Georg A. Janauer

Managing protected areas under climate change: challenges and priorities.

The implementation of adaptation actions in local conservation management is a new and complex task with multiple facets, influenced by factors differing from site to site. A transdisciplinary perspective is therefore required to identify and implement effective solutions. To address this, the International Conference on Managing Protected Areas under Climate Change brought together international scientists, conservation managers, and decision-makers to discuss current experiences with local adaptation of conservation management. This paper summarizes the main issues for implementing adaptation that emerged from the conference. These include a series of conclusions and recommendations on monitoring, sensitivity assessment, current and future management practices, and legal and policy aspects. A range of spatial and temporal scales must be considered in the implementation of climate-adapted management. The adaptation process must be area-specific and consider the ecosystem and the social and economic conditions within and beyond protected area boundaries. However, a strategic overview is also needed: management at each site should be informed by conservation priorities and likely impacts of climate change at regional or even wider scales. Acting across these levels will be a long and continuous process, requiring coordination with actors outside the “traditional” conservation sector. To achieve this, a range of research, communication, and policy/legal actions is required. We identify a series of important actions that need to be taken at different scales to enable managers of protected sites to adapt successfully to a changing climate.

The measurement of current velocities in macrophyte beds

Abstract The modification of a propeller-type flowmeter to measure current velocities within beds of submersed macrophytes in an improved way is presented. The instrument permits readings in a small cross-section of 0.05 m diameter, within short spatial distances, and without disturbing the internal structure of the plant stand. Investigation of different plant species showed this method to be sufficiently accurate to describe the transition zone between the plant stand and the unvegetated section of streams and channels.

Macrophytes, hydrology, and aquatic ecotones: a GIS-supported ecological survey

Abstract The detection of macrophyte-dependent ecotones, the characterization of different hydrological regimes and aspects of sports fishing activities were the main objectives studied in a backwater system of the River Danube in Austria. The macrophyte survey, a dynamic hydrological model and a socio-economic study were all part of the Austrian Ecotone Project. Conclusions were drawn from this database by GIS thematic map interpretation and overlay techniques. Significant transitions existed between stretches of macrophyte vegetation as far as species number and plant mass are concerned. These transitions can be attributed as macrophyte-dependent aquatic/aquatic ecotones. Some plant species and the structural diversity of the aquatic vegetation were found to be characteristic for backwater reaches with different hydrological regimes. In contrast to a hypothesis worked out earlier in the ecotone project the GIS overlays revealed spatial coincidence between the centres of sports fishing activities and survey stretches with high densities of macrophyte vegetation.

Macrophytes and Flood Plain Water Dynamics in the River Danube Ecotone Research Region (Austria)

In the ecotone research region of the Danube in Austria (Man-and-the-Biosphere (MaB)- project 5/21, Austrian Academy of Science) the macrophytes are one of the most important groups of organisms investigated. The species composition and the plant mass in hydrologically dynamic, and in predominantly stagnant sections of a system of lateral branches and sloughs were studied. This study showed that areas protected from frequent disturbance by floods had a greater number of species and higher biomass of aquatic macrophytes. Some species were shown to be evenly distributed throughout the branch system, whereas other species tended to form rare, but large singular patches. A set of new data elaboration techniques enabled us to describe the distribution pattern of the aquatic vegetation in this large branch system of the River Danube.

The distribution of organic and mineral components in leaves and stems of Ranunculus fluitans Lam.

The differences in chemical composition of leaves and stems of Ranunculus fluitans Lam. were investigated. Typical distribution of organic and inorganic compounds were generally found not to be influenced by factors as day-time, eutrophication, or age of the weed bed. Starch, sugars, amino acids, and organic acids were at a higher level in the stem, but inorganic cations and anions were accumulated in the leaf. The distribution pattern and the relative contents of individual sugars, acids, and inorganic ions are discussed in detail.

Elodea canadensis and its dormant apices: An investigation of organic and mineral constituents

Abstract Some organic and inorganic constituents of Elodea canadensis Michx. and its dormant apices were investigated. Plants collected at a site with a higher phosphate load (0.14 meq PO4 l−1 daily mean, 0.28 meq l−1 maximum) were characterized by lower starch levels and higher total concentrations of cations, inorganic and organic anions, respectively, as compared with plants from a less eutrophic site. In winter, starch was accumulated in the plants and the concentrations of ionic components decreased markedly. The uniqueness of the dormant apices was demonstrated by very high starch levels and low concentrations of cations, and organic and inorganic anions. Moreover, succinate, a component not present in detectable amounts in the parent plants, made up 3.7% of the total organic anion content.

Ecohydrological control of macrophytes in floodplain lakes

Floodplain lakes are one of the most essential habitats for aquatic macrophytes in the modern cultural landscape. Their maintenance and support calls for ecohydrological strategies, as river development, enhanced flood control and other stakeholder interests may have negative impact on the present oxbow ecosystems. Three examples are given to present the situation of macrophytes in floodplain water bodies on the Danube, and the Tisza River. The importance of ecohydrology as a sustainable strategy and a look back to its sources in the Ecotone MaB program are presented. Finally conclusions point to regionalisation of planning goals as the solution for many aspects in floodplain water management.

Typha control efficiency of a weed-cutting boat in the Lac de Guiers in Senegal: a preliminary study on mowing speed and re-growth capacity

Prolific growth of Typha australis in the lower part of the Senegal River and the Lac de Guiers resulted from changed ecological conditions following the construction of two high dams in the Senegal River. Fluctuation of the water level has decreased markedly and the water has changed from brackish to fresh as the inflow of salt water from the ocean is prevented. The efficiency of a hydraulic weed cutting boat (model Conver 480 H) has been tested in various plots in the Lac de Guiers. This lake, connected with the Senegal River, is economically very important as it is the city of Dakars major drinking water supply and also provides irrigation water for vast agricultural areas. Cutting, performed at 20 cm and 50 cm below the water surface, was very effective in removing Typha stands. However, due to the excessively thick stems of the Typha plants, cutting took much more time compared to similar operations in Europe. It was estimated that approximately 35 h were required to clear one ha of dense Typhastands. Directly after cutting re-growth was observed during a relatively brief period (approximately three months), however, subsequently all newly formed growth tips in the plots had suddenly disappeared. It was concluded that this sudden collapse was linked to a destruction of the root zone due to anoxic conditions. Eventual re-growth was relatively slow as after one year the plots were still largely free from Typha plants. Efficiency of mowing was not related significantly to depth of cutting.

The effects of emersion on soluble carbohydrate accumulations in Hippuris vulgaris L.

Abstract The influence of emersion on carbohydrate accumulation in Hippuris vulgaris L. was studied by comparing the carbohydrate levels of fully submersed plants with those of plants producing emergent shoots. In all plant fractions, the dominant component was stachyose. It reached levels up to 34.6% dry matter. In both growth forms the green submersed parts contained between 2.12 (submersed plants) and 2.41 (plants with emergent apices) times more soluble carbohydrate, respectively, than the corresponding basal white parts. Another pool of carbohydrates was located in the emergent parts: the carbohydrate level of plants with emergent apical sections was about 8 times that of submersed plants. Emergent plants stored about 7 times more carbohydrate in the green submersed parts and 6.2 times more in the basal white parts than fully submersed plants. Thus the effects of direct access to atmospheric sources of CO 2 , and the lack of any attenuation of irradiance by backscattering or absorbance in the water, achieved by aerial stems, are clearly evident in the different carbohydrate contents of submersed and emergent Hippuris plants.

Synergies and Conflicts Between Water Framework Directive and Natura 2000: Legal Requirements, Technical Guidance and Experiences from Practice

The EU water framework directive (WFD) is intensively connected with other European legal regulations and supporting documents. This close interrelationship calls for deeper considerations when WFD is implemented in locations of high conservation value, e.g. Natura 2000 sites. A comprehensive, but specific comparison of the goals of WFD with the aims of habitats directive (HD) and birds directive (BD) provides a sensitive overview on their peculiarities, with an outlook on potential synergies and conflicts. The sometimes complex guidance for solving complicated situations in the practical application of these differing legal provisions is also described. The representation of requirements for Natura 2000 sites as part of river basin management plans, and related up-to-date experience are given special attention. Finally recommendations and conclusions provide the reader with a complete view of this challenging chapter in European Policy. In the end, considerably more synergies than conflicts are identified between the objectives of WFD, HD and BD. Whenever conflicts should arise these directives prevent derogating from their requirements by cross-references. Therefore, firm and timely coordination between water and nature conservation authorities is necessary.