The impact of monoculture tree plantations on biodiversity in the Italian Prealps

Simone Balestra ¹, Vanessa Manuzi ¹, Erica Ceresa ¹, Pietro Gatti ¹, Reetta Pirttilahti ¹, Gianalberto Losapio ²

Università degli Studi di Milano ¹, Università degli Studi di Milano; University of Lausanne ²

Forest ecosystems cover 31% of the global land surface and are subject to a deforestation rate of 13 million ha yr^ (-1). To counteract this trend, several reforestation programs started worldwide. However, these actions raised several problems including the use of non-native species and the poor diversity levels. Furthermore, the long-term effects of reforestation on biodiversity remain poorly documented. Italian history of land management gave us the opportunity to study the long-term effects of reforestation on biodiversity as monocultures of red spruce (Picea abies) were widely planted in northern Italy during the 1920s. We studied the consequences of the spruce plantations on biodiversity of soil fauna and plants. Our focus was on the possible ecological changes triggered by spruce plantations such as soil acidification and canopy cover. We hypothesize spruce monoculture reduces biodiversity at local and regional scales given the non-native range of the spruce and the limestone substrates. We compared plant and soil fauna communities of the spruce monoculture plantations with two other native habitats, including native forests and pastures belonging to two sites in Italian Prealps (Como province). We also measured ecological parameters such as soil properties, ecological indicators, management data and environmental parameters; to extract as much environmental information as possible. We found that spruce monoculture reduces plant diversity in an indirect manner, through the change of environmental conditions such as light input and carbon recycling. We also found a potential negative effect toward arthropod diversity by spruce monoculture, despite our results are still incomplete.

Main author career stage: Master student

Contribution type: Poster

First choice session: 2. Ecology

Second choice session: 3. Biodiversity and global change