Since this month (April) is the ‘Earth Month’, let’s spread the word about how our biodiversity is declining and endangered.
Biodiversity has declined rapidly worldwide and that is a fact! According to the World Wildlife Fund’s (WWF) Living Planet Report 2016, between the years of 1970 and 2012, there was a staggering decline of 58% of vertebrate populations (WWF 2016). Reasons for the decline are manifold. For instance, habitat destruction and fragmentation, agriculture and the use of herbicides, land use changes, pollution, introduction of exotic species and overexploitation by hunting, fishing… Each of these actions play their role in the biodiversity decline. Also, the ongoing global warming poses a serious risk to all of the Earth’s biota (IPCC 2013).
Northern ecosystems, especially freshwaters, and their biodiversity are considered to be highly sensitive to different anthropogenic stressors (IPCC 2013; Vilmi et al. 2017). However, Northern regions have still managed to remain relatively undisturbed compared to more southern parts of the world. Unfortunately, this may change in the future as high-latitude areas have also been projected to be greatly affected by the environmental changes caused by the ongoing climate change (IPCC 2013).
The Biodiversity Investigators Group was involved (together with other guys) in conducting a review about the geography of global change and species richness in Northern parts of the world. In this study, we examined the signals of biodiversity change caused by different anthropogenic stressors using a systematic review of previous studies published between years 2000 and 2015. The main aim was to investigate in which way, and due to which stressors, species richness in different biological groups has changed in Northern regions.
This review showed that in the majority of the study cases, anthropogenic stressors had either decreased species richness or had no effects on it. Other types of effects, such as positive or non-linear, were less common.
Two of the most commonly-studied biological groups (plants and invertebrates) showed different trends regarding species richness responses to anthropogenic stressors. Species richness of plants seemed to increase twice as often as species richness of invertebrates, which in turn decreased twice as often compared with that of plants. Overall, the results showed that Northern freshwater ecosystems may be the most sensitive ecosystem type susceptible to different anthropogenic stressors. The results showed that species richness usually decreased in fresh waters. Out of all the studied types of stressors, pollution seemed to be the most harmful stressor affecting species richness.
Overall, this systematic review showed that species richness-stressor relationships has been sparsely studied both in quantity and geographically. There are areas in the Northern regions where no investigations on human impacts on biodiversity have been done. At the same time, based on the publications we reviewed, species richness more often was affected by anthropogenic stressors than had remained unaffected. These results are alarming, as Northern latitudes are projected to face the strongest effects due to global change (IPCC 2013).
So to wrap things up, we can clearly see that there is a need for more research on human impacts on biodiversity. Please funders, be aware of this and grant money to us poor researchers. 😉
IPCC (2013) Climate Change 2013: The physical science basis. Contribution of working group I to the Fifth assessment report of the Intergovernmental panel on climate change. Cambridge, United Kingdom and New York, USA
Vilmi, A., Alahuhta, J., Hjort, J., Kärnä, O.-M., Leinonen, K., Perez Rocha, M., Tolonen, K. E., Tolonen, K., Heino, J. (2017) Geography of global change and species richness in the North. Environmental Reviews (2), 184–192. doi:10.1139/er-2016-008
World Wildlife Fund (2016) Living Planet Report 2016. Retrieved from http://wwf.panda.org/about_our_earth/all_publications/lpr_2016/