The mutual dependence of extensive land-use and conservation management has become apparent in Europe in the last 20-30 yr. Extensive land-use often survives in protected areas only, in the form of conservation management. Knowledge of extensive herding and that of conservation management are parts of two knowledge systems (traditional and scientific) which often leads to conflicts between locals and conservationists. We studied two herding/conservation systems (salt steppes and wood-pastures), and developed an inventory on the common/similar and conflicting/different objectives and pasture management practices of herders and conservationists. Data were collected by participatory knowledge co-production in teamwork of the co-authors (herders, conservation managers, and scientists). Data were analyzed and discussed in teamwork too. Herders and conservationists identified 23 objectives and 29 management practices. We found a number of common interests with respect to herding, the ideal state of pastures, legal provisions, and communication. Conflict resolution recommendations (e.g., on time and place of grazing, pasture improvements) were also developed. We argue that by co-production of knowledge, and establishment of a herder "school" the mitigation of the existing conflicts would be more effective. Our conclusion is that a new profession is needed: that of the conservation herder. The conservation herder shall be an individual knowledgeable about herding and pasture management, trained in conservation and ecology, able to design management experiments, and develop novel but tradition-based management practices. As such, he/she could facilitate adaptation of extensive herding in the changing socio-economic environment.

Physiological responses of two duckweed species, Lemna gibba and Lemna minor, to hexavalent chromium [Cr (VI)] were studied in axenic cultures using short-term (48 h) treatments by K 2 Cr 2 O 7 (0-200 μM). Chlorophyll (Chl) fluorescence parameters and photosynthetic pigment composition of plants were screened to determine the effects of Cr(VI) exposures. The two duckweed species exhibited different sensitivity in the applied Cr(VI) concentration range. Chl fluorescence parameters of dark-adapted and light-adapted plants and electron transport inducibility were more sensitive to Cr(VI) in L. minor than in L. gibba. We also found fundamental differences in quantum yield of regulated, Y(NPQ), and nonregulated, Y(NO), non-photochemical quenching between the two species. As Cr(VI) concentration increased in the growth medium, L. minor responded with considerable increase of Y(NPQ) with a parallel significant increase of Y(NO). By contrast, in L. gibba only 200 μM Cr(VI) in the growth medium resulted in elevation of Y(NPQ) while Y(NO) remained more or less constant within the regarding Cr(VI) concentration range during 48 h. Photosynthetic pigment content did not change considerably during the short-term Cr(VI) treatment but decrease of Chl a/b and increase of Car/Chl ratios were observed in good accordance with the changes in Chl fluorescence parameters. The data suggest that various duckweed species respond with different sensitivity to the same ambient concentrations of Cr(VI) in the growth medium, and presumably to other environmental stresses too, which may have an influence on their competitive relations when heavy metal pollution occurs in aquatic ecosystem.

Facing contrasting light regimes during a vegetation season and depending on canopy position, physiological plasticity of leaves is vital for tree species to sustain the optimal ratio between the benefit of carbon assimilation and the costs of photoprotection in a given leaf. We tested the seasonal adjustment of sun and shade leaf photochemistry of sessile oak (Quercus petraea (Matt.) Liebl.) to changing light environments by parallel investigation of the meteorological conditions, photosynthetic pigment content, PSII quantum efficiency and excitation energy quenching. Sun and shade leaves got adapted to their prevailing light regimes till mid of May. High LMA was a favourable trait in avoiding water loss and decreasing photoinhibition in both flushing and sun leaves, while low LMA optimized the light absorbing leaf surface in the lower canopy layer. Partitioning of excitation energy dissipation pathyways that is PSII photochemistry-Y(II), regulated-Y(NPQ) and non-regulated-Y(NO) quenching changed significantly during leaf ontogeny and with the position of leaves in the canopy. At 800 μmol m(-2) s(-1)Y(II) < Y (NO) < Y (NPQ) was characteristic to early developmental stage of leaves from both canopy layers and to mature shade leaves, and Y(NO) < Y (II) < Y (NPQ) to mature sun leaves but the magnitude of Y(NPQ) and violaxanthin cycle activity differed in different canopy positions.

A pásztoroló legeltetés és a természetvédelem egymásra utaltsága egyre nyilvánvalóbb. A pásztorok jól ismerik a körülöttük lévő élővilágot, az évszázados gyökerekkel bíró pásztortudományt őseiktől, szüleiktől, valamint saját tapasztalataik útján tanulták. Pásztorként hét pásztort kérdeztem a legelőhöz, legeltetéshez kapcsolódó tudásukról, elsősorban homoki, löszös és szikes területeken legeltető pásztorokat. Az eredmények jól mutatják, hogy a pásztorok gyakran otthonuknak tekintik a természetet, a legeltetés szakaszolásával, egyes területek kímélésével, megfelelő napszaki és évszaki beosztással olyan módon tudják irányítani, befolyásolni a legeltetés menetét, hogy közben hosszú távon megőrzik, esetenként fokozzák a legelőterületeik termőképességét. Hatékonyan tudják regenerálni az elavarosodott, elnádasodott területeket is. E legelőkezeléseknek nagy szerepe van a biodiverzitás megőrzésében is. Azon természetvédelmi szakembereknek és kutatóknak szól írásunk, akik szeretnék jobban megismerni, hogy a hagyományos ökológiai tudással rendelkező pásztoroknak mi lehet a szerepe a "működő" természet fenntartásában. Ahogy egy pásztor fogalmazta: az élővilágnak is van egy körforgása, amihez szükségeltetik a jószág.

In this study sap flow dynamics of mature sessile oak trees (Quercus petraea) in a marginal sessile oak-turkey oak forest was investigated in 2009. That year spring was dry without significant rain in April and May and the driest month was August. Due to the extreme weather conditions the volumetric soil water content (SWC) of upper 30 cm was low on experimental days in May (0.13-0.14 cm3 cm-3) but it reached the lowest value in August (0.08 cm3 cm-3). Sap flow was measured in a dominant and a co-dominant tree by heat dissipation method from 26 March till 30 October. In the present paper several three-day long periods of the continuous seasonal recordings were chosen to represent the effects of typical weather conditions and different stages of canopy development on sap flow dynamics. The daily maximum sap flow density values of dominant and co-dominant trees were similar (0.30-0.32 cm3 cm-2 min-1) in moist period (July). Rains and transient increase of SWC after proceeding drought resulted in change of diurnal course of sap flow in experimental days of July. In this period dominant trees also showed considerable sap flow (0.19 cm3 cm-2 min-1) during night hours and short sap flow peaks in early morning (6:00 to 8:00 a.m.) indicating the refilling of desiccated tissues. After the progressive drought in August the daily maximum sap flow density decreased to 0.07 cm3 cm-2 min-1 in dominant tree and to 0.12 cm3 cm-2 min-1 in the co-dominant. Both trees exhibited gradual stomatal closure from morning hours.