Memoranda136 Soc. Fauna Flora FennicaKomonen 93: 136–139.& Övermark 2017 • Memoranda Soc. Fauna FloraISSN Fennica0373-6873 93, (print) 2017 Helsinki 15 December 2017 ISSN 1796-9816 (online)

Ground-dwelling true bugs () in afforested fields

Atte Komonen & Elsi Övermark

Komonen, A., Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014, University of Jyväskylä, Finland. E-mail: [email protected] Övermark, E. Väliaitankatu 6 F 45, 40320 Jyväskylä, Finland. E-mail: [email protected]

Former agricultural lands may host peculiar biota, because agriculture activities have changed the physical, chemical and biological features of the soil; however, biodiversity in afforested fields is poorly known. The aim of this study was to investigate the diversity of ground-dwelling true bugs (Heteroptera) in early successional afforested fields in central Finland. We used a large-scale field experiment, in which agricultural land had been afforested 25 years ago by planting monocultures of birch, pine and spruce trees. Pitfall traps caught a total of 224 heteropteran individuals repre- senting 20 species. The community was numerically dominated by Lygaeidae, Drymus brunneus being the most abundant species. Birch plots hosted about the double the number of individu- als and species in spruce and pine plots. The near-threatened Teloleuca pellucens (Saldidae) was recorded from a birch plot. Although T. pellucens is suggested to require old-growth forests, our observation indicates that the species can occur also in other types of forests. In conclusion, more studies on Heteroptera in different environments are needed to better understand their distribution, abundance and habitat affinities.

Introduction ures (Cramer & Hobbs 2007). Agricultural activi- ties, such as fertilization, have long lasting effects Agricultural lands are afforested for varying pur- on soil and vegetation, because they increase the poses, such as to produce timber, fight erosion, amount of organic matter, pH and nutrients (Wall improve water quality, sequester carbon or sup- & Hytönen 2005). port biodiversity (Navarro & Pereira 2012). In Heterotrophic species follow changes in veg- Finland, almost 300,000 hectares have been af- etation. Vegetation composition and structure af- forested since 1970 (Finnish…2014). Given the fect via changes in microclimate, light, lit- large area of afforested fields in many regions, ter quality and litter quantity, which in turn are they can contribute to local and regional biodi- influenced by the identity of the dominant tree versity. However, little is known about biodiver- species, age structure of trees and canopy cov- sity in afforested fields in the boreal zone (but see er (Niemelä et al. 1996, Antvogel & Bonn 2001, Wall 1998, Lindgren 2000, Komonen et al. 2015, Jukes et al. 2001). Many of the heteropterans are 2016). Biological features of afforested fields de- dependent on specific plant species (Rintala & pend on the agricultural history, time since cul- Rinne 2010), so it can be expected that differenc- tivation ceased, physical and chemical quali- es in vegetation composition and structure affect ties of the soil, climate, regional species pools, their occurrence and abundance (Frank & Kün- as well as restoration and management meas- zle 2006, Zurbrügg & Frank 2006, Sobek et al. Memoranda Soc. Fauna Flora Fennica 93, 2017 • Komonen & Övermark 137

2009). Ground-dwelling heteropterans, howev- Each study site had been originally divided er, are mostly seed-eaters, fungivores, detrivores, in rectangular plots, the average plot size being predators, or they suck juices from mosses and roughly 1000 m2 (min = 225, max = 2000 m2). lichens (Rintala & Rinne 2010); thus, their re- After soil preparation, one to three-year-old seed- sponses to changes in higher vegetation are hard- lings (2000–3000 ha-1) had been planted. At eac