Search results for "Ecosystem"
showing 10 items of 1752 documents
Growth and defense in deciduous trees and shrubs under UV-B
2005
Abstract Reflection by waxy or resinous surface structures and hairs, repair reactions of biomolecules and induction of different sheltering components provide the means of plant protection from harmful solar UV-B radiation. Secondary products, especially flavonoids and phenolic acids as defense components are also important in plant tolerance to UV-B, fulfilling the dual role as screens that reduce UV-B penetration in plant tissues, and as antioxidants protecting from damage by reactive oxidant species. Plants are sensitive to UV-B radiation, and this sensitivity can be even more clone-specific than species-specific. The results available in the literature for deciduous trees and shrubs in…
Does the freshwater mussel Anodonta anatina remove the fish pathogen Flavobacterium columnare from water?
2021
AbstractGlobal decline of freshwater mussels (Unionoida) is threatening biodiversity and the essential ecosystem services that mussels provide. As filter-feeding organisms, freshwater mussels remove phytoplankton and suspended particles from the water. By filtering bacteria, freshwater mussels also decrease pathogen loads in the water. The objective of this study was to evaluate whether the common freshwater bivalve Anodonta anatina (duck mussel) could remove the bacterial fish pathogen Flavobacterium columnare from the water. Mussels reduced bacteria in both of the two experiments performed, so that the bacterial concentration at the end of the 96-h monitoring in mussel treatments was only…
Interbasin Water Transfers in Spain: Interregional Conflicts and Governance Responses
2014
Semiarid and drought-prone Spain has managed to meet ever-increasing water demands for more than 50 years through the construction of publicly funded hydraulic infrastructure. Interbasin water transfers are the most expensive and complex supply-side tool used. They are also the most controversial, often associated with such unintended consequences as deteriorating freshwater ecosystems, disappearing recreational opportunities provided by aquatic ecosystems, and the loss of development opportunities for downstream communities. This situation has become increasingly unstable over the past decade due to the scarcity of new supply augmentation alternatives, political changes involving European …
Monthly Hydrological Indicators to Assess Possible Alterations on Rivers’ Flow Regime
2018
Assessing potential deviations of the fundamental river basins’ hydrological processes and streamflow characteristics from the “natural trajectory” represents a high-priority objective to understand the biological impact of altered flow regime on river ecosystems. Existing approaches are mainly based on the analysis of daily-based indicators of hydrologic alteration, which requires wide database, including “pre-impact” and “post-impact” daily flow data frequently unavailable. The hydrological modeling is commonly used to face data missing problems or reconstruct natural conditions, even if models, especially at the daily scales, are often complex and computationally intensive. The use of si…
A Plant Sociological Procedure for the Ecological Design and Enhancement of Urban Green Infrastructure
2021
AbstractUrban green infrastructure could represent an important mean for environmental mitigation, if designed according to the principles of restoration ecology. Moreover, if suitably executed, managed and sized, they may be assimilated to meta-populations of natural habitats, deserving to be included in the biodiversity monitoring networks. In this chapter, we combined automatised and expert opinion-based procedures in order to select the vascular plant assemblages to populate different microhabitats (differing in terms of light and moisture) co-occurring on an existing green roof in Zurich (Switzerland). Our results lead to identify three main plant species groups, which prove to be the …
Benefits of Urban Green Space for Improving Urban Climate
2007
Urban settlements transform the natural environment so greatly that people tend to see the city only as an employment site, and economic and cultural center. Thus a growing number of people prefer to reside in greener suburbs or rural areas. This results in increased automobile commuter traffic, accompanied by traffic jams, accidents, stress, and ever more damage to the environment. Concepts of sustainable development or the ecological city represent strategies for changing these negative trends. The purpose for doing so is principally the well-being of a city’s residents. Often this entails bringing more of the natural environment back into the city, because urban green space fulfills seve…
Harmonizing circumpolar monitoring of Arctic fox: benefits, opportunities, challenges and recommendations.
2017
Source at http://dx.doi.org/10.1080/17518369.2017.1319602 The biodiversity working group of the Arctic Council has developed pan-Arctic biodiversity monitoring plans to improve our ability to detect, understand and report on long-term change in Arctic biodiversity. The Arctic fox (Vulpes lagopus) was identified as a target of future monitoring because of its circumpolar distribution, ecological importance and reliance on Arctic ecosystems. We provide the first exhaustive survey of contemporary Arctic fox monitoring programmes, describing 34 projects located in eight countries. Monitored populations covered equally the four climate zones of the species’ distribution, and there were large dif…
Regional determinants of access to entrepreneurial finance: a conceptualisation and empirical study in Norwegian startup ecosystems
2022
This paper presents hypotheses and a novel examination of the influence of a set of conditional factors concerning regional industries, startup culture, ecosystem collaboration and non-financial investor resources on perceived access to startup finance. We conducted a survey of 131 nascent, early-phase or mature startups and founders associated with entrepreneurial ecosystems in rural and urban Norway. The data were analyzed using structural equation modeling. Two main findings are that (1) startups that open up for outside involvement at an earlier phase experience better perceived access to finance and (2) unrelated ventures in homogenous industrial regions find it harder to attract finan…
Sociālā uzņēmējdarbība: Starptautiskās pieredzes ieviešana
2021
Latvijā pastāv ienākumu nevienlīdzības problēma. Sociālās uzņēmējdarbības attīstība ir viens no soļiem šī jautājuma novēršanai. Tomēr nozare joprojām nav pietiekami attīstīta, un ir vajadzīga nobriedusi sociālās uzņēmējdarbības ekosistēma, lai radītu vairāk darbavietu un līdz minimumam samazinātu cilvēku grupas, kurām draud sociālā atstumtība. Šī darba mērķis ir izveidot labi funkcionējošas sociālās uzņēmējdarbības ekosistēmas teorētisko modeli Latvijā, balstoties uz Eiropas valstu pieredzi un vietējo sociālo uzņēmumu pētījumiem. Tiek analizēta Eiropas sociālās uzņēmējdarbības ekosistēmu prakse, ko var ieviest Latvijā, kā arī izaicinājumi, ar kuriem šodien saskaras sociālie uzņēmumi. Autore…
Sociālās un ekonomiskās ietekmes ezeru attīrīšanā un labiekārtošanā.
2015
Bakalaura darba „Sociālās un ekonomiskās ietekmes ezeru attīrīšanā un labiekārtošanā” mērķis ir izprast ezeru un to ekosistēmu nozīmīgumu, regulējošās un atbalsta funkcijas, izanalizēt sociālos un ekonomiskos ieguvumus veicot ieguldījumus ezera infrastruktūras un tur mītošo zivju sugu pavairošanas projektos. Bakalaura darba uzdevumos ietilpst ekosistēmu darbības principu apskate, šā brīža makšķerēšanas nozares un ezeru stāvokļa un to problēmu apzināšanās, kā arī ārzemēs veikto pētniecisko darbu analīze un aptaujas rezultātu analizēšana. Lai spētu sniegt ieteikumus Smiltenes ezeru attīrīšanas un labiekārtošanas plāna projekta realizēšanai, tiek izpētīts Katvaru ezera apsaimniekošanas modelis…