Search results for "Ecosystem"
showing 10 items of 1752 documents
Tree species influences diversity of ground-dwelling insects in afforested fields
2015
Abstract Impaired natural ecosystems, such as agricultural lands, are restored toward original or other target stage. Because the long agricultural history has changed the physical, chemical and biological features of the soil, afforested fields can harbor novel species assemblages and interactions. Our overall aim was to quantify the diversity of ground beetles and ants in early successional afforested fields. In a large scale field experiment, we compared plots that had been afforested 25 years ago by planting monocultures of birch, pine or spruce trees. A total of 4080 carabid individuals representing 41 species, and 131,933 ant individuals representing 15 species were recorded. Both the…
Is it possible to understand a book missing a quarter of the letters? Unveiling the belowground species richness of grasslands
2022
Abstract Knowledge of species richness patterns in plant communities is biased toward its hidden belowground part and is derived only from the part visible aboveground. Studies on the relationship of the above- to belowground parts of plant communities suffer from the lack of a consistent and uniform approach to assess their taxonomic composition, particularly in species-rich ecosystems. This study described the proportion between above- and belowground parts of vegetation in three grassland types along with the environmental factors that affect them, using eDNA metabarcoding and an observer survey. The internal transcribed spacer 2 (ITS2) region was used to analyze the total plant richness…
Towards a framework for assessment and management of cumulative human impacts on marine food webs
2015
Effective ecosystem-based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic threats holistically, it is necessary to know how threats affect different components within ecosystems and ultimately alter ecosystem functioning. We used a case study of a Mediterranean seagrass (Posidonia oceanica) food web and expert knowledge elicitation in an application of the initial steps of a framework for assessment of cumulative human impacts on food webs. We produced a conceptual seagrass food web model, determined the main trophic relationships, identified the main threats to the fo…
Labile nitrogen, carbon, and phosphorus pools and nitrogen mineralization and immobilization rates at low temperatures in seasonally snow-covered soi…
2006
Surface mineral horizons from four ecosystems sampled in the northwestern Italian Alps were incubated at −3 and +3°C to simulate subnivial and early thaw period temperatures for a seasonally snow-covered area. The soil profiles at these sites represent extreme examples of management, grazed meadow (site M) and extensive grazing beneath larch (site L) or naturally disturbed by avalanche and colonized by alder (site A) and the expected forest climax vegetation beneath fir (site F). Changes in labile pools of nitrogen (N) and phosphorus (P) were active at all sites at both temperatures during 14 days of laboratory incubation. Ammonium was the dominant inorganic form of total dissolved N (TDN),…
Dimensiones del Ecosistema Digital Universitario: Validación del Instrumento «University Digital Ecosystem» (UN-DIGECO) / Dimensions of the Universit…
2020
El presente estudio presenta el diseño y validación del instrumento UN-DIGECO (University Digital Ecosystem), orientado a conocer el Ecosistema Digital Universitario, identificando las dimensiones asociadas al uso que hacen los estudiantes de los medios sociales (MMSS) y/o aplicaciones digitales. La validación de contenido y comprensión se efectuó en tres fases: construcción, refinado y validación psicométrica, mediante el análisis factorial confirmatorio, apoyado en el constructo teórico inicial. Se diseñaron ítems –recabando información de instrumentos similares-, acordes a indicadores adscritos a seis dimensiones: aprendizaje, interacción social, creación de contenidos, consumo online, o…
Inovācijas ekosistēmas raksturojums Latvijas un Eiropas Savienības kontekstā, izmantojot Latvijas autonomo auto inovācijas ekosistēmas gadījuma analī…
2018
Maģistra darba „Inovācijas ekosistēmas raksturojums Latvijas un Eiropas Savienības kontekstā, izmantojot Latvijas autonomo auto inovācijas ekosistēmas gadījuma analīzi” mērķis ir izmantojot autonomā auto inovācijas ekosistēmas gadījuma analīzi, raksturot inovācijas ekosistēmas īpatnības Latvijā un identificēt galvenos faktorus, kuri kavē aktieru produktīvu sadarbību inovācijas ekosistēmas ietvaros Latvijā. Darba ietvaros izvirzīti sekojoši pētnieciskie jautājumi: Kādi faktori ietekmē inovācijas ekosistēmas produktivitāti Latvijā? Kādas ir būtiskākās barjeras, kas kavē inovācijas ekosistēmas spēju radīt vērtību Latvijā? Mērķa sasniegšanai apskatīti starptautiskie pētījumi, inovācijas ekosist…
Domini collettivi, forme di autogoverno per la gestione degli ecosistemi e lo sviluppo locale
2020
One of the most ancient forms of self-government of environmental systems is that relating to the management of civic uses and collective lands, in which a specific local community controls and manages sustainable resources (fields, pastures, woods, etc.) sustainably and efficiently. The paper aims to briefly retrace the salient stages of the history of collective domains, and to explore their value as “goods that are produced by long co-evolutionary processes between human settlement and environment” (Magnaghi 2015, 139) highlighting the appearance of complex socio-ecological systems (SES). Finally, using the theory developed by Elinor Ostrom to analyze the sustainability of SES (Ostrom 20…
Soil carbon in Mediterranean ecosystems and related management problems
2011
Relaciones suelo-vegetación en una toposecuencia del Escudo Guayanés, Venezuela
2014
El Escudo Guayanés es uno de los territorios más antiguos del planeta; tiene millones de años sometido a procesos de lixiviación y erosión que dejan suelos oligotróficos. El objetivo de este trabajo fue hacer la caracterización de los parámetros físicos y químicos de los suelos, en diferentes comunidades boscosas de la Reserva Forestal Imataca, e identificar ciertas relaciones entre los componentes edáficos y las especies que allí se presentan. Se realizó un inventario de todos los individuos mayores a 10cm dap (diámetro a la altura del pecho) en 15 parcelas (1ha); en cada una de esas parcelas se evaluaron cuatro sub-parcelas de sotobosque (100m²) para contabilizar todas las espermatofitas;…
Global urban environmental change drives adaptation in white clover
2022
Made available in DSpace on 2022-04-28T19:52:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-03-18 Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied am…