Panu Halme

Color Signals in the Black Grouse (Tetrao tetrix): Signal Properties and Their Condition Dependency

Recent progress in techniques of quantifying between‐individual differences of color‐based ornaments has revealed undiscovered possibilities for research in sexual selection. We present how the color spectra data can be comprehensively used for studying the importance of sexual ornaments in the black grouse and how these ornaments are related to a male condition. For this, we used both correlative field and experimental data. Field data indicated that older males had more chromatic coloration than yearlings. Blue chroma of males was correlated with male mating success. We experimentally manipulated yearling birds with testosterone implants and found that testosterone‐implanted males had impaired expression of several sexual ornaments: 10 months after the implantation, both structural‐based blue and carotenoid‐based red eye comb coloration were diminished, as well as lyre (tail) length. However, the manipulation did not affect vital traits under natural selection (wing length or body mass). Our data indicate that structural color is an important trait in sexual selection in this lekking species. Importantly, the data also indicate that male sexual ornaments are more susceptible to environmental conditions than the other male traits, thus showing their heightened condition dependency compared with the other traits mediating the honesty of signaling.

The importance of timing and number of surveys in fungal biodiversity research

Practical conservation of biological diversity is dependent on reliable knowledge about what kind, how much, and where the diversity is. To obtain such knowledge three questions, why, what, and how, must be answered before commencing any biodiversity survey. While the questions why and what are often value decisions and thus determined outside the realm of scientific research, the question about how the surveys are conducted lies in the heart of science. Here, we report an intensive repeated survey of wood-inhabiting fungi with the aim of determining the optimal timing and number of the surveys for reliable estimation of the diversity of this species group. The research focusing on the ecology of wood-inhabiting fungi has been increasing but little is known about the reliability of the methods. The variation in the estimates of diversity among surveys was high and the results varied between studied species groups. The site-scale detectability for species belonging to different groups varied from 10 to 95% depending on the survey month and the species group. We conclude that because detectability of many fungi turned out to be poor even when surveys were conducted at an optimal time, the common practice of using a single fruit body survey to estimate fungal diversity of any given area is not enough. We suggest that multiple surveys at an optimal time should be a norm in fungal diversity studies. Improper methodology results in unreliable outcomes that have potential to hamper our goal of conserving the biological diversity.

A fungal perspective on conservation biology

Hitherto fungi have rarely been considered in conservation biology, but this is changing as the field moves from addressing single species issues to an integrative ecosystem-based approach. The current emphasis on biodiversity as a provider of ecosystem services throws the spotlight on the vast diversity of fungi, their crucial roles in terrestrial ecosystems, and the benefits of considering fungi in concert with animals and plants. We reviewed the role of fungi in ecosystems and composed an overview of the current state of conservation of fungi. There are 5 areas in which fungi can be readily integrated into conservation: as providers of habitats and processes important for other organisms; as indicators of desired or undesired trends in ecosystem functioning; as indicators of habitats of conservation value; as providers of powerful links between human societies and the natural world because of their value as food, medicine, and biotechnological tools; and as sources of novel tools and approaches for conservation of megadiverse organism groups. We hope conservation professionals will value the potential of fungi, engage mycologists in their work, and appreciate the crucial role of fungi in nature.

Quantifying the Indicator Power of an Indicator Species

Biodiversity indicator species are needed for classifying biotopes and sites for conservation, and a number of methods have been developed for determining indicator species for this purpose. Nevertheless, in addition to site classification, there is sometimes a need to define an indicator species that indicates the occurrence of another species. For example, when a species of interest (target species) is difficult to detect or identify, a reliable indicator species can function as a tool that saves time and money. We derived a method that provides a quantitative measure of the indicator power (IP) of an indicator species for the target species or any species assemblage. We calculated the measure of IP from a presence-absence matrix that covered several sites. The method provided a list of indicator species, the presence of which reliably indicated the presence of another species (e.g., a threatened or rare species in a given area). The IP of the species was highest when the number of shared occurrences between the indicator species and the target species was high and, simultaneously, when the indicator species and the target species occurred separately in only a few cases. The IP was also positively influenced by the number of sites with no occurrences of either the indicator or the target species. Our method can also be used to quantify different types of species occurrence indications. We refer to these types as presence-presence, presence-absence, absence-presence, and absence-absence indications. To clarify the use of the method, we examined the situation with red-listed polypores in White-backed Woodpecker (Dendrocopos leucotos) habitats in Fennoscandia and found some suitable indicator species. Our method provides a new, objective way to evaluate the IP of an indicator species.

Flawed Meta-Analysis of Biodiversity Effects of Forest Management

It appears that the negative effect of forest managementon biodiversity has become an axiom. Whether the neg-ative effect, however, is a fact based on solid empiricalevidence is not self-evident. Most of the studies that ad-dress the issue suffer from a lack of geographic extentand taxonomic narrowness. Therefore, a synthesis draw-ing together results from the individual studies is direlyneeded. In their recent paper, Paillet et al. (2010) rise tothis challenge and present a formal pan-European meta-analysis of data from 49 papers representing 120 indi-vidual comparisons across 10 taxonomic groups. Theirsynthesis has the potential to be a landmark paper inecological research, but also to affect pan-European for-est policies and conservation prioritizations. In any meta-analysis, selection of studies to be included is critical forthe conclusions to be reliable, but in such a potentiallyhigh-profile contribution as the synthesis by Paillet et al.,a particularly high level of scrutiny of the data is calledfor. Here we draw attention to four major shortcomingsin Paillet et al. that undermine the conclusions of theirmeta-analysis.

Community Turnover of Wood-Inhabiting Fungi across Hierarchical Spatial Scales

For efficient use of conservation resources it is important to determine how species diversity changes across spatial scales. In many poorly known species groups little is known about at which spatial scales the conservation efforts should be focused. Here we examined how the community turnover of wood-inhabiting fungi is realised at three hierarchical levels, and how much of community variation is explained by variation in resource composition and spatial proximity. The hierarchical study design consisted of management type (fixed factor), forest site (random factor, nested within management type) and study plots (randomly placed plots within each study site). To examine how species richness varied across the three hierarchical scales, randomized species accumulation curves and additive partitioning of species richness were applied. To analyse variation in wood-inhabiting species and dead wood composition at each scale, linear and Permanova modelling approaches were used. Wood-inhabiting fungal communities were dominated by rare and infrequent species. The similarity of fungal communities was higher within sites and within management categories than among sites or between the two management categories, and it decreased with increasing distance among the sampling plots and with decreasing similarity of dead wood resources. However, only a small part of community variation could be explained by these factors. The species present in managed forests were in a large extent a subset of those species present in natural forests. Our results suggest that in particular the protection of rare species requires a large total area. As managed forests have only little additional value complementing the diversity of natural forests, the conservation of natural forests is the key to ecologically effective conservation. As the dissimilarity of fungal communities increases with distance, the conserved natural forest sites should be broadly distributed in space, yet the individual conserved areas should be large enough to ensure local persistence.

Why taxonomists and ecologists are not, but should be, carpooling?

Abstract Traditionally, ecologists and taxonomists have conducted mostly separated research. Ecologists have been using the well-known species groups as their model organisms for practical reasons, whereas taxonomists have focused on poorly known species groups. Extensive collaboration between these research fields has unfortunately been a rarity. We argue that increased collaboration between ecologists and taxonomists yields benefits through several pathways. Firstly, it improves the scientific quality of both disciplines through deeper insight on the study organisms and increased feasibility of the collected data. Secondly, it improves the prospects of the scientists involved and opens up potential funding sources, helping to solve the taxonomic impediment. Finally, improved collaboration could balance ecological research towards more species-rich, functionally important groups. This would increase the quality and effectiveness of nature conservation and management plans positively affecting the sustainability of environmental policy making. These obvious benefits should be swiftly acknowledged by research institutions, science leaders and funding bodies. They should actively promote for strong collaborative efforts from the present and recruited staff representing both disciplines.

High within- and between-trunk variation in the nematoceran (Diptera) community and its physical environment in decaying aspen trunks

Dead wood is a primary habitat for a large number of insects, including species from many nematoceran (Diptera) groups. The species living in dead wood must be adapted to the ephemeral and ever‐changing nature of their substrate. There is a growing body of knowledge about the effects of dead wood quality and the surrounding landscape on the saproxylic beetle community, but we know very little about the other saproxylic insects. Moreover, we know only very little about the variation in the insect community between different parts of decaying wood pieces. Using emergence traps, we studied the saproxylic nematoceran communities occupying different parts of decaying fallen aspen trunks in a boreal forest. To explain the variation in the detected assemblages, we also studied the variation in the physical environment in different parts of one of the studied trunks during the season. We found out that the overall variation in assemblages was very high and also the similarity between the base and top of the same trunk was usually low. Dissimilarity arose more from differences in species richness than from species turnover. The greatest contrasts in the physical conditions of the study trunk were between the inside and the upper and lower surface of the trunk base. Due to high variation within the trunks and especially between the trunks, the sampling effort in studies on the ecology of saproxylic insects should be high to have a reliable estimate of the local community.

Do Breeding Ural Owls Strix uralensis Protect Ground Nests of Birds?: An Experiment Using Dummy Nests

Predatory birds were formerly suggested to have only negative effects on the breeding success of other birds that breed in the vicinity of their nests. However, the predator may also protect these breeding birds by chasing away other nest predators whilst either defending its own nest or by eating other predators in its territory. Ural owl Strix uralensis is known to be an aggressive nest defender. Although its diet mainly consists of voles, it also preys upon bird species (e.g. Corvidae) and even weasels Mustela nivalis, particularly when the vole densities are low. We carried out a dummy nest experiment on six Ural owl territories in central Finland to study whether Ural owls affect the nest predation rates of ground nesting birds. We found that although dummy nest predation differed between Ural owl territories, in every territory the predation risk was lowest in close proximity to Ural owl nests. The protecting effect of the predator continued for a distance of up to several hundred metres from its nest; a much further distance than could be expected if the effect was due solely to the defence of its own nest. Consequently, as suggested for other predatory birds, it may be that breeding Ural owls influence the bird community both directly by predating upon some species and/or indirectly by providing protection for other species. However, natural evidence on breeding habitat selection and predation risk of ground nesting birds should be obtained before detailed inferences on the effects of Ural owl nests on bird community levels are made.

Bryophyte Species Richness on Retention Aspens Recovers in Time but Community Structure Does Not

Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer ‘lifeboats’ to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L.) retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 ‘retention aspens’ on 14 differently aged retention sites with 102 ‘conservation aspens’ on 14 differently aged conservation sites. We used a Bayesian community-level modelling approach to estimate the changes in bryophyte species richness, abundance (area covered) and community structure during 30 years after logging. Using the fitted model, we estimated that two years after logging both species richness and abundance of bryophytes declined, but during the following 20–30 years both recovered to the level of conservation aspens. However, logging-induced changes in bryophyte community structure did not fully recover over the same time period. Liverwort species showed some or low potential to benefit from lifeboating and high potential to re-colonise as time since logging increases. Most moss species responded similarly, but two cushion-forming mosses benefited from the logging disturbance while several weft- or mat-forming mosses declined and did not re-colonise in 20–30 years. We conclude that retention trees do not function as equally effective lifeboats for all bryophyte species but are successful in providing suitable habitats for many species in the long-term. To be most effective, retention cuts should be located adjacent to conservation sites, which may function as sources of re-colonisation and support the populations of species that require old-growth forests.