The history and future of fungi as biodiversity surrogates in forests

An overview of reviews of conservation flagships: evaluating fundraising ability and surrogate power

The main role of flagship species in biodiversity conservation is to raise awareness and funds for conservation. Because of their marketing role, flagship species are often selected based on other than biodiversity related criteria, such as species charisma or aesthetic appeal. Nonetheless, funds raised through flagship species are often used to protect the species itself, making it important to evaluate the effectiveness of flagship species as conservation tools: For example, could superior fundraising ability outweigh the low biodiversity surrogate power of a flagship, justifying this ambivalent role in conservation? To assess flagship effectiveness from this dual perspective, we must synthesize evidence on a) the fundraising potential of flagship species vs. other conservation targets, such as ecosystems or biodiversity, and b) the biodiversity surrogate power of potential flagship taxa. We approached this broad topic through an overview of reviews on both subtopics. We found no evidence that charismatic flagship species were superior fundraisers over other conservation targets. In addition, studies evaluating the biodiversity surrogacy power of different taxa had mainly resulted in mixed findings, contesting the overall usefulness of the concept in conservation. The variability of study setups and methods made comparisons between studies difficult, highlighting the need to standardize future research (e.g., standardizing explanatory variables). Further possible reasons for lack of conclusive evidence on fundraising potential are the dominance of factors other than flagship identity (e.g., scope and conservation status) and differences in donor preferences. We recommend Environmental NGOs to develop and diversify their fundraising strategies based on best available knowledge, and rely less on mere species charisma.

Polypore fungi as a flagship group to indicate changes in biodiversity - a test case from Estonia

Polyporous fungi, a morphologically delineated group of Agaricomycetes (Basidiomycota), are considered well studied in Europe and used as model group in ecological studies and for conservation. Such broad interest, including widespread sampling and DNA based taxonomic revisions, is rapidly transforming our basic understanding of polypore diversity and natural history. We integrated over 40,000 historical and modern records of polypores in Estonia (hemiboreal Europe), revealing 227 species, and including Polyporus submelanopus and P. ulleungus as novelties for Europe. Taxonomic and conservation problems were distinguished for 13 unresolved subgroups. The estimated species pool exceeds 260 species in Estonia, including at least 20 likely undescribed species (here documented as distinct DNA lineages related to accepted species in, e.g., Ceriporia, Coltricia, Physisporinus, Sidera and Sistotrema). Four broad ecological patterns are described: (1) polypore assemblage organization in natural forests follows major soil and tree-composition gradients; (2) landscape-scale polypore diversity homogenizes due to draining of peatland forests and reduction of nemoral broad-leaved trees (wooded meadows and parks buffer the latter); (3) species having parasitic or brown-rot life-strategies are more substrate-specific; and (4) assemblage differences among woody substrates reveal habitat management priorities. Our update reveals extensive overlap of polypore biota throughout North Europe. We estimate that in Estonia, the biota experienced ca. 3-5% species turnover during the twentieth century, but exotic species remain rare and have not attained key functions in natural ecosystems. We encourage new regional syntheses on long studied fungal groups to obtain landscape-scale understanding of species pools, and for elaborating fungal indicators for biodiversity assessments.

Habitat Models of Focal Species Can Link Ecology and Decision-Making in Sustainable Forest Management

A fundamental problem of sustainability is how to reduce the double complexity of ecological and social systems into simple operational terms. We highlight that the conservation concept of focal species (selected species sensitive to a set of anthropogenic threats to their habitat) links multiple issues of ecological sustainability, and their habitat models can provide a practical tool for solving these issues. A review of the literature shows that most spatial modeling of focal species focuses on vertebrates, lacks the aspect of aquatic and soil habitats, and has been slow in the uptake by actual management planning. We elaborate on a deductive modeling approach that first generalizes the main influential dimensions of habitat change (threats), which are then parameterized as habitat quality estimates for focal species. If built on theoretical understanding and properly scaled, the maps produced with such models can cost-effectively describe the dynamics of ecological qualities across forest landscapes, help set conservation priorities, and reflect on management plans and practices. The models also serve as ecological hypotheses on biodiversity and landscape function. We illustrate this approach based on recent additions to the forest reserve network in Estonia, which addressed the insufficient protection of productive forest types. For this purpose, mostly former production forests that may require restoration were set aside. We distinguished seven major habitat dimensions and their representative taxa in these forests and depicted each dimension as a practical stand-scale decision tree of habitat quality. The model outcomes implied that popular stand-structural targets of active forest restoration would recover passively in reasonable time in these areas, while a critically degraded condition (loss of old trees of characteristic species) required management beyond reserve borders. Another hidden issue revealed was that only a few stands of consistently low habitat quality concentrated in the landscape to allow cost-efficient restoration planning. We conclude that useful habitat models for sustainable forest management have to balance single-species realism with stakeholder expectations of meaningful targets and scales. Addressing such social aspects through the focal species concept could accelerate the adoption of biodiversity distribution modeling in forestry.