Inhabiting Fungi in Boreal Broadleaved Forests

The role of novel forest ecosystems in the conservation of wood-inhabiting fungi in boreal broadleaved forests Katja Juutilainen1, Mikko Monkk€ onen€ 1, Heikki Kotiranta2 & Panu Halme1,3 1Department of Biological and Environmental Sciences, University of Jyvaskyla, PO Box 35, FI-40014 Jyvaskyla, Finland 2Biodiversity Unit, Finnish Environment Institute, PO Box 140, FI-00251 Helsinki, Finland 3Jyvaskyla University Museum, University of Jyvaskyla, PO Box 35, FI-40014 Jyvaskyla, Finland Keywords Abstract Afforested fields, corticioids, deadwood, fungal communities, natural herb-rich forests, The increasing human impact on the earth’s biosphere is inflicting changes at novel ecosystems, wood pastures. all spatial scales. As well as deterioration and fragmentation of natural biological systems, these changes also led to other, unprecedented effects and emer- Correspondence gence of novel habitats. In boreal zone, intensive forest management has Katja Juutilainen, Department of Biological negatively impacted a multitude of deadwood-associated species. This is and Environmental Sciences, University of especially alarming given the important role wood-inhabiting fungi have in the Jyvaskyla, PO Box 35, FI-40014, Jyvaskyla, natural decay processes. In the boreal zone, natural broad-leaved-dominated, Finland. Tel: +358 50 4686036; herb-rich forests are threatened habitats which have high wood-inhabiting fun- Fax: +358 (0)14 617 239; gal species richness. Fungal diversity in other broadleaved forest habitat types is E-mail: katja.m.juutilainen@jyu.fi poorly known. Traditional wood pastures and man-made afforested fields are novel habitats that could potentially be important for wood-inhabiting fungi. Funding Information This study compares species richness and fungal community composition across € € Suomen Akatemia (‘275329’) Jyvaskylan the aforementioned habitat types, based on data collected for wood-inhabiting Yliopisto, Ymparist€ oministeri€ o€ (Finnish Ministry of Environment). fungi occupying all deadwood diameter fractions. Corticioid and polyporoid fungi were surveyed from 67 130 deadwood particles in four natural herb-rich Received: 6 July 2016; Revised: 18 July 2016; forests, four birch-dominated wood pastures, and four birch-dominated affor- Accepted: 19 July 2016 ested field sites in central Finland. As predicted, natural herb-rich forests were the most species-rich habitat. However, afforested fields also had considerably Ecology and Evolution 2016; 6(19): 6943– higher overall species richness than wood pastures. Many rare or rarely col- 6954 lected species were detected in each forest type. Finally, fungal community composition showed some divergence not only among the different habitat types, doi: 10.1002/ece3.2384 but also among deadwood diameter fractions. Synthesis and applications: In order to maintain biodiversity at both local and regional scales, conserving threatened natural habitat types and managing traditional landscapes is essen- tial. Man-made secondary woody habitats could provide the necessary resources and serve as surrogate habitats for many broadleaved deadwood-associated species, and thus complement the existing conservation network of natural forests. Introduction 2013; Truitt et al. 2015). The management of these novel ecosystems should aim to maintain genetic and species The biosphere of the earth is becoming increasingly trans- diversity, and to promote healthy ecosystem function and formed by human actions (Ellis and Ramankutty 2008). services (Seastedt et al. 2008; Navarro and Pereira 2012). Changes in ecosystems include the loss of biodiversity, At the landscape level, human interference manifests as the invasion of nonnative species, altered natural distur- loss, deterioration, and fragmentation of natural habitat bance dynamics, and biotic homogenization. As a conse- types. In the boreal zone, the forest habitats have under- quence, human impact has resulted in the development gone the most radical changes: Previously continuous of biological systems that differ in species composition or canopy cover has turned into separate forest patches sur- ecological function from historical and present systems – rounded by continuously extending urban and agricul- the so-called novel ecosystems (Hobbs et al. 2006, 2009, tural areas. Additionally, intensive forest management has ª 2016 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. 6943 This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Novel Forest Ecosystems in Conservation of Fungi K. Juutilainen et al. considerably reduced both the amount and quality of has generated some unique characteristics. Due to con- deadwood in the forested landscape, jeopardizing count- tinuous fertilization, the soil of afforested fields resem- less deadwood-dependent organisms (Siitonen 2001). bles the naturally fertile soil of herb-rich forests. The Wood-inhabiting fungi can be considered the most canopy layer, however, is usually a monoculture of a important deadwood-associated species group, being certain tree species, while the understory vegetation can greatly responsible for the decay processes (Boddy et al. have idiosyncratic assemblies depending on the site char- 2008; Stokland et al. 2012). Earlier research on wood- acteristics, the preceding agricultural history, and macro- inhabiting fungi has mainly focused on the effects of for- climate (Wall and Hytonen€ 2005). The importance of est management and on species associated with large-dia- afforested fields for biodiversity is poorly known (Bre- meter deadwood (i.e., coarse woody debris (CWD)) mer and Farley 2010; Carson et al. 2010; Skłodowski (Junninen and Komonen 2011). Nonetheless, it has been 2014). To our knowledge, in the boreal zone, only shown that many wood-inhabiting fungi (also) utilize Komonen et al. (2015, 2016) have studied biodiversity in smaller deadwood particles (i.e., [very] fine woody afforested fields. Their results indicate that afforested debris ([V]FWD)) (Kruys and Jonsson 1999; Heilmann- fields host diverse ground-inhabiting fungi as well as Clausen and Christensen 2004; Norden et al. 2004; Kuef- insect communities. However, the potential importance fer et al. 2008; Juutilainen et al. 2011; Abrego and Salcedo of afforested fields for wood-inhabiting biota remains 2013). It has also been shown that each deadwood diame- unknown. ter fraction in coniferous forests hosts a partly unique, The objective of this study was to compare saproxylic partially overlapping, fungal assembly (Juutilainen et al. fungi among three woody habitat types: (1) natural herb- 2014). rich forests, (2) wood pastures, and (3) afforested fields. As the boreal forest region is dominated by coniferous Natural herb-rich forests are known to host diverse com- forests, broadleaved forests are less common and limited munities of wood-inhabiting fungi and of many other in size. Due to their naturally fertile soil, large areas of taxa. However, saproxylic fungal diversity associated with natural herb-rich forests had been widely converted into small-diameter deadwood in natural herb-rich forests is agricultural land already in the past. Thus, very few natu- still poorly known. Additionally, to our knowledge, no ral herb-rich forest stands remain today, and most of systematic research on wood-inhabiting fungi has been them are small in size. Nowadays, they are recognized as conducted in wood pastures or afforested fields. Thus, threatened habitat types and are often protected. Natural even the very basic information on the identity and ecol- herb-rich forests are known to be species-rich habitats ogy of saproxylic fungi occurring in these two habitat for wood-inhabiting fungi, as well as for many other types is lacking. This study aimed to answer the following taxonomical groups (Tonteri et al. 2008). questions: (1) Do the wood-inhabiting fungal species In addition to natural herb-rich sites, there are several richness and community composition vary across the (partly) man-made forest types which are dominated by three woody habitat types? (2) Do natural herb-rich for- broadleaved trees due to different reasons. On the one ests, wood pastures, and afforested fields host special and hand, wood pastures are seminatural, often broadleaved- noteworthy wood-inhabiting fungal species, especially on dominated woody habitats, which have been created for, FWD? (3) Can these novel habitats serve as surrogate and are maintained by, animal grazing. The semiopen, habitats for broadleaved associated saproxylic fungal sparse canopy layer of wood pastures allows more sun- species? shine to reach the forest floor than a closed forest cover. As a consequence, temperature of the ground layer and of Material and Methods the soil is higher. Moreover, animal grazing inflicts mechanical disturbance on the vegetation and the soil, Study area while urine and dung deposits create local nutrient enrichment (Bergmeier et al. 2010). Wood pastures with The study was conducted in central Finland, in the south a long grazing history have diverse vascular plant (Pyk€al€a and middle boreal vegetation zone (Ahti et al. 1968). Nat- 2003; Poyry€ et al. 2006) and ground fungi (Mustola ural herb-rich forests consist of a variable assembly of 2012) communities. Due to the intensification of agricul- broadleaved tree species (see H€amet-Ahti et al. 1998, for ture and the abandonment of traditional land

Load more