ISLANDPALECO · Tracking past human impact on islands by improving palaeoecological reconstructions with PalEnDNA analysis

Tracking past human impact on islands by improving palaeoecological reconstructions with PalEnDNA analysis

Island ecosystems host a significant proportion of global biodiversity, but their rich biotas are more vulnerable to pressures than continental ones. Human colonization has been a recent event on most islands, and has nearly always resulted in losses of biodiversity. The Canary Islands were no exception; colonized by aborigines at least 2000 years ago and later by Europeans, they have been transformed since that time. Despite being one of the most biodiverse regions within Europe and a target for EU biodiversity policies, there is a knowledge gap about the pre-human state and natural variability of Canarian ecosystems. This makes the Canaries the perfect place to reconstruct baselines and the long-term impact of human activities. One of the main difficulties in the implementation of palaeoecological tools in the Canaries is to detect fossils. This is due to poor conditions for preservation at certain sites, i.e. “silent sites”, and under-representation of key taxa in the fossil record, i.e. “ghost taxa”. The analysis of ancient DNA from palaeoenvironmental samples (PalEnDNA), provides a complementary tool to traditional proxies. The main aims addressed by ISLANDPALECO are: 1) to improve the reconstruction of past environments by revealing the past occurrence of “ghost taxa” and unlocking past records from “silent sites”; 2) to assess the timing and extent of human impact on Canarian ecosystems, providing pre-human vegetation baselines, and related post-(aboriginal) and post-(European) vegetation responses; and 3) to communicate the results to scientists and managers so that palaeoecological information can be easily incorporated into ecological restoration and conservation, and disseminated to the society. PalEnDNA has been successfully retrieved from “silent sites” providing a first insight into the long-term dynamics and early human impact of lowland ecosystems in the Canary Islands. PalEnDNA from “ghost taxa” has also been detected improving the knowledge on the long-term ecology of key species for Canarian ecosystems. The results obtained are improving environmental reconstructions and are significantly valuable for managers targeting effective restoration programs. This is the first time that PalEnDNA analysis is implemented in the Canaries and probably one of the few cases on islands, being a valuable example for other island regions.

Data: CORDIS, © European Union