Search results for " Community"
showing 10 items of 1104 documents
Are the effects of an invasive crayfish on lake littoral macroinvertebrate communities consistent over time?
2016
Management of invasive species requires assessment of their effects on recipient ecosystems. However, impact assessment of invasive species commonly lacks a long-term perspective which can potentially lead to false conclusions. We examined the effects of the invasive signal crayfish (Pacifastacus leniusculus Dana) on the stony littoral macroinvertebrate communities of a large boreal lake and assessed the extent to which the patterns observed in previous short-term studies were stable over time. We used temporal macroinvertebrate data collected in five consecutive years from a site with a well-established crayfish population, a site with no crayfish and a site where crayfish had been recentl…
New populations of the threatened fern Equisetum moorei Newman in the Valencian Community (Spain)
2020
Se aportan nuevas citas del helecho amenazado Equisetum moorei en la Comunidad Valenciana, donde solo se conocían previamente seis localidades con presencia actual de la especie. Una de las nuevas poblaciones amplía notablemente el área de distribución conocida en esta región, ya que la mayor parte de las localidades conocidas se concentraban en el macizo del Peñagolosa (provincia de Castellón). Se describen las características ecológicas y demográficas de las nuevas localidades en el contexto de las poblaciones previamente conocidas en la región valenciana.
Active Wild Food Practices among Culturally Diverse Groups in the 21st Century across Latgale, Latvia
2021
Simple Summary A study in the bordering region of Latvia took place in order to investigate wild plant food uses. In total 72 interviewees reported food uses. The most represented uses of recorded plants were recreational tea; for jam; as snacks and soup; and drink. Interviewees also reported loss of foraging practice due to the habitat change as for example in case of caraway and chamomile. The results indicated that part of the reason for the main use of wild plants were linked to diet diversification. Abstract Local ecological knowledge (LEK), including but not limited to the use of wild food plants, plays a large role in sustainable natural resource management schemes, primarily due to …
Quantifying and addressing the prevalence and bias of study designs in the environmental and social sciences
2020
Building trust in science and evidence-based decision-making depends heavily on the credibility of studies and their findings. Researchers employ many different study designs that vary in their risk of bias to evaluate the true effect of interventions or impacts. Here, we empirically quantify, on a large scale, the prevalence of different study designs and the magnitude of bias in their estimates. Randomised designs and controlled observational designs with pre-intervention sampling were used by just 23% of intervention studies in biodiversity conservation, and 36% of intervention studies in social science. We demonstrate, through pairwise within-study comparisons across 49 environmental da…
Thirty years unmanaged green roofs: Ecological research and design implications
2016
Abstract The variations in species composition and assemblage of unmanaged simple-intensive green roofs in Hannover, Germany, were investigated over a thirty year period, in order to assess the persistence of the initial seed mixture and to evaluate floristic changes. The roofs were greened in 1985 with soil-based turf rolls sown with a mixture of five grasses (Festuca rubra, Festuca ovina, Agrostis capillaris, Lolium perenne and Poa pratensis). Three sets of 120 phytosociological releves, sampled in 1987, 1999 and 2014, have been compared to assess: (1) nestedness vs spatial turnover, (2) functional diversity and (3) the importance of vegetation dynamics on green roof performance and desig…
Defoliation effects on plant and soil properties in an experimental low arctic grassland community – the role of plant community structure
2008
In Northern Fennoscandia, sub-arctic and arctic grasslands are commonly grazed by the semi-domesticated reindeer. Reindeer grazing is known to affect plant production and belowground processes, such as nutrient mineralization in these grasslands, but little is known of the role of plant community structure in the response of plant and soil properties to the defoliation of plants. Using soil and seeds from a low arctic meadow, we established a 23-week greenhouse experiment to test whether communities of different plant species richness (one, two or four species) and composition (three different replicated compositions within each richness level) respond to defoliation in a different way. We …
Plant functional trait response to environmental drivers across European temperate forest understorey communities
2020
Functional traits respond to environmental drivers, hence evaluating trait-environment relationships across spatial environmental gradients can help to understand how multiple drivers influence plant communities. Global-change drivers such as changes in atmospheric nitrogen deposition occur worldwide, but affect community trait distributions at the local scale, where resources (e.g. light availability) and conditions (e.g. soil pH) also influence plant communities. We investigate how multiple environmental drivers affect community trait responses related to resource acquisition (plant height, specific leaf area (SLA), woodiness, and mycorrhizal status) and regeneration (seed mass, lateral s…
Can vegetation provide indications of ancient lake shorelines after more than one hundred years? A case study of Iskander-kul Lake, Tajikistan
2017
Abstract Bioindication is a common approach to assess and evaluate environmental changes over both short or long periods of time. Here we attempt to highlight that vegetation can provide indications of the palaeoshoreline of Lake Iskander-kul, even after at least 150 years. It is an example of a dammed lake that was created by a huge mass rockfall as a result of a strong earthquake during the late Pleistocene. Applying the two way indicator species analysis (TWINSPAN) we found that the shrubby vegetation is the particular one that can still effectively thrive along the palaeoshoreline despite the lake downlift. Using the phi coefficient as a fidelity measure for certain vegetation type, we …
Soil functional indicators in a mountain forest-rangeland mosaic of northern Iran
2021
Abstract Soil plays an essential role in providing ecosystem services, especially in mountain ecosystems which are often considered as fragile and sensitive systems and commonly consist of a mosaic of forest and rangeland plant communities. The relationship between above-ground plant cover and the properties of soil organic and mineral layers in mountain areas are rarely studied. This research aimed to assess the effect of different land covers (i.e. forest, forest-rangeland ecotone, and rangeland) on soil functional indicators, i.e. fertility and biological activities, in the Hyrcanian region of northern Iran. We hypothesized that (i) the presence of tree cover enhances soil fertility and …
Interpreting immunological indices: the importance of taking parasite community into account. An example in blackbirds Turdus merula.
2015
13 pages; International audience; Despite the intensive use of immune indices in immunoecology, whether to interpret the results of immune indices in terms of actual immune competence (i.e. ability to control and clear parasite infections as indicated by high values of immune indices associated with low parasite loads) or current immune activation (pathogenic infection being associated with high parasite load and high values of immune indices) is still an open question. Most studies to date have produced contrasting results focused on the effect of a single parasite species despite the fact that hosts usually harbour a community of parasites that influences one another's impact on host immu…