Medicinal Plants in Semi-Natural Grasslands: Impact of Management

Background: Semi-natural grasslands as valuable ecosystems are significant for their high biodiversity, cultural importance and landscape values. Quantitative information about medicinal plants in semi-natural grasslands facilitates the evaluation of ecosystem services of these plant communities. Methods: Different literature sources and floristic inventory databases were used to assess the ratio and frequency of medicinal plant species in several Estonian grassland types and the impact of management on these values assessed both in Estonian and Japanese case studies. Lists of medicinal plant species according to different definition scenarios is included as Supplementary Material. Principal Component Analysis was applied for environmental preferences of medicinal plant species compared to other vascular plant species in the semi-natural grasslands.Results: The ratio of medicinal plant species in local total plant species list was the largest in alvars, followed by floodplain and wooded meadows. The average number of medicinal plant species per study plot in wooded meadows and alvars was about twice that found in naturally growing broadleaved forest (according to the most detailed MP species list 7.2, 7.8 and 4.3, respectively). Fertilization of Estonian wooded meadows had no significant impact on medicinal plant species ratio, but decreased the proportion of medicinal plant biomass in total yield. Estonian coastal meadows had a short list of medicinal plant species and the impact of management quality depended therefore on adopted definition scenario. In Japanese Miscanthus sinensis grassland case mowing or burning+mowing combination should be preferred to favor medicinal plant species number. Principal Component Analysis revealed that MP species are more drought-tolerant, common and anthropophyte than the rest of studied grassland species.Conclusions: Alternative usage of herbaceous plant species from semi-natural grasslands is a promising option to achieve sustainable development goals and increase public awareness. Further close cooperation of ecologists, economists and pharmacists is required to guarantee fair and sustainable trade of this ecosystem service in the future.

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 conditions and host tree properties affect the occurrence, abundance and fertility of the endangered lichenLobaria pulmonariain wooded meadows of Estonia

We assessed multiple environmental factors that might influence the population vitality of the epiphytic lichenLobaria pulmonariaat the individual tree and habitat levels in partially overgrown wooded meadows in Estonia. A total of 301 trees of four species were sampled at nine study plots, using a stratified factorial scheme, 151 colonized byL. pulmonariaand 150 not colonized byL. pulmonariaforming the control group. We used the Generalized Linear Models (GLZ) to identify a complex of factors which predicts the probability of the lichen occurring on tree trunks and the presence of apothecia on its individuals. We employed the General Linear Mixed Model (GLMM) to study the relationship between cover ofL. pulmonariaand environmental factors. The occurrence probability ofL. pulmonariaon tree trunks increased with increasing light availability and height of deciduous shrubs near the trunk, and decreased with increasing distance to the nearest colonized tree. The host tree species and its trunk properties were also of importance, particularly the facilitating effect of the cover of bryophytes uponL. pulmonaria. The probability of occurrence of apothecia increased with maximum values of bark pH and cover ofL. pulmonariaon the trunk. We conclude that partially overgrown wooded meadows are suitable habitats forL. pulmonaria. However, to maintain the vitality of these populations, a specific management scheme, preventing development of a dense stand, should be applied. Management requirements would include 1) selective cutting of overgrowing coniferous trees (particularly spruce), 2) preservation of adult and younger potential host trees within 10–20 m of colonized trees, 3) preservation of scattered deciduous shrubs in the vicinity of the host trees.

Changes in stand structure due to the cessation of traditional land use in wooded meadows impoverish epiphytic lichen communities

Wooded meadows with a history of traditional land use over thousands of years support a great diversity of various taxa. Today, however, high-species-rich communities in wooded meadows are threatened because of the cessation of traditional management in large areas. We studied lichen communities on 136 deciduous trees (Betulaspp.,Fraxinus excelsiorandQuercus robur) in 12 wooded meadows in three regions of Estonia, and assessed the effect of habitat change due to the abandonment of traditional management on epiphytic lichen species composition, considering factors on three spatial scales: regional, habitat and individual tree. The variation partitioning approach in partial Canonical Correspondence Analysis (pCCA) revealed that most of the variation in species composition is described by the species of host tree and tree bark pH. Other tree level variables, foremost tree diameter, described as much of the compositional variation as geographic location (region) or environmental conditions in wooded meadows. Of the environmental factors studied, woodland canopy cover is the strongest predictor of the change in epiphytic lichen species composition from the community type of semi-open wooded meadows to species-poor communities characteristic of secondary forest. General Linear Model (GLM) analysis of the abundance of the 35 most frequently observed lichen species revealed that more than half of them (21) are influenced by site openness (canopy cover and/or undergrowth density), showing that increasing canopy cover has a negative effect on the abundance of epiphytic lichen species characteristic of traditionally managed semi-open wooded meadows. The results emphasize that the preservation of large old deciduous trees of various species and the maintenance of the semi-open structure of stands are vitally important for the protection of epiphytic lichen communities in wooded meadows.

Threatened forest lichen Lobaria pulmonaria - its past, present and future in Estonia

Threatened forest lichenLobaria pulmonaria- its past, present and future in EstoniaLobaria pulmonariais a conspicuous and widely known epiphytic lichen species which mainly occurs on mature hardwood trees in old forests. The distribution ofL. pulmonariahas become highly fragmented, showing a decline across Europe.Lobaria pulmonariais unevenly distributed among ca. 600 localities in Estonia. Most localities are in north-eastern and south-western Estonia (50% and 21% of records respectively). 86% ofL. pulmonarialocalities are in nature reserves, national parks or woodland key habitats (WKH). In 81% of historical localities known until 1992,L. pulmonariacould be considered extinct. 6% ofL. pulmonarialocalities have become destroyed in the period from 1993 to 2010 due to clear cutting; in 19% of localities the species could be considered endangered, as its neighbourhood is affected by forest management activities. 40% of destroyed localities are located in forests designated as WKHs in north-eastern Estonia, and most of the endangered populations are also within WKHs. In forest management and conservation planning, WKHs should be preserved with surrounding buffer areas in order to avoid abrupt changes in environmental condition and natural disturbance regimes. There is also a necessity to develop specific management methods to recover reforested wooded meadows, to ensure that species of semi-open habitats are retained, e.g. by reducing the density of spruce.

Wooded meadows of Estonia: conservation efforts for agricultural landscape

We provide an overview of the amount and ecological condition of wooded meadows throughout Estonia after significant changes in agriculture in the second part of 20th century. We also present the first attempt to estimate the success of recent conservation efforts for wooded meadows. Our analysis is based on recent exhaustive inventories. We found that Estonia, despite a decrease of the area in wooded meadows by two orders of magnitude during the 20th century, still has about 8400 ha remaining of which approximately 5800 ha are meadows with, at the least, an intermediate conservation value. The latter is directly dependent on mowing regime. Efforts to preserve wooded meadows include establishment of protected areas and financial support for mowing. The national conservation subsidy has been useful and supportive for wooded meadows, however the total amount of this subsidy has been small compared to the area that could be supported. The much larger funds of agri-environmental subsidies have largely not been available for wooded meadows. Moreover, there has been no record keeping about subsidisation of semi-natural grasslands using agricultural support schemes. Although the preservation of some good examples of wooded meadows in Estonia seems guaranteed, further degradation of this valuable habitat type on a national scale is very probable.;