FUNCTIONALBIO

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FUNCTIONALBIO

Functional biodiversity in forests: diversity of soil decomposers and predatory and parasitic arthropods

DOWNLOAD 2009 REPORT AS PDF (pdf 407Kb)
DOWNLOAD 2009 REPORT IN IRISH (pdf 395Kb)

PROJECT TEAM
Prof. Thomas Bolger, University College Dublin*
Joan Kenn, University College Dublin
Dr Tom Harrington, University of Limerick
Richard O'Hanlon, University of Limerick
Dr Julio Arroyo, University College Dublin
Dr Annette Anderson, University College Dublin
Dr Aidan Keith, University College Dublin

* Email: tom.bolger@ucd.ie

COMPLETION DATE: September 2010

BACKGROUND
In forests, growth and decomposition are the two most important ecosystem functions. Plants supply the majority of growth within the ecosystem, while fungi and soil fauna are the main drivers of decomposition. A large amount of research has been carried out on forest plants, therefore this project is designed to study the biodiversity associated with the other important functional aspects of forest ecosystems. The taxa selected were: fungi, soil microarthropods, parasitoid wasps, bugs and nematodes. Mycorrhizal fungi are important within forest ecosystems as they form associations with the roots of many tree species and assist in the assimilation of nutrients. Soil arthropods play a major role in decomposition and nutrient cycling and also help inoculate roots with mycorrhizae. Within the forest system, there is far greater biodiversity below-ground than above-ground, for example there are approximately 1,000 species of soil invertebrates in a single square metre of beech forest.
Apart from soil fauna, some groups of above-ground arthropods are being studied. Ecological theory suggests that arthropod communities with more complex food web structures and high numbers of predatory and parasitic species have greater inherent population stability and are less prone to pest outbreak. Parasitic hymenoptera were studied as a representative above-ground group.

OBJECTIVES

Compile a literature review of previously conducted biodiversity studies that relate to this work.
Select forest sites in Ireland where field sampling will be conducted in collaboration with groups from UCC and TCD.
Compile a macrofungal basidiomycete and ascomycete inventory of selected woodland sites encompassing the functional groups: ectomycorrhizal fungi, saprotrophs, pathogenic wood-decay fungi.
Obtain information on the abundance of fruiting bodies of edible forest fungi in the selected woodland sites.
Relate fungal diversity to site and management factors such as native/non-native broadleaf versus plantation conifer canopy, conifer/broadleaf mixtures, second rotation versus first rotation plantation, stand age, soil type, herb layer vegetation.
Relate the efficiency of fungal biodiversity indicators to other biodiversity indicators in Irish forests.
Assess additional aspects of biodiversity (Hemiptera, parasitic Hymenoptera, nematodes and soil microarthropods) in forests that have not been covered by the BioForest project (2001-2006).
Assess the below-ground biodiversity of forests in detail.
Provide inventories of the biodiversity in the habitats studied.
Develop methodologies to assess biodiversity in forests.
Draw up recommendations to enhance biodiversity in plantation forests.

PROGRESS
Lists of mite species recorded from forests have been compiled and reviews of the Collembola, Hemiptera, parasitic Hymenoptera and nematodes are ongoing and being placed in the context of the fauna recorded from other Irish habitats, in particular agricultural grassland, peatland and some coastal habitats. The analysis for the mites is virtually complete and shows that, in Ireland, many species have been exclusively recorded in forests, in particular in habitats such as fungal fruiting bodies. Thus we can conclude that forests add considerably to the biodiversity of mites in the Irish landscape. This work is ongoing and databases are updated as new data become available.

Macrofungal basidiomycete and ascomycete inventory. The third of the three planned annual samplings was completed in November 2009. During the 2009 autumn period, 28 sites were sampled compared with 26 in 2008. The total number of site visits in 2009 was 83, compared with 55 in 2008. Over the course of three years the project has sampled 910 quadrats covering approximately 18,200 m2 of forest.
Data acquired from field sampling include a quantitative assessment of each macro fungal found in a site including substrate data.
Site variables were also collected. These include:
Soil nutrient data measured using the new PRS technology.
Deadwood quality and volume has been assessed.
Soil samples have been collected and are being analysed for N, P, K, Ca, Mg, pH, moisture content and carbon content.
Data on the physical canopy structure of each site have been collected .
Data on canopy cover has been collected using the canopy scope method.
A full list of vegetation present at each site has been compiled.

Ectomycorrhizal (EM) fungi. Fifteen sites have so far been sampled (primarily Sitka spruce) by soil coring. A preliminary screening based on morphological criteria has separated EM samples into recognisable types. Samples of all types have been retained in glutaraldehyde for morphological assessment, and at -80ºC for identification by molecular methods. Abundance of different types on tree roots has been scored. Work has commenced on molecular identification.
Significant outcomes to date. In total, 478 fungal species have been identified from fruit bodies taken from the sites. There were 125 new species realised in 2009 compared with 108 new species in 2008 and 247 new species in 2007. Preliminary analysis of the fungal species found that 178 were listed as common on the British checklist of fungi www.basidiochecklist.info/index.htm .

Five forest types were sampled: first and second rotation Sitka spruce, Scots pine, ash and oak. A representative of each of these types was selected in each of five geographical areas of the country.
A very large diversity of mites and Collembola has been recovered in studies where sampling was carried out by climbing trees. The assemblages in the soil and in moss on the tree are different from the assemblages on the bare branches which are made up of a relatively small number of species; however, these species tend to be specific to such bare branch habitats while the many similar species occur in moss on trees and in soil. The species occurring on the broadleaved species (oak and ask) are different to those occurring on conifers. Virtually no differences were detected between first and second rotation Sitka spruce. The sites sampled were blocked into different regions which were seen to differ significantly from one another. In particular the assemblages found in the Clare/Galway/Tipperary, Cork/Kerry and Wicklow/Kildare area were fairly distinct, while those from Laois/Offaly and Sligo/Roscommon were intermediary in structure.
Approximately, 270 genera of parasitic wasps have been identified from the five forest types sampled. Each forest type appears to have a unique fauna, with only 18 genera common to all forest types. The broadleaf forests, ash and oak, show the greatest diversity with approximately 180 and 170 genera respectively. Comparatively lower parasitoid diversity was found in the coniferous forests with Scots pine, first rotation and second rotation Sitka spruce forests with 85, 65 and 67 genera respectively. Much of the diversity of the ash forests can be attributed to one site: St John's Wood in Roscommon. To date, only half of the specimens from this site have been identified, but 126 genera have been determined. The ichneumonid, Pantisarthrus luridus (Foester), was recorded for the first time in Ireland from an ash site at Donadea Forest Park (Kildare). Many specimens have been sent to the Natural History Museum, London, for verification and it is likely that at least some of these will be new Irish records.

ACTIVITIES PLANNED
Continue to add to species databases.
Critical fungal identification will sent to experts for verification.
The assessment of ectomycorrhizal diversity on roots of each site will be completed in early in 2010 using mophotyping and molecular methods
Quantitative analysis of macrofungal diversity data will be completed.
The relationship between fungal diversity and other biodiversity metrics on the forest sites will be evaluated.
Completion of the identification of the specimens collected. This will now involve collaboration with international experts to ensure proper identification of 'difficult' species.
Analysis and publication of data.

OUTPUTS
A visiting scholar exchange post was taken at Oregon State University from May 2009 to mid July 2009. A poster was presented on the project at the North American forest ecology workshop NAFEW2009 in Logan Utah in June 2009 www.nafew2009.org.
A presentation on the project entitled Fungal Diversity in Irish Forest Ecosystems was given by Richard O'Hanlon at the seminar Forest Fungi in Ireland at Avondale House, Co Wicklow on 28 August 2009.

2008 report

download 2008 report as pdf (pdf 200Kb)

PROJECT TEAM
Prof. Thomas Bolger, University College Dublin*
Dr Julio Arroyo, University College Dublin
Dr Annette Anderson, University College Dublin
Dr Aidan Keith, University College Dublin
Dr Alvin Helden, University College Dublin
Joan Kenny, University College Dublin
Dr Tom Harrington, University of Limerick
Richard Hanlon, University of Limerick

* Email: tom.bolger@ucd.ie

COMPLETION DATE: December 2009

BACKGROUND
In forests, growth and decomposition are the two most important ecosystem functions. Plants supply the majority of growth within the ecosystem, while fungi and soil fauna are the main drivers of decomposition. Soil arthropods play a major role in decomposition and nutrient cycling within forests, and also help inoculate roots with mycorrhizae. Mycorrhizae are important within forest ecosystems as the associations they form with the roots of many tree species assist in the assimilation of nutrients. Within the forest system, there is far greater biodiversity below-ground than above-ground, for example there are approximately 1000 species of soil invertebrates in a single square metre of a beech forest. Also the biodiversity of macrofauna are of considerable importance in soil systems.
The taxa selected for study (fungi, soil microarthropods, parasitoid wasps, bugs (Hemiptera), and nematodes) were chosen specifically because of their potential usefulness as indicators in forest systems, and because they are additional taxa that significantly broaden the ecological scope of the assessment of biodiversity in Irish forests.

OBJECTIVES
The objectives of this research project are to:
assess the biodiversity of mites, Collembola, bugs and parasitic wasps in canopies;
assess the below ground animal biodiversity;
compile an inventory of macrofungal basidiomycetes and ascomycetes;
assess abundance of fruiting bodies of edible forest fungi;
relate diversity to forest type;
relate the efficiency of fungal biodiversity indicators to other biodiversity indicators in Irish forests;
develop methodologies to assess biodiversity in forests;
draw up recommendations to enhance biodiversity in plantation forests.

PROGRESS
Canopy sampling by tree climbing trees is now complete and has yielded a large number of species.
The samples processed thus far have yielded three species new to science. These come from the genus Zercon. The descriptions have been accepted for publication and will appear in early 2009. These findings are of a great ecological and faunistic importance because Zercon species are not commonly found in arboreal habitats, suggesting a sharp distinction between arboreal and soil species.
The genus Licneremaeus (Acari: Oribatida) has been recorded for first time in Ireland and Scanning Electron Microscopy (SEM) was used to confirm the identifications of Xenylla brevicauda, and its presence in Ireland which has been disputed. Discussions with taxonomists are ongoing.
A literature review of the Acari and Collembola species found in Irish forests is ongoing. This will be the basis for the biodiversity inventory.
Four study sites were fogged in August 2007. Three study sites were fogged in August and September 2008. The remaining 18 study sites will be fogged in summer 2009 and completed by end July 2009.
Soil cores were collected in 2007 and 2008 and a number have been processed for mite and collembolan species. A subset has been processed for nematodes.
From a total of 3,544 fruit bodies counted 354 species of fungi have been identified. The data from two year's sampling indicate that:
the mycoflora differ between stands of different type. Ash sites were found to a very different and impoverished assemblage of macrofungi compared to that of the other tree species;
oak sites had the most diverse macrofungal assemblages on average, but more species were found on Sitka spruce sites. This may be due to more Sitka spruce sites being investigated.

ACTIVITIES PLANNED
Activities planned for 2009 include nematode fieldwork, fogging fieldwork, and laboratory work for samples. Literature review for all Acari and Collembola species found in research projects and theses is ongoing. Verification of species identities in difficult groups will be necessary.
Analysis of mycorrhizal populations in forest sites will be analysed and the PCR protocol will be refined. The remaining site variables will be collected, such as vegetation data, photosynthetic active radiation (PAR), and the soils of each site will be classified according to their physical and chemical attributes.
Another sampling for fungi will take place in summer and autumn 2009.
OUTPUTS
Moraza, M.L., Arroyo, J. and Bolger, T. 2008. Three new species of mites (Acari: Zerconidae) from canopy habitats in Irish forests. Zootaxa (in press).
Arroyo, J. and Bolger, T. An overview at the Oribatid mite fauna (Arachnida, Acari) inhabiting the canopy of a young Sitka spruce plantation in Ireland. Environ 2008 Dundalk IT.
A commentary on the project appeared in Science Spin (Issue 23).