| 1. |
- Birkhofer, Klaus, et al.
(författare)
-
Conventional agriculture and not drought alters relationships between soil biota and functions
- 2021
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- Soil biodiversity constitutes the biological pillars of ecosystem services provided by soils worldwide. Soil life is threatened by intense agricultural management and shifts in climatic conditions as two important global change drivers which are not often jointly studied under field conditions. We addressed the effects of experimental short-term drought over the wheat growing season on soil organisms and ecosystem functions under organic and conventional farming in a Swiss long term trial. Our results suggest that activity and community metrics are suitable indicators for drought stress while microbial communities primarily responded to agricultural practices. Importantly, we found a significant loss of multiple pairwise positive and negative relationships between soil biota and process-related variables in response to conventional farming, but not in response to experimental drought. These results suggest a considerable weakening of the contribution of soil biota to ecosystem functions under long-term conventional agriculture. Independent of the farming system, experimental and seasonal (ambient) drought conditions directly affected soil biota and activity. A higher soil water content during early and intermediate stages of the growing season and a high number of significant relationships between soil biota to ecosystem functions suggest that organic farming provides a buffer against drought effects.
|
|
| 2. |
- Elmarsdóttir, Ásrún, et al.
(författare)
-
Effects of afforestation on biodiversity
- 2008
-
Ingår i: Affornord. Effects of afforestation on ecosystems, landscape and rural development. - 9789289317184 ; 562, s. 37-47
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 3. |
- Hall, Marianne, et al.
(författare)
-
Kollagring och markanvändning
- 2022
-
Ingår i: Markanvändning för en klimatpositiv framtid : En rapport om utmaningar och möjligheter i Skåne - En rapport om utmaningar och möjligheter i Skåne. - 9789198434989 - 9789198434996 ; , s. 6-12
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 4. |
- Hedlund, Katarina, et al.
(författare)
-
Utmaningar och möjligheter
- 2022
-
Ingår i: Markanvändning för en klimatpositiv framtid : En rapport om utmaningar och möjligheter i Skåne - En rapport om utmaningar och möjligheter i Skåne. - 9789198434996 - 9789198434989 ; , s. 48-60
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 5. |
- Hågvar, Sigmund, et al.
(författare)
-
Ecosystem birth near melting glaciers : A review on the pioneer role of ground-dwelling arthropods
- 2020
-
Ingår i: Insects. - : MDPI AG. - 2075-4450. ; 11:9, s. 1-35
-
Forskningsöversikt (refereegranskat)abstract
- As glaciers retreat, their forelands represent “natural laboratories” for the study of primary succession. This review describes how certain arthropods conquer pristine ground and develop food webs before the establishment of vascular plants. Based on soil samples, pitfall traps, fallout and sticky traps, gut content studies, and some unpublished data, we compare early arthropod succession on glacial forelands of northern Europe (Iceland, Norway including Svalbard, and Sweden) and of the Alps (Austria, Italy). While macroarthropod predators like ground beetles (Coleoptera: Carabidae), harvestmen (Arachnida: Opiliones), and spiders (Arachnida: Araneae) have usually been considered as pioneers, assumed to feed on airborne prey, this review explains a different pattern. Here, we highlight that springtails (Collembola), probably feeding on biofilm made up of algae or cyanobacteria, are super-pioneers, even at high altitudes and under arctic conditions. We also point out that macroarthropod predators can use locally available prey, such as springtails or non-biting midges (Diptera: Chironomidae). Pioneer arthropod communities vary under different biogeographical and climatic conditions. Two pioneer food webs, from northern Europe and the Alps, respectively, differed in structure and function. However, certain genera and orders were common to both. Generalists and specialists live together in a pioneer community. Cold-adapted specialists are threatened by glacier melting.
|
|
| 6. |
- Ingimarsdottir, Maria
(författare)
-
Community and food web assembly on virgin habitat islands - The nunatak saga
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The classical view of primary community assembly is that colonisation by plants is essential before invertebrates can establish. It has been recognised, however, that invertebrates can establish before plants, and that they may be important in the first steps of community assembly. Plant succession is well studied but assembly of invertebrates and how their dispersal abilities affect the community assembly has, so far, gained less attention. The thesis adresses the questions: Does isolation decrease the rate of community assembly? Do invertebrates use corridors to direct their dispersal? What are the food resources of predators on new land? Is the assembly of communities more controlled by dispersal or the environment? Communities were studied along chronosequences on recently emerged nunataks (ice-free land in glacial areas) in Iceland. Each nunatak has a community assembly that starts with long distance dispersal from other terrestrial environments. This allowed a study on both local community and food web assembly, and on the effect of geographical isolation on this process. To determine ways of dispersal, invertebrates were collected on the glacier, lowland and on medial moraines. Medial moraines form corridors of debris on the glacier that stretch from the nunataks to the lowland. They directed the dispersal of flies that were moving over the glacier, to the nunataks and down to the lowland. When the rate of the community assembly on the nunataks was compared with that of non-isolated areas, no difference was observed. This indicates that isolation is not restricting the rate of community assembly, at least not of the first colonisers. Environmental gradients thus have a strong effect on the assembly of communities, compared to dispersal constraints. However, dispersal may restrict the colonisation of larger invertebrates, which are not as widespread on the nunataks. The first colonisers are small invertebrate predators and detritivores and when plants start to establish, more trophic groups can be added to the food webs, like herbivores and their predators. More invertebrates arrived at the nunataks than established and these may make up an important part of the food web, especially where primary productivity is lacking. By using the technique of stable isotopes, it was shown that early colonising predators feed on prey that is of a geographically distant origin. Perhaps, some of the predators are of a distant origin themselves. This thesis shows that dispersal abilities of many invertebrates is large and isolated areas are therefore not always as isolated as we may think.
|
|
| 7. |
- Ingimarsdottir, Maria, et al.
(författare)
-
Corridor or drift fence? The role of medial moraines for fly dispersal over glacier
- 2013
-
Ingår i: Polar Biology. - : Springer Science and Business Media LLC. - 1432-2056 .- 0722-4060. ; 36:7, s. 925-932
-
Tidskriftsartikel (refereegranskat)abstract
- Corridors are often considered to promote dispersal between habitat patches. In this paper, we study whether or not corridors induce colonisation of nunataks (ice-free areas in glacier surroundings) by promoting dispersal from lowland to the nunataks. On outlet glaciers, debris originating from nunataks forms the so-called medial moraines that stretch from the nunataks down-glacier to the lowland, forming corridors of debris on the glacier. Aerial dispersal was determined with yellow sticky traps on the moraines, bare glacier and glacier foreland. Dipterans were sampled in pitfall traps on the nunataks. Flying insects that were present on the vegetated glacier foreland belonged to five orders, that is, Diptera, Hemiptera, Hymenoptera, Lepidoptera and Trichoptera. On the glacier and medial moraines, however, mainly dipterans were present, with the majority of individuals found on the moraines. Hoverflies (Syrphidae) were abundant on the moraines and on the edges of nunataks close to the moraines, but were not present on the vegetated foreland. The origin of the hoverflies is thus not the nunataks and not the lowland. Rather, they are brought in by air currents towards the glacier, where they aggregate on a land type where they have a chance of survival, although it is not habitable. Thus, we conclude that the medial moraines do not function as regular corridors but as drift fences that direct the dispersal towards the adjacent land types, that is, the nunataks and the glacier foreland.
|
|
| 8. |
- Ingimarsdottir, Maria, et al.
(författare)
-
Food sources of early colonising arthropods: The importance of allochthonous input
- 2014
-
Ingår i: Pedobiologia. - : Elsevier BV. - 1873-1511 .- 0031-4056. ; 57:1, s. 21-26
-
Tidskriftsartikel (refereegranskat)abstract
- Arthropod predators and detritivores are among the first colonisers on land surfaces undergoing primary succession. In the absence of higher plants and herbivores, they may either have an allochthonous food source (i.e. of geographically distant origin) or local food source that is sustained by e.g. microorganisms. By studying spiders and collembolans on sites along chronosequences on recently emerged nunataks (ice-free land in glacial areas), we analysed whether the food source of early colonisers was of local or distant origin. Also, we measured the potential changes in trophic position with increasing site age. With stable carbon and nitrogen isotope analysis of both spiders and collembolans, we determined that allochthonous food sources are important on the youngest sites. The allochthonous food sources may explain how arthropods can persist in the absence of local primary productivity. Also, some spider species may increase their ability to survive by shifting their trophic position as the community composition changes. The results indicate that a wolf spider species shifted towards a lower trophic level with increasing site age. By contrast, no shifts in trophic position were observed for sheet-web spiders or collembolans.
|
|
| 9. |
- Ingimarsdottir, Maria, et al.
(författare)
-
Food web assembly in isolated habitats: A study from recently emerged nunataks, Iceland
- 2013
-
Ingår i: Basic and Applied Ecology. - : Elsevier BV. - 1618-0089 .- 1439-1791. ; 14:2, s. 174-183
-
Tidskriftsartikel (refereegranskat)abstract
- Allochthonous arthropods can sustain a local food web on seemingly barren land, but are nevertheless often neglected in studies of community assembly. In the present study, we investigated primary food web assembly on nunataks (ice-free areas) in a retreating glacier in Iceland. Nunataks enable studies that take into account both the temporal factor of the assembly and the influx of allochthonous organisms. Arthropods were collected on sites of different age on five nunataks younger than 70 years, as well as the youngest parts of one old nunatak. The youngest sites had no vegetation and were dominated by detritivores and predators along with allochthonous arthropods. The arthropod biomass, that was considered established, increased with vegetation cover and site age but also differed among nunataks. To investigate whether or not the assembly of arthropods was consistent with the predictions of assembly rules, we tested whether, (1) the proportion of each trophic level changed non-randomly, (2) predator-prey ratio remained constant, and (3) larger species replaced smaller ones. We could only verify that proportions of trophic levels changed non-randomly. As assembly rules only apply for established organisms, it is possible that difficulties in determining whether e. g. generalist predators were established or not may affect the outcome of analyses of assembly rules. It is thus important to be aware that unintentional inclusion of allochthonous arthropods in models of community assembly may affect whether or not the community can be explained and predicted by assembly rules.
|
|
| 10. |
- Ingimarsdottir, Maria, et al.
(författare)
-
Primary assembly of soil communities: disentangling the effect of dispersal and local environment.
- 2012
-
Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 1432-1939 .- 0029-8549. ; 170:3, s. 745-754
-
Tidskriftsartikel (refereegranskat)abstract
- It has long been recognised that dispersal abilities and environmental factors are important in shaping invertebrate communities, but their relative importance for primary soil community assembly has not yet been disentangled. By studying soil communities along chronosequences on four recently emerged nunataks (ice-free land in glacial areas) in Iceland, we replicated environmental conditions spatially at various geographical distances. This allowed us to determine the underlying factors of primary community assembly with the help of metacommunity theories that predict different levels of dispersal constraints and effects of the local environment. Comparing community assembly of the nunataks with that of non-isolated deglaciated areas indicated that isolation of a few kilometres did not affect the colonisation of the soil invertebrates. When accounting for effects of geographical distances, soil age and plant richness explained a significant part of the variance observed in the distribution of the oribatid mites and collembola communities, respectively. Furthermore, null model analyses revealed less co-occurrence than expected by chance and also convergence in the body size ratio of co-occurring oribatids, which is consistent with species sorting. Geographical distances influenced species composition, indicating that the community is also assembled by dispersal, e.g. mass effect. When all the results are linked together, they demonstrate that local environmental factors are important in structuring the soil community assembly, but are accompanied with effects of dispersal that may "override" the visible effect of the local environment.
|
|
| 11. |
-
Markanvändning för en klimatpositiv framtid : En rapport om möjligheter och utmaningar i Skåne
- 2022
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport är en sammanställning och analys av kunskapsläget när det gäller ekosystembaserade metoder för att minska utsläpp och öka upptag av koldioxid hos brukade marker i Skåne. Med fokus på markanvändning och skötselstrategier inom jordbruk och skogsbruk, samt användning av biokol, analyseras och bedöms potentialen för att inom Skånes gränser öka upptag respektive minska utsläpp av kol från dessa ekosystem. Syftet är att analysera hur möjligheter som föreslås av den statliga utredningen SOU 2020:4, Vägen till en klimatpositiv framtid, kan omsättas till en skånsk kontext i ett miljömässigt/ekologiskt perspektiv.Rapporten är ett samverkansprojekt mellan Lunds universitets Centrum för miljö- och klimatvetenskap och Region Skåne, och har finansierats med medel från Region Skåne, det strategiska forskningsområdet BECC – Biodiversity and Ecosystem Services in a Changing Climate, Lunds universitets samverkansinitiativ LU Land, samt Centrum för miljö- och klimatvetenskap.
|
|
