change are usually carried out at small spatial extents or at low resolutions. HistMapR contains a number of functions that can be used to semi-automatically digitize historical land use according to a map's colours, as defined by the RGB bands of the raster image. We test the method on different historical land-use map series and compare results to manual digitizations. Digitization is fast, and agreement with manually digitized maps of around 80-90% meets common targets for image classification. We hope that the ability to quickly classify large areas of historical land use will promote the inclusion of land-use change into analyses of biodiversity, species distributions and ecosystem services.

  • 2016. Emelie Waldén, Regina Lindborg. PLoS ONE 11 (5)

    Restoration is important for biodiversity conservation worldwide, but surprisingly little is known about its efficiency in a long-term perspective. In this study, we re-examined Swedish semi-natural grasslands 12-20 years after the restoration, by comparing field inventories of vascular plant species diversity made in 2001 with follow-up inventories in 2012. We also analysed restoration effect in relation to six environmental factors and used continuously managed semi-natural grasslands as references of desired state after restoration. We found that total species richness increased over time but not to reference levels, while there were no significant changes in species density or number of grassland specialists. However, the overall species composition in the restored sites, as well as grassland specialist composition, now largely resembled reference conditions. Fertilisation and time between abandonment and restoration were the only environmental variables that affected total species composition change, while site area affected change in grassland specialist composition. Our results show that restoration of semi-natural grasslands can contribute to conservation of semi-natural habitats and their associated biodiversity. Yet, due to the vague restoration goals for these sites, it is difficult to evaluate the restoration success, which emphasise the general need for clear and measurable goals.

Visa alla publikationer av Emelie Waldén vid Stockholms universitet

Senast uppdaterad: 30 september 2018

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