Afforestation and biodiversity: Changes in biodiversity of birds, beetles and ground vegetation along a successional gradient in a black cottonwood (Populus trichocarpa) plantation in South Iceland

• Main Author: Gundelach, Tallulah, 1992-
• Other Authors: Háskóli Íslands
• Format: Thesis
• Language: English
• Published: 2018
• Subjects: Umhverfis- og auðlindafræði; Skógrækt; Líffræðileg fjölbreytni; Deadwood; Fugla; Iceland
• Online Access: http://hdl.handle.net/1946/31874

In Iceland, afforestation is an important element of environmental management. A 14.5 hectare managed black cottonwood (Populus trichocarpa) plantation in South Iceland serves as the country’s oldest research site for monitoring ecological changes resulting from afforestation of previously abandoned land by a non-native species. The forest was established in 1990 and monitored in 1993 and 2003 and the present study repeated the same monitoring. The aim of this study was to understand how the current growth stage of the forest has affected the population density, species composition and biodiversity of birds, beetles, and ground vegetation. Beetle- and vegetation surveys were conducted on permanent 10x10m plots during the whole growing season or during late summer 2017, respectively. The breeding density of birds was measured across previously determined forest transects in spring 2017. The forest, which had been thinned after the last monitoring, had reached middle-aged maturity, marked by high basal area, dense tree canopy that had started self-thinning, and an increase in deadwood and litter on the forest floor. Several changes regarding biodiversity had occurred. For example, higher forest density changed the composition of ground vegetation cover, including an increase in unvegetated surface and a decrease in vascular plants. The population density of beetles had not changed much from the last survey, but their species composition shifted towards higher abundance of forest specialist species. The breeding density of birds increased for species typically breeding in woodlands, such as redwings (Turdus iliacus), and a new forest bird species for Iceland, common wood pigeon (Columba palumbus), was found. Given the limited knowledge of the impacts of forestry on the flora and fauna of Iceland, this long-term project provides valuable insights for future management. [Nýskógrækt og líffræðilegur fjölbreytileiki: Breytingar á fjölbreytileika fugla, bjallna og botngróðurs við framvindu asparskógar (Populus ...