877 resultados para Arboreal adaptation
Resumo:
Resumen tomado de la publicaci??n
Resumo:
Resumen tomado de la publicaci??n
Resumo:
Resumen tomado de la publicaci??n
Resumo:
Resumen tomado de la publicaci??n
Resumo:
New Zealand is a nation of Migrants. Immigrants have played a significant role in the country’s economic growth and cultural development. With a population of four million people, New Zealand’s population is becoming increasingly culturally diverse. Almost one in five New Zealanders were born overseas, rising to one in three in its largest city, Auckland. Asians are the fastest growing ethnic group, increasing by around 140% since 1996. Indians account for 1.2% of the population (Statistics New Zealand, 2002). The Goan community in New Zealand is relatively small and its size is not formally recorded, however, anecdotally it appears to have grown to over 200 families in the Auckland area, with most arriving after 1996. For women who migrate, loneliness and isolation have been identified as the most ‘glaring’ experience and this is intensified by the loss of extended family networks when they migrate to a country where nuclear families are the norm (Leckie, 1995). The creation of new networks and maintenance of prior networks in new ways is crucial to the successful settlement and integration into a new country. This paper reports on how Goan, Indian women in Auckland, New Zealand used specific strategies to manage the adjustment to living in a new country. The findings reveal that participants used a variety of skills to settle in New Zealand such as cultivating a “can do” attitude, obtaining support and learning. These skills enabled them to move beyond their own culture and begin to take active part in New Zealand culture. However, this process was not immediate and the participants passed through a number of stages along a continuum of settlement and integration. These stages will be discussed below and situated within a body of literature.
Resumo:
This paper is a review of a study to evaluate the usefulness of a laboratory approach to auditory training with hearing impaired children.
Resumo:
Edaphic variables figure significantly in plant community adaptations in tropical ecosystems but are often difficult to resolve because of the confounding influence of climate. Within the Chiquibul forest of Belize, large areas of Ultisols and Inceptisols occur juxtaposed within a larger zone of similar climate, permitting unambiguous assessment of edaphic contributions to forest composition. Wet chemical analyses, X-ray diffraction and X-ray fluorescence spectroscopy were employed to derive chemical (pH, exchangeable cations, CEC, total and organic C, total trace elements) and physical (texture, mineralogy) properties of four granite-derived Ustults from the Mountain Pine Ridge plateau and four limestone-derived Ustepts from the San Pastor region. The soils of these two regions support two distinct forests, each possessing a species composition reflecting the many contrasting physicochemical properties of the underlying soil. Within the Mountain Pine Ridge forest, species abundance and diversity is constrained by nutrient deficiencies and water-holding limitations imposed by the coarse textured, highly weathered Ultisols. As a consequence, the forest is highly adapted to seasonal drought, frequent fires and the significant input of atmospherically derived nutrients. The nutrient-rich Inceptisols of the San Pastor region, conversely, support an abundant and diverse evergreen forest, dominated by Sabal mauritiiformis, Cryosophila stauracantha and Manilkara spp. Moreover, the deep, fine textured soils in the depressions of the karstic San Pastor landscape collect and retain during the wet season much available water, thereby serving as refugia during particularly long periods of severe drought. To the extent that the soils of the Chiquibul region promote and maintain forest diversity, they also confer redundancy and resilience to these same forests and, to the broader ecosystem, of which they are a central part. (C) 2005 Elsevier B.V. All rights reserved.
Resumo:
Testing of the Integrated Nitrogen model for Catchments (INCA) in a wide range of ecosystem types across Europe has shown that the model underestimates N transformation processes to a large extent in northern catchments of Finland and Norway in winter and spring. It is found, and generally assumed, that microbial activity in soils proceeds at low rates at northern latitudes during winter, even at sub-zero temperatures. The INCA model was modified to improve the simulation of N transformation rates in northern catchments, characterised by cold climates and extensive snow accumulation and insulation in winter, by introducing an empirical function to simulate soil temperatures below the seasonal snow pack, and a degree-day model to calculate the depth of the snow pack. The proposed snow-correction factor improved the simulation of soil temperatures at Finnish and Norwegian field sites in winter, although soil temperature was still underestimated during periods with a thin snow cover. Finally, a comparison between the modified INCA version (v. 1.7) and the former version (v. 1.6) was made at the Simojoki river basin in northern Finland and at Dalelva Brook in northern Norway. The new modules did not imply any significant changes in simulated NO3- concentration levels in the streams but improved the timing of simulated higher concentrations. The inclusion of a modified temperature response function and an empirical snow-correction factor improved the flexibility and applicability of the model for climate effect studies.
Resumo:
The impacts of climate change on nitrogen (N) in a lowland chalk stream are investigated using a dynamic modelling approach. The INCA-N model is used to simulate transient daily hydrology and water quality in the River Kennet using temperature and precipitation scenarios downscaled from the General Circulation Model (GCM) output for the period 1961-2100. The three GCMs (CGCM2, CSIRO and HadCM3) yield very different river flow regimes with the latter projecting significant periods of drought in the second half of the 21st century. Stream-water N concentrations increase over time as higher temperatures enhance N release from the soil, and lower river flows reduce the dilution capacity of the river. Particular problems are shown to occur following severe droughts when N mineralization is high and the subsequent breaking of the drought releases high nitrate loads into the river system. Possible strategies for reducing climate-driven N loads are explored using INCA-N. The measures include land use change or fertiliser reduction, reduction in atmospheric nitrate and ammonium deposition, and the introduction of water meadows or connected wetlands adjacent to the river. The most effective strategy is to change land use or reduce fertiliser use, followed by water meadow creation, and atmospheric pollution controls. Finally, a combined approach involving all three strategies is investigated and shown to reduce in-stream nitrate concentrations to those pre-1950s even under climate change. (c) 2006 Elsevier B.V. All rights reserved.