|Monitoring lučních bezobratlých v Krkonošském národním parku: současný stav a perspektivy|
|Monitoring of meadow invertebrates in the Krkonoše Mts National Park: present state and outlook|
|Pavel Marhoul; Oldřich Čížek|
Luční společenstva pod hranicí lesa tvoří velmi významnou součást Krkonošského národního parku. Přes
jejich umělý původ s historií trvající pouze několik stovek let se jedná o cenná stanoviště s druhově bohatou faunou
bezobratlých a se zastoupením vzácných a zoogeografi cky význačných taxonů. Informace o aktuálním složení
společenstev lučních bezobratlých jsou ale útržkovité a nedostatečné. Nejistoty panují také ve vztahu reakce entomofauny
na probíhající vegetační změny na loukách a na uplatňovaný management. Příspěvek přináší návrh systému
sběru dat o bezobratlých v Krkonoších, který umožní získání informací nezbytných pro rutinní činnost Správy
KRNAP při péči o louky, a současně důkladné dlouhodobé hodnocení změn ve složení společenstev a početnosti
vybraných biodindikačně významných skupin bezobratlých.
Meadow communities below the forest line constitute a very important component of the Krkonoše Mts
National Park (the Krkonoše Mts / the Giant Mts). Despite their man-made origin with a history of only a few hundred
years, they are valuable habitats with a species-rich invertebrate fauna and representation of rare and zoogeographically
significant taxa. However, information about the current composition of the meadow invertebrate communities
are fragmentary and insufficient. There are also uncertainties in relation to the response of entomofauna
to ongoing vegetation change in the meadows and the applied management regimes. This paper proposes a design
for a system of data collection on invertebrates in the Krkonoše Mts that will make it possible to obtain information
necessary for the routine meadow management and enable a thorough long-term assessment of changes in community
composition and quantities of selected invertebrate groups important as bioindicators.
|Meadow enclaves of the Krkonoše Mts National Park (KRNAP) below the forest line are secondary forestless areas, man-made since the Middle Ages, which have, despite their artifi cial origin, become habitats for numerous plant species originally bound to primary forestless areas of avalanche paths. However, in spite of long-term research in Krkonoše, the entomological importance of the meadow enclaves is still little known. Collected data are so far mere fragments, which cannot be combined to form a unifi ed picture of the secondary forestless areas due to differing methodologies and approaches. The situation is complicated by abandonment of the traditional management of meadow habitats, which has led to a degradation of vegetation in most of the meadow enclaves or their parts. Taxa monitored in more detail (notably diurnal butterfl ies and orthoptera) document significant changes in these invertebrate communities with the complete disappearance or significant reduction in the numbers of biotope specialists brought about by changing enclave management. The restoration of fl owering meadows in these Krkonoše enclaves, those planned and already launched by the KRNAP Administration, requires the establishment of an invertebrate monitoring system to enable credible assessment of the impacts of management and vegetation changes on the invertebrate communities. The establishment of an invertebrate monitoring system for the KRNAP meadow enclaves is complicated by numerous geographic (considerable total area of meadow habitats, altitude range of the enclaves, their size, isolation, orientation to cardinal points), biological (vegetation variability in enclaves) and managerial (unstable and diverse management) factors that influence the composition of the invertebrate communities. Another complication is the insuffi cient knowledge of the recent composition of the invertebrate communities in the enclaves, which makes it impossible to target specific management on the enclaves. Recent wide-ranging data obtained from the Krkonoše Mts are only available for diurnal butterflies (ČÍŽEK et al., 2015) and selected invertebrate groups obtained from 29 enclaves as part of the LIFE CORCONTICA project. With respect to the above, the paper proposes a modular system of data collection and evaluation|
based on four approaches differing in their targeting and the complexity of their components: (i) A simple system for a quick approximate assessment of the quality of meadow habitats in terms of invertebrates based on the monitoring of several selected indicator species. The selected taxa have to meet the following requirements: easy detection in the field, easy determination, strong relation to vegetation/biotope quality/structure, and time of presence and activity shared with other indicator species. The aim of the approach is to obtain operative data enabling a quick assessment of the quality of the meadow stand in question and, most importantly, identification of sites extremely endangered by inappropriate management. If the basic methodological requirements (monitoring in the same place, in comparable phases of the growing season, in analogous ways) are adhered to, this system can also be used for the long-term monitoring of selected meadows or their parts.
(ii) Expansion of the basic knowledge of invertebrate communities in the way arranged under the LIFE CORCONTICA project with more enclaves so that they cover all the important gradients of the Krkonoše Mts (altitude, northwest-southeast gradient). The outcomes would make it possible to describe the overall state of meadow fauna in selected Krkonoše meadows. (iii) Aerial mapping of selected taxonomic groups. Two groups are proposed: diurnal and nocturnal butterflies. In the case of diurnal butterflies, repeated mapping done after an appropriate time would enable a large-scale comparison of development in butterfly populations and indicate population trends of both the different species and this umbrella group as a whole. Detailed monitoring of nocturnal butterflies would help eliminate the main methodological shortcoming of the diurnal butterflies, which is their low species diversity in the KRNAP. The species diversity of the nocturnal butterfl ies is an order of magnitude greater. Information obtained by monitoring this group will permit a more detailed analysis of management effects on the species diversity and quantity of the group monitored than is the case with biurnal butterflies. (iv) The proposed approach most diffi cult to organise is repetition of the inventorying of selected invertebrate groups made under the LIFE CORCONTICA project and ideally expanded with more meadow enclaves as per (ii) above after an appropriate time. The results would permit a highly detailed comparison of changes in the invertebrate communities that will occur over the time between the surveys due to management approaches, vegetation state and vegetation changes.