Sökresultat

Remote sensing provides spatially and temporally continuous measures of forest reflectance, and vegetation indices calculated from satellite data can be useful for monitoring climate change impacts on forest tree phenology. Monitoring of evergreen coniferous forest is more difficult than monitoring of deciduous forest, as the new buds only account for a small proportion of the green biomass, and t

Time series of satellite sensor-derived data can be used in the light use efficiency (LUE) model for gross primary productivity (GPP). The LUE model and a closely related linear regression model were studied at an ombrotrophic peatland in southern Sweden. Eddy covariance and chamber GPP, incoming and reflected photosynthetic photon flux density (PPFD), field-measured spectral reflectance, and data

Current forest Free Air CO2 Enrichment (FACE) experiments are reaching completion. Therefore, it is time to define the scientific goals and priorities of future experimental facilities. In this opinion article, we discuss the following three overarching issues (i) What are the most urgent scientific questions and how can they be addressed? (ii) What forest ecosystems should be investigated? (iii)

Summary *Here, species composition and biomass production of actively growing ectomycorrhizal (EM) mycelia were studied over the rotation period of managed Norway spruce (Picea abies) stands in south-western Sweden. *The EM mycelia were collected using ingrowth mesh bags incubated in the forest soil during one growing season. Fungal biomass was estimated by ergosterol analysis and the EM species w

Animals possess different abilities to gain and use information about the foraging patches they exploit. When ignorant of the qualities of encountered patches, a smart forager Should leave all patches after the same amount of fixed search time. A smarter forager can be Bayesian by using information Oil Cumulative harvest and time spent searching a patch to better inform its patch-departure decisio

A detailed understanding of the influence of temperature on soil microbial activity is critical to predict future atmospheric CO2 concentrations and feedbacks to anthropogenic warming. We investigated soils exposed to 3-4 years of continuous 5 degrees C-warming in a field experiment in a temperate forest. We found that an index for the temperature adaptation of the microbial community, T-min for b

Currently, we are experiencing biodiversity loss on different spatial scales. One of the best studied taxonomic groups in decline is the butterflies. Here, we review evidence for such declines using five systematic studies from southern Sweden that compare old butterfly surveys with the current situation. Additionally, we provide data on butterfly and burnet moth extinctions in the region’s counti

The evolution of striking phenotypes on islands is a well-known phenomenon, and there has been a long-standing debate on the patterns of body size evolution on islands. The ecological causes driving divergence in insular populations are, however, poorly understood. Reduced predator fauna is expected to lower escape propensity, increase body size and relax selection for crypsis in small-bodied, ins

In order to investigate the potential role of vegetation changes in megafaunal extinctions during the later part of the last glacial stage and early Holocene (42-10 ka BP), the palaeovegetation of northern Eurasia and Alaska was simulated using the LPJ-GUESS dynamic vegetation model. Palaeoclimatic driving data were derived from simulations made for 22 time slices using the Hadley Centre Unified M

Rigorous and widely applicable indicators of biodiversity are needed to monitor the responses of ecosystems to global change and design effective conservation schemes. Among the potential indicators of biodiversity, those based on the functional traits of species and communities are interesting because they can be generalized to similar habitats and can be assessed by relatively rapid field assess

Soil nitrogen (N) availability constrains future predictions of ecosystem primary productivity and carbon storage. The progressive N limitation (PNL) hypothesis predicts that forest net primary productivity (NPP) will decline with age, and that the response of NPP to elevated CO2 will attenuate through time due to negative feedbacks of NPP on the soil N cycle. A central assumption of the PNL hypot

In 2005 and 2010 the Amazon basin experienced two strong droughts', driven by shifts in the tropical hydrological regime(2) possibly associated with global climate change(3), as predicted by some global models'. Tree mortality increased after the 2005 drought(4), and regional atmospheric inversion modelling showed basin-wide decreases in CO2 uptake in 2010 compared with 2011 (ref. 5). But the resp

We investigated the impact of biochar application on fungal (acetate incorporation into ergosterol) and bacterial (leucine incorporation) growth rates in two case studies: a temperate UK pasture soil and a Mediterranean Australian agricultural soil. We added biochar at similar rates per unit of soil organic carbon (SOC) and monitored both the immediate (after 1week equilibration) and longer-term (

Soil water chemistry in forest soils over 20years was studied at nine sites in southern Sweden. The aim was to investigate the recovery from acidification and the influence of strong sea salt episodes that occur in the region. All sites but one showed signs of recovery from acidification along with the reduced sulphur deposition, but the recovery progress was slow and the soil water was in most ca

Agricultural intensification in Europe has affected farmland bird populations negatively, both during summer and winter. Although the migratory period poses separate challenges on birds than breeding and wintering, the consequences of farming practices for birds during migration remain poorly investigated. We monitored abundance and species richness of migratory birds in autumn at matched pairs of

When searching for resources in heterogeneous environments, animals must rely on their abilities to detect the resources via their sensory systems. However, variation in the strength of the sensory cue may be mediated by the physical size of the resource patch. Patch detection of insects are often predicted by the scaling of sensory cues to patch size, where visual cues has been proposed to scale

1. Freshwater communities are often structured by predation. In permanent lentic freshwater habitats dragonfly larvae are major predators which, in return, suffer predation by fish. Antipredator traits vary between the dragonfly species, and the dragonfly communities are therefore shaped by the presence of fish. But fish communities vary, and as different fish species affect dragonflies in differe

We have measured the land-atmosphere CO2 exchange using the eddy covariance technique in a high Arctic tundra heath in northeast Greenland (Zackenberg). On the basis of 11 years of measurements (2000-2010), it was found that snow cover dynamics was important for the CO2 exchange. The start of CO2 uptake period correlated significantly with timing of snowmelt. Furthermore, for years with deep and l