Search results for "ECOSYSTEM"
showing 10 items of 1752 documents
The effects of long-term drainage and subsequent restoration on water table level and pore water chemistry in boreal peatlands
2014
Summary Degradation by drainage threatens biodiversity and globally important peatland ecosystem functions such as long-term carbon sequestration in peat. Restoration aims at safeguarding peatland values by recovering natural hydrology. Long-term effects of drainage and subsequent restoration, especially related to within-site variation of water table level and pore water chemistry, are poorly known. We studied hydrological variation at 38 boreal Sphagnum peatland sites (pristine, drained and restored) in Finland. The average water table level was significantly lower at Drained than Pristine sites especially near the ditches. We also observed large pore water chemical differences between Dr…
Long-Term Consequences of Water Pumping on the Ecosystem Functioning of Lake Sekšu, Latvia
2020
Cultural eutrophication, the process by which pollution due to human activity speeds up natural eutrophication, is a widespread and consequential issue. Here, we present the 85-year history of a small, initially Lobelia&ndash
Cuencas de montaña y la construcción de una encuesta interdisciplinaria
2021
Este estudio presentó una reflexión sobre la encuesta como estrategia de investigación social, dentro de un contexto específico, como lo representan las cuencas de montaña. Y más aún, la problemática se enfocó en la recolección de datos que tienen que darse dentro de los sistemas de riego; por esta razón, el objetivo fue la identificación de aquellos aspectos que deben ser tomados en cuenta para la construcción de una encuesta interdisciplinaria en ese contexto. Se realizó una revisión sistemática exploratoria de literatura sobre el tema propuesto y en la región señalada. Los principales hallazgos establecieron la necesidad de que los estudios sobre estos ecosistemas, tienen que tomar en cu…
Israeli Crowdfunding: A Reflection of Its Entrepreneurial Culture
2020
AbstractCrowdfunding has its roots deep in the Israeli entrepreneurship ecosystem. Its characterizing elements of—collective individualism combined with flat social hierarchies, low degree of separation, mandatory army service that enforces innovative thinking and improvisation, Chutzpah, and finally high tolerance for failure, all provide fertile ground for entrepreneurship and facilitate innovative approaches to entrepreneurship funding such as crowdfunding. In light of this, the growth of crowdfunding in Israel is not surprising. While the equity crowdfunding leads the field, rewards and donations platforms are more known and popular, indeed the brand name of the senior rewards and donat…
Modeling the influence of alternative forest management scenarios on wood production and carbon storage: A case study in the Mediterranean region
2016
Forest ecosystems are fundamental for the terrestrial biosphere as they deliver multiple essential ecosystem services (ES). In environmental management, understanding ES distribution and interactions and assessing the economic value of forest ES represent future challenges. In this study, we developed a spatially explicit method based on a multi-scale approach (MiMoSe-Multiscale Mapping of ecosystem services) to assess the current and future potential of a given forest area to provide ES. To do this we modified and improved the InVEST model in order to adapt input data and simulations to the context of Mediterranean forest ecosystems. Specifically, we integrated a GIS-based model, scenario …
Convergence and divergence in organization of phytoplankton communities under various regimes of physical and biological control
2010
The hypothesis that physical constraints may be as important, if not more important, than biological ones in shaping the structure of phytoplankton assemblage was tested by analyzing longterm (11–29 years) phytoplankton series in eight lakes and nine sites located along a latitudinal gradient in the Northern hemisphere. Phytoplankton biomass was used and similarity of assemblages in same months of the annual data sets was then calculated by subtracting the Bray–Curtis dissimilarity index from 1. The extent of biological and physical forcing was partly based on ‘‘expert evaluation’’: the importance of four physical (light availability, temperature, conductivity, and sediment stirring up) and…
Grouping facilitates avoidance of parasites by fish
2013
Background. Parasite distribution is often highly heterogeneous, and intensity of infection depends, among other things, on how well hosts can avoid areas with a high concentration of parasites. We studied the role of fish behaviour in avoiding microhabitats with a high infection risk using Oncorhynchus mykiss and cercariae of Diplostomum pseudospathaceum as a model. Spatial distribution of parasites in experimental tanks was highly heterogeneous. We hypothesized that fish in groups are better at recognizing a parasitized area and avoiding it than solitary fish. Methods. Number of fish, either solitary or in groups of 5, was recorded in different compartments of a shuttle tank where fish co…
Large Scale Knowledge Matching with Balanced Efficiency-Effectiveness Using LSH Forest
2017
Evolving Knowledge Ecosystems were proposed to approach the Big Data challenge, following the hypothesis that knowledge evolves in a way similar to biological systems. Therefore, the inner working of the knowledge ecosystem can be spotted from natural evolution. An evolving knowledge ecosystem consists of Knowledge Organisms, which form a representation of the knowledge, and the environment in which they reside. The environment consists of contexts, which are composed of so-called knowledge tokens. These tokens are ontological fragments extracted from information tokens, in turn, which originate from the streams of information flowing into the ecosystem. In this article we investigate the u…
Predator Mixes and the Conspicuousness of Aposematic Signals
2003
Conspicuous warning signals of unprofitable prey are a defense against visually hunting predators. They work because predators learn to associate unprofitability with bright coloration and because strong signals are detectable and memorable. However, many species that can be considered defended are not very conspicuous; they have weak warning signals. This phenomenon has previously been ignored in models and experiments. In addition, there is significant within- and among-species variation among predators in their search behavior, in their visual, cognitive, and learning abilities, and in their resistance to defenses. In this article we explore the effects of variable predators on models th…
Jack of all trades, master of all: a positive association between habitat niche breadth and foraging performance in pit-building antlion larvae.
2012
Species utilizing a wide range of resources are intuitively expected to be less efficient in exploiting each resource type compared to species which have developed an optimal phenotype for utilizing only one or a few resources. We report here the results of an empirical study whose aim was to test for a negative association between habitat niche breadth and foraging performance. As a model system to address this question, we used two highly abundant species of pit-building antlions varying in their habitat niche breadth: the habitat generalist Myrmeleon hyalinus, which inhabits a variety of soil types but occurs mainly in sandy soils, and the habitat specialist Cueta lineosa, which is restr…