دانلود رایگان مقاله انگلیسی اثرات لاشه آبزیان مهاجم در شیمی خاک و جوامع میکروب زمینی - اشپرینگر 2017

Abstract

Carrion plays a crucial role in the recycling of nutrients and organic matter in ecosystems. Yet, despite their ecological importance, studies addressing the relevance of carrion originated from invasive alien species (IAS) in the interface between aquatic and terrestrial ecosystems are uncommon, especially those assessing belowground effects. In this study, we carried out a manipulative experiment to assess the impact of massive mortalities of the Asian clam Corbicula fluminea (Mu¨ller, 1774) as a carrion subsidy evaluating possible effects on the terrestrial soil chemistry and the structure of a microbial (bacteria and fungi) community. We placed five levels of C. fluminea density (0, 100, 500, 1000 and 2000 ind. m-2 ) and samples were collected 7, 30 and 90 days after clams’ addition. The results revealed that C. fluminea carrion have a significant effect belowground, especially on nutrients content (mainly NH4 ?, NO2 -, NO3 - and PO4 3-), fungal biomass and fungal and bacterial diversity. Given the predicted increase and intensification of extreme climatic events and the widespread distribution of several aquatic IAS (including bivalve species such as C. fluminea) the ecological importance of these massive mortalities (and resulting carrion) cannot be ignored because they may affect microbial communities with significant impacts on nutrient cycling, even in adjacent terrestrial habitats.

Conclusion

Overall, our results revealed that the decomposition of C. fluminea carrion has significant effects belowground, including on nutrients content, fungal biomass and fungal and bacterial diversity. These results are particularly important when viewed across entire landscapes. Indeed, in highly invaded aquatic ecosystems, massive mortalities of C. fluminea may change soil chemistry, nutrient cycling and microbial communities even in adjacent terrestrial areas. Although our approach tried to mimic an extreme climatic event resulting from a flood, recent studies showed that massive mortalities of C. fluminea also occurred during drought events (Bo´dis et al. 2014; McDowell et al. 2017) and this situation can also significantly affect aquatic ecosystem functioning. Given the predicted increase and intensification of extreme climatic events (e.g. heatwaves, floods and droughts) and the widespread distribution of several aquatic IAS in the future, the ecological importance of these massive mortalities (and resulting carrion) cannot be ignored and should be investigated in more detail.