Research team:
Coordinator
Researcher´s:
Mgr. Jan Vondrák, Ph.D.
Lichens – indicators in fragmentated primeval forests in the Czech Republic (Activity 11)
The perspective of the Activity 11 is analysis of current quality of primeval forest ecosystem fragments in the Czech Republic based on detailed inventory of epiphytic lichens. Their biodiversity will be compared with biodiversity in planted forests growing in their vicinity. Epiphytic lichens are very well known for their usage as bioindicators of primeval forests. Many rare species occur only in primeval forests. Epiphytic lichen indicators are traditionally used for evaluation of quality of primeval forests in Europe. The main question is if planted forest can eventually evolve in ecosystems with similarly high biodiversity of epiphytic lichens.
Stage of research results:
The aim of our research was analysis of quality old-growth (primeval) forest ecosystem fragments in the Czech Republic based on detailed inventory of epiphytic lichens in preserved fragments of mountain spruce forests (Picea abies) and forests with dominance of beech (Fagus sylvatica). Old-growth forests were compared with managed spruce forests planted after disturbances and with forests developing into old-growth beech forest.
A natural and independently developing forest ecosystem (primeval forest, not plantation of the same age trees for wood production) is naturally rich with a variety of organisms. They are for each other a source of nutrition, a partner in symbiosis or simply substrate. Lichens as symbiotic organisms of macro- and microscopic size are often tiny and invisible part of such an ecosystem, mostly overgrowing trunks and branches of trees, and decaying wood. The majority of Central Europaean primeval forests were changed to managed forests with low growth heterogenity of low age due to short rotation period. Primeval forests are surviving only as dispersed fragments, often as small as 1 km2. The very high importance of these fragments was repeatly demostrated as centre of biodiversity of numerous organisms including epiphytic lichens. Lichens are known as indicators of "primevality"; many rare species occur only in primeval forests. Using lichens as indicators of primeval forests is traditional in other countries of Europe but still lacking in the Czech Republic.
During 2015 and 2016, we selected and surveyed 40 1 ha plots for epiphytic lichens. We surveyed 10 plots of each: primeval or old-growth of spruce forests, managed spruce forests, primeval beech forests, and managed beech forests developing into primeval forests. We surveyed plots in pairs, always an old-growth forest and managed forest in the closest distance each of other and with minimum diferences between them in geomorphological, climatic and ecological factors.
We used a newly developed field reseach method previously tested in food-plain forests enable to provide high quality of inventory data on biodiversity of selected areas and enable data comparison. The highest quality plots are selected subjectively. The selected plot must be situated inside of the biotop area (never at the border) in well lightened thin growth with the highest diversity of substrates. Trees of all age stages (from seedlings up to very old living trees) together with dead trees, snags and lying decaying wood should all be present in the selected plot. In such a site the local „hot-spot“ of epiphytic lichen diversity is expected. The plot is surveyed by minimum of 4 researchers acting as individuals in parallel in a competitive survey. A managed forests should be surveyed for 4 to 6 hours, an old-growth forests for 6-8 hours according to richness of species in the plot. Researchers writing down species in their field notebooks underline every half hour the list of species. The survey is finished after the most researchers did not add any new lichen species in the last half hour. This competetive method forces researchers to full intensity work and obtains maximum species. According to previous testing we found the single researcher is able to obtain maximum two thirds of real number of species in the locality even in the small area of several hectars and his effort inserted in the survey is often very low. Consequently, many species remain undiscovered.
We surveyed fourty localities in mountain areas situated along the border of the Czech Republic, mainly in protected areas; twenty spruce forests: Hrubý Jeseník Mts (Bílá Opava 1, Bílá Opava 2, Eustaška), Králický Sněžník Mts (1 locality), Šumava Mts (Boubín Mt., Smrčina Mt., Hraničník Mt.), Krkonoše Mts (Jelení brook), Beskydy Mts (Lysá hora Mt., Kněhyně Mt.) and 20 beech forests: Beskydy Mts (Razula, Salajka, Mionší), Český les Mts (Diana, Chejlava), Novohradské hory Mts (Žofín), Šumava Mts (Boubín Mt., Stožec Mt., Smrčina Mt., Hraničník Mt.).
The collected material, a total of about 4000 specimens, was studied with lab stereo- and light microscopes. Reagents for thalline spot tests such as K, C, KC and PD were used for determination of many samples. Selected specimens (ca 400) were identified by means of TLC or with molecular methods. Identified, dried and desinsected samples were prepared in herbarium specimens and labeled. Specimens are stored in institucional (PRA) and private herbaria of researchers.
With the research in primeval forests we obtainded very interesting results. With the new method of research we found in most plots of 1 ha higher number of species than known before from the pertinent nature reserve. Expectation of low species diversity in forests dominated by spruce, as a phrophyte characterized by very low ph of bark (pH 3.0-3.5) and hosting limited number of species was not confirmed. The spruce forests have high lichen epiphytic diversity. Most surveyed localities were well lightened forests (compared to beech forests) with dominance of macrolichens. Large number of species occurred on spruce wood which evidently has optimal characteristics and hosts usually significantly larger number of species than wood of many bload-leaved trees (mainly beech). The number of species was also enlarged with an additional tree occuring in spruce primeval forests (Sorbus aucuparia), characterized with diferent characteristics of bark hosting diferent communities of lichens than spruce (Picea abies). Species diversity in best localities exceeded 120, epiphytic and epixylic species of lichens.
The richest spruce plots were in Šumava Mountains situated in the south of the Czech Republic, where the impact of acid rains was not so dramatic compared with mountain ridges at the north border of the country. Surprisingly rich in lichen species was a single locality in Krkonoše Mountains, where are still surviving lichens very sensitive to air pollution, which we would never suspected in this mountain range – e.g. Alectoria sarmentosa and Evernia divaricata. The old-growth forests in the area of Praděd Mountain in Hrubý Jeseník Mountains were also rich. Surprisingly rich in number of lichen species were in the managed forests adjacent primeval forests (average 60 to 80 species in 1 ha). There was also clearly seen rare species spreading from natural to managed forests. For this reason, it is difficult to establish indicators of lichens of old growth forest that should be widely distributed in most primeval areas while lacking in economic forests. Suitable candidates should be for example Chaenotheca sphaerocephala and Lecanactis abietina.
Based on the analysis, we showed that the number of species per 1 ha of primeval spruce forests is an average of about 110 species, ranging from 80 to 145 species among plots. Stands with more than 120 species are well preserved light spruce forests with high heterogeneity of substrates from seedlings up to the old trees (300 to 400 years), dead standing trees, lying trees, snags, and rotting wood. Continuity with a rich vegetation databank of diaspores and undisturbed meso- and microclimate environment are the main factors behind high biodiversity, albeit reduced, due to the toxic effects of air pollution, especially acid rains. In contrast, managed spruce forests, and those from the surrounding area of ??primeval forests with potential for future higher diversity, are mostly monocultural forests of the same age with an average of 72 species of lichens with a minimum of 60 and maximum of 102 species. It is quite obvious that managed spruce forests richest in lichen species are below the average of biodiversity in the primeval forests.
Primeval beech and fir-beech forests were in number of species slightly richer than spruce forests. The main reason is the wide range of characteristics of beech bark, which has a smooth and acidic bark when young but later coarser and only slightly acidic bark. The old, decaying bark of beech is a substrate for many species of lichens. Slow degradation of beech wood also increases the diversity of lichens. Infected and dead beeches can due to the high pH bark host a variety of lichens tied to trees wirh subneural bark (such as elm or maple). Fir trees whose bark is acidic and allows the occurrence of only a few tolerant acidophiles were lichen species poor in most cases. Contrary, sycamore (Acer pseudoplatanus), maple (A. platanoides), and elm (Ulmus glabra) significantly increase range of substrates for lichens in natural and primeval beech forests.
We found the highest number (150) of epiphytic and epixylic lichen species in the plots in the Natural Reserve Diana in Český les (Bohemian Forest Mts), Žofín virgin forest in Novohradské hory Mountains and in the Šumava Mountains. Significantly poorer were primeval forests in Beskydy Mountains despite being well preserved. Sever acid rains and high air pollution from coal mining localities in close distance to these forests are responsible for devastating majority of macrolichens and many microlichens in this area.
The primeval beech forests hosted on an average twice the species richness of the managed forests. This is a much bigger difference in comparison to spruce forests, primarily because of the substantial shading in young beech forest, in which only a limited range of species are able to survive. Appropriate bio-indicators of primeval beech forests can be considered Lopadium disciforme, Varicellaria hemisphaerica and Thelotrema lepadinum. Differences between natural and economic forests can be also very clearly shown in the presence so-called "caliciod" lichens and fungi from genera eg. Calicium, Chaenotheca or Chaenothecopsis, which generally prefer old and dead trees or naturally stripped stumps, and therefore they are much more abundant and diverse in the primeval beech forests.
To protect forest lichens (and indeed many other groups of wild organisms) the size of reserve or size of non-intervention area is crucial. Only large forest units can sustain a diversity of substrates, for instance different types of decaying wood and plenty of old trees with specific characteristics, such as increased pH of bark due to infection of a tree or sap-exudation. It is in these microhabitats that numerous substrate specialists occur, eg. Bacidia incompta, Gyalecta flotowii and Sclerophora pallida. The primary objective of conservation should be expanding protective buffer zones of unmanaged forest around primeval forest reserves to limit the gradual extinction of different species with narrow ecological niches.
One very negative management practice is fencing reserves, which due to the absence of large herbivores causes a strong regeneration of trees, so their dense undergrowth soon overshadows tree trunks of old trees with rich diversity. In the shade only survive a few resistant species of lichens and overall diversity of vegetation decreases substantially. A positive example of management is a very light forest Diana primeval forest, on the contrary, negative management results are seen in the Boubín virgin forest with rampant forest beech renewal. The challenge for the future is to find methods that would enable efficient and rapid assessment of primeval vegetation and its potential for conservation, even without a thorough knowledge of certain groups of organisms. Of great potential is the use of bioindicative species, mainly lichens, fungi and mosses, whose monitoring we should continue to focus on. In the case of lichens, we will probably use a less obvious crustose species because sensitive macrolichens usually survive only a few locations in the country.
Use of appropriate lichen indicators is suitable for repeated monitoring of the state of valuable forest and for assessing the risks of further fragmentation of selected habitats. Selection of practices to mitigate the effects of the fragmentation from the perspective of different spatial scales (regional, nationwide) is highly desirable. For this reason detailed data to species from localities were gathered and filled in species database usable for subsequent repeated monitoring in future.
The proposed new methodology of field research, proposed management changes and database with data are outputs directed to the primary target group (government / public administration, farming entities). They will lead to the maintenance of natural associations and natural habitats of species.
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