Search results for "PRI"
showing 10 items of 17196 documents
Seagrass ecosystem response to long-term high CO2 in a Mediterranean volcanic vent
2014
We examined the long-term effect of naturally acidified water on a Cymodocea nodosa meadow growing at a shallow volcanic CO2 vent in Vulcano Island (Italy). Seagrass and adjacent unvegetated habitats growing at a low pH station (pH = 7.65 ± 0.02) were compared with corresponding habitats at a control station (pH = 8.01 ± 0.01). Density and biomass showed a clear decreasing trend at the low pH station and the below- to above-ground biomass ratio was more than 10 times lower compared to the control. C content and δ13C of leaves and epiphytes were significantly lower at the low pH station. Photosynthetic activity of C. nodosa was stimulated by low pH as seen by the significant increase in Chla…
Nest sites of a strong excavator, the Great Spotted Woodpecker Dendrocopos major, in a primeval forest
2017
In managed forests, birds that create their own breeding holes in trees have limited access to substrates in which they can excavate. Therefore, nest site use in these forests possibly reflects availability of substrates more than species preferences. We analysed data on nest sites of Great Spotted Woodpeckers Dendrocopos major collected during 1987–2013 in the strictly protected part of Białowieża National Park in East Poland. The woodpeckers excavated breeding holes in 11 tree species, but species used in individual habitats varied greatly: Alder Alnus glutinosa was almost the only species used in the riverine forest; Common Aspen Populus tremula, Common Hornbeam Carpinus betulus and Pedu…
The Impact of Variations in the Climate on Seasonal Dynamics of Phytoplankton
2009
Phytoplankton, an assemblage of suspended, primarily autotrophic single cells and colonies, forms part of the base of the pelagic food chain in lakes. The responses of phytoplankton to anthropogenic pressures frequently provide the most visible indication of a long-term change in water quality. Several attributes related to the growth and composition of phytoplankton, such as their community structure, abundance as well as the frequency and the intensity of blooms, are included as indicators of water quality in the Water Framework Directive. The growth and seasonal succession of phytoplankton is regulated by a variety of external as well as internal factors (Reynolds et al., 1993; Reynolds,…
A physiology-based Earth observation model indicates stagnation in the global gross primary production during recent decades
2020
Abstract Earth observation‐based estimates of global gross primary production (GPP) are essential for understanding the response of the terrestrial biosphere to climatic change and other anthropogenic forcing. In this study, we attempt an ecosystem‐level physiological approach of estimating GPP using an asymptotic light response function (LRF) between GPP and incoming photosynthetically active radiation (PAR) that better represents the response observed at high spatiotemporal resolutions than the conventional light use efficiency approach. Modelled GPP is thereafter constrained with meteorological and hydrological variables. The variability in field‐observed GPP, net primary productivity an…
Enabling policy innovations promoting multiple ecosystem benefits: lessons learnt from case studies in the Baltic Sea Region
2019
Abstract This paper analyses how specific institutional barriers and drivers affect the success of agri-environmental governance and policy innovations in four case study catchments in Germany, Latvia, Poland and Sweden. Possible adaptations of institutional settings are explored, aiming at increased effectiveness of policies and governance in delivering multiple ecosystem benefits along with reduced nutrient emissions and flood management. Factors of success synthesized from existing examples of innovative policy instruments in the EU and further afield are used to identify barriers and opportunities for the implementation of policy innovations in different institutional settings across th…
Conservation and people: Towards an ethical code of conduct for the use of camera traps in wildlife research
2020
International audience; Abstract 1. Camera trapping is a widely employed tool in wildlife research, used to estimate animal abundances, understand animal movement, assess species richness and understand animal behaviour. In addition to images of wild animals, research cameras often record human images, inadvertently capturing behaviours ranging from innocuous actions to potentially serious crimes. 2. With the increasing use of camera traps, there is an urgent need to reflect on how researchers should deal with human images caught on cameras. On the one hand, it is important to respect the privacy of individuals caught on cameras, while, on the other hand, there is a larger public duty to re…
Assessing environmental conditions of Antarctic footpaths to support management decisions.
2016
Thousands of tourists visit certain Antarctic sites each year, generating a wide variety of environmental impacts. Scientific knowledge of human activities and their impacts can help in the effective design of management measures and impact mitigation. We present a case study from Barrientos Island in which a management measure was originally put in place with the goal of minimizing environmental impacts but resulted in new undesired impacts. Two alternative footpaths used by tourist groups were compared. Both affected extensive moss carpets that cover the middle part of the island and that are very vulnerable to trampling. The first path has been used by tourists and scientists since over …
Combined effects of fishing and oil spills on marine fish: Role of stock demographic structure for offspring overlap with oil
2018
It has been proposed that the multiple pressures of fishing and petroleum activities impact fish stocks in synergy, as fishing-induced demographic changes in a stock may lead to increased sensitivity to detrimental effects of acute oil spills. High fishing pressure may erode the demographic structure of fish stocks, lead to less diverse spawning strategies, and more concentrated distributions of offspring in space and time. Hence an oil spill may potentially hit a larger fraction of a year-class of offspring. Such a link between demographic structure and egg distribution was recently demonstrated for the Northeast Arctic stock of Atlantic cod for years 1959–1993. We here estimate that this …
Modeling of Dead Wood Potential Based on Tree Stand Data
2020
Here we present a framework for identifying areas with high dead wood potential (DWP) for conservation planning needs. The amount and quality of dead wood and dying trees are some of the most important factors for biodiversity in forests. As they are easy to recognize on site, it is widely used as a surrogate marker for ecological quality of forests. However, wall-to-wall information on dead wood is rarely available on a large scale as field data collection is expensive and local dead wood conditions change rapidly. Our method is based on the forest growth models in the Motti forest simulator, taking into account 168 combinations of tree species, site types, and vegetation zones as well as …
Drought Stress Memory at the Plant Cycle Level: A Review
2021
International audience; Plants are sessile organisms whose survival depends on their strategy to cope with dynamic, stressful conditions. It is urgent to improve the ability of crops to adapt to recurrent stresses in order to alleviate the negative impacts on their productivity. Although our knowledge of plant adaptation to drought has been extensively enhanced during the last decades, recent studies have tackled plant responses to recurrent stresses. The present review synthesizes the major findings from studies addressing plant responses to multiple drought events, and demonstrates the ability of plants to memorize drought stress. Stress memory is described as a priming effect allowing a …