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1.
Sci Total Environ ; 705: 135817, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31841925

RESUMO

This paper applies a social metabolism framework and energy flow analysis for evaluating agroecosystem and land use transitions in food-energy-water systems using the Upper Snake River Basin (USBR), Idaho, USA as a case-study. The study area is one of the primary agricultural regions of the State of Idaho. Dairy products are the primary agricultural outputs of the region; therefore, we modified a biomass accounting framework to explicitly incorporate the role of manure in the agroecosystem. Despite the increase of cropland between 2002 and 2012 in the basin, a decrease in energy input was observed for crop production. An increase in the industrial energy inputs for dairy production, on the other hand, showed that the basin is a clear example of a metabolic industrialized farm system - an example of land use intensification. We compare the energy return on investments (EROIs) as an indicator of agroecosystem transition for both crop and dairy production during the period 2002 to 2012. Contrary to our expectations, the analysis suggests that livestock production is a relatively energy efficient process in land management in the basin. This is due to the reuse of nutrient by-products from livestock as well as the refuse and residues from crop farming. At the same time, the findings provide insights on the percentage of manure to be reinvested as compost that would improve energy production efficiency. However, the reuse of manure, as it is managed in the basin, may have a negative implication on the nutrient balance of the agroecosystem that needs further investigation. Nonetheless, there is market potential for the reuse and reinvestment of biomass to make energy production in the basin more efficient.


Assuntos
Rios , Agricultura , Fazendas , Idaho , Água
2.
Bioscience ; 66(2): 130-146, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29593361

RESUMO

Wildland fire management has reached a crossroads. Current perspectives are not capable of answering interdisciplinary adaptation and mitigation challenges posed by increases in wildfire risk to human populations and the need to reintegrate fire as a vital landscape process. Fire science has been, and continues to be, performed in isolated "silos," including institutions (e.g., agencies versus universities), organizational structures (e.g., federal agency mandates versus local and state procedures for responding to fire), and research foci (e.g., physical science, natural science, and social science). These silos tend to promote research, management, and policy that focus only on targeted aspects of the "wicked" wildfire problem. In this article, we provide guiding principles to bridge diverse fire science efforts to advance an integrated agenda of wildfire research that can help overcome disciplinary silos and provide insight on how to build fire-resilient communities.

4.
Environ Manage ; 36(5): 726-40, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16206024

RESUMO

We developed logistic regression models from data on biotic and abiotic variables for 172 sites on Banks Peninsula, New Zealand, to predict the probability of occurrence of two diadromous fish, banded kokopu (Galaxias fasciatus) and koaro (G. brevipinnis). Banded kokopu occurrence was positively associated with small streams and low-intensity land uses (e.g., sheep grazing or forested), whereas intensive land uses (e.g., mixed sheep and cattle farming) and lack of riparian forest cover impacted negatively on occurrence at sampled sites. Also, if forests were positioned predominantly in lowland areas, banded kokopu occurrence declined with increasing distance to stream mouth. Koaro occurrence was positively influenced by catchment forest cover, high stream altitudes, and areas of no farming activity or mixed land uses. Intensive land uses, distance to stream mouth, and presence of banded kokopu negatively influenced koaro occupancy of stream reaches. Banded kokopu and koaro presence was predicted in 86.0% and 83.7% agreement, respectively, with field observations. We used the models to quantify the amount of stream reaches that would be of good, moderate, and poor quality, based on the probability of occurrences of the fish being greater than 0.75, between 0.75 and 0.5, or less than 0.5, respectively. Hindcasting using historical data on vegetation cover undertaken for one catchment, Pigeon Bay, showed they would have occupied most of the waterway before anthropogenic modification. We also modeled potential future scenarios to project potential fish distribution.


Assuntos
Conservação dos Recursos Naturais/métodos , Ecossistema , Peixes/fisiologia , Sistemas de Informação Geográfica , Migração Animal , Animais , Simulação por Computador , Água Doce , Modelos Logísticos , Nova Zelândia , Especificidade da Espécie , Árvores/fisiologia
5.
J Environ Manage ; 68(2): 207-18, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12781760

RESUMO

Human activities levy a biological cost on ecosystems as resources are accessed and utilized at rates which are often incompatible with inherent ecosystem processes and structures. The recreational impact of humans upon intertidal zones and particularly fucoid algal assemblages is one major threat facing coastal ecosystems. The effect of human values, knowledge and perception in effecting biologically costly behaviors has rarely been examined. We hypothesize that with respect to intertidal zones: (1) Personal attribution and perception of ecosystem resiliency are more important than knowledge in determining the extent of depreciative behaviors individuals engage in, and; (2) Individuals who are uncertain about ecosystem resiliency will behave in a manner consistent with the 'precautionary principle'. We measured the depreciative behavior, and the attitudes and perceptions to ecosystem resilience, of visitors to Wick Headland in Pacific Rim National Park, British Columbia. Attitudes, knowledge, perceptions, and personal attribution were measured using questionnaire survey and structured interviews undertaken in situ. Depreciative behaviors of visitors were discreetly observed and correlated to the questionnaire survey and interview responses. We show that visitors who recorded greater knowledge of intertidal ecology engaged in more depreciative behaviors than visitors recording less knowledge. Visitors who perceived high ecosystem resilience in the intertidal zone engaged in significantly more behaviors eliciting biological cost than those who perceived low ecosystem resilience. Visitors who recorded uncertainty regarding ecosystem resilience engaged in significantly more depreciative behaviors than those who perceived low ecosystem resilience but slightly fewer depreciative behaviors than those who perceived high ecosystem resilience. Personal attribution was inversely correlated to the mean number of depreciative behaviors. We discuss the relevance of these results to the management of intertidal zones and marine protected areas, to multiple use management, the management of visitor impact, and natural resource use.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Conhecimentos, Atitudes e Prática em Saúde , Opinião Pública , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Coleta de Dados , Poluentes Ambientais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ilhas do Pacífico , Dinâmica Populacional , Recreação
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