Vascular plants, bryophytes, and lichens
Offenhaltungsversuche des Landes Baden-Württemberg / Fallowland project of Baden-Württemberg
Land-use and agriculture are no invariants, but are changing due to various factors originating from, e.g., economy, technology, or the general public. Which amount of land is used for which specific purpose always has been subject to major fluctuations depending on many parameters. However, when many farmers (especially those with smaller farms) abandoned their land during the 1950’s, 60’s, and 70’s, large agricultural areas become fallow land. In the course of succession the vegetation on such fallow land changes, leading to an increasing proportion of tall herbs, perennials, and finally woody plants, and re-cultivation thus becomes increasingly elaborate. Against this background, the Fallowland project of Baden-Württemberg is addressing the question how agricultural grassland can be kept open using minimum (financial, personal, and technical) effort, which is done by comparing the effect of different maintenance measures at 14 sites in Baden-Württemberg. These measures are grazing (traditional management), mowing, mulching, and controlled burning (alternative managements), with undisturbed succession on separate plots used as a control. Results are evaluated regarding nature conservation and agricultural aspects, and practical recommendations are given.
Further information is given by the supervising institution, the LEL Baden-Württemberg: http://www.lel-bw.de/pb/,Lde/Startseite/Unsere+Themen/Offenhaltung+der+Landschaft
Urban vegetation
Cities are different from their surroundings – an obvious fact which has, nevertheless, countless facets when taking a closer look. Facets from various subjects such as urban development and infrastructure, resource usage and extraction, climate and weather, and many more. Regarding botanical research, cities are interesting special areas comprising very specific habitat types and niches, ranging from artificial but near-natural parks to graveled road edges, green roofs, and joints in pavements (see Priemetzhofer & Berger 2001). Furthermore, newly introduced neophytic species commonly appear first in cities due to, e.g., the intensive traffic connection. And so there is a »cocktail« of indigenous species and others which were (and are) intentionally planted or unintentionally introduced. Comparisons among cities or between cities and their surroundings thus provide new aspects regarding habitat ecology, chorology, population biology, and further research fields.
Priemetzhofer, F. & Berger, F. (2001): Flechten in Pflasterritzen – ein bemerkenswerter, mit Füßen getretener Sonderstandort. – Beitr. Naturk. Oberösterreichs 10: 355-369 [»Lichens in pavement joints – an interesting, but trampled special habitat«]
Indicator values and functional traits
Why are the giant rhubarb’s leaves that huge, while English daisies have such small ones? Why are there white, yellow, red, and blue flowers? Why do water-lilies live aquatic while mistletoes grow on trees? – Some relationships, such as wind dispersal in dandelions, are obvious also for kids. However, to understand the meaning of, e.g., pinnate leaves, funnel-shaped flowers, resinous excretions, paper-like bark, subterraneous runners, or spiny pollen grains, thorough studies of anatomical, physiological, or ecological aspects are necessary. In addition, species and plant communities can be classified and characterised using ecological indicator values like those compiled by Heinz Ellenberg and Elias Landolt; with such values, variables like temperature, nutrient content, or substrate openness can be addressed in analyses. Both, indicator values and functional traits, give information on, e.g., site conditions, bioindication, appropriate conservation measures, or endangerment analysis, and thus form an important foundation: for basic research as well as for practical applications in nature conservation, agri- and silviculture, environmental planning, and further fields.
Plant and vegetation
Just like a toy car or a knight’s castle is built using the pieces of a construction kit, the pieces of the vegetation cover surrounding us are plant species and individuals, though these don’t have explicit »plug connections«. In fact, connections are defined by the past and recent effect of ecology, human impact, geology, climate, etc. on the species and their habitats. Vegetation science must, thus, deal with two topics: first, the plant species themselves, their distribution and requirements; and second, vegetation as a whole, as it is made up from single species having specific requirements.
The first topic may be summarised as »Man liebt nur, was man kennt, und man schützt nur, was man liebt.« [»We only love those things we know well, and we only take care for those things we love.«] This motto by Konrad Lorenz seems to be a universal principle, applicable for research on species as well as for applied nature conservation. Identification books and field guides hence are essential for species knowledge in botany. What is, however, better than species knowledge »alone«? One answer may be: to get additional information on the species’ ecology and characteristics, or their role in the vegetation. But fortunately, nature is so complex that one can not simply understand it – new plant species come to Central Europe (as wanderers or introduced by man), new species are described, new insights in ecological contexts and systems are gained. Our identification books should, therefore, be improved, expanded, and amended.
In addition to this first topic the second topic is about getting to know the connections between the single pieces. Given that environmental conditions are sufficiently similar and that historical and anthropogenic impacts are comparable, similar plant communities arise and can be described as associations. Single plants and plant associations grow in specific biotopes and habitats which, again, can be defined based on the effective factors. Combining the knowledge on biotopes/habitats and species communities makes it possible to understand and describe vegetation.
Succession research allows us to witness how species communities emerge and are replaced again. Initial »settlers« arrive where – by natural processes or human impact – open soil, wounded bark, bare rock surface (… or also concrete surface!) have been created. Such early succession species will then be replaced by successors based on specific processes, sequences, species identity, and species traits, which all are the field of succession research.
