| dc.description.abstract | The High Arctic is currently going through large changes because of anthropogenic climate change. This includes direct changes like higher and more varied temperatures, as well as indirect changes such as changes in species composition and animal abundances. For animals living in Arctic soils, increased temperatures, more frequent winter rain events, and increased populations of geese will be important. This will in turn have consequences for the ecosystem services these animals provide, as well as the release of climate gasses from the soil to the atmosphere. Little is known, however, about how these changes will affect the soil invertebrates. There are no previous studies looking at how geese grubbing, where the geese dig up the ground in search of forage, affects Arctic soil invertebrates. Further, how winter rain events affect soil animals is still largely unresolved. In addition, it is likely that warming and winter rain events will affect soil invertebrates differently, depending on both habitat and whether the ground has been grubbed by geese. In this study, we established an experiment simulating the effects of warming, grubbing and winter rain events in two habitats close to Longyearbyen at Svalbard. I found geese grubbing to have a negative effect on invertebrate abundances in moss and Dryas-dominated tundra. Winter rain treatments were found to negatively affect Trombidiform mites and the Collembola Hypogastrura tullbergi in Dryas-dominated tundra, whereas no effects were recorded in the moss-dominated tundra. Similarly, warming was found to affect the abundances of Trombidiformes and the mesostigmatid mite family Ascidae in Dryas-dominated tundra. More invertebrate taxa were affected by treatments in the Dryas-dominated tundra than moss-dominated tundra. In plots simulating two treatments at once, the effect of each individual treatment was found to be both increased and decreased compared to the same treatments in single treatment plots. Overall, invertebrate taxa were found to react to all treatments, as well as reacting to combinations of different treatments in ways not predicted by each treatment alone. Furthermore, these reactions were found to vary between habitats. These results indicate future shifts in the Arctic soil invertebrate community and highlight the importance of considering both habitat as well as interactions between environmental factors when assessing how these populations will develop in the future. | |
