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941.
Regular fuel reduction burning is an important management strategy for reducing the scale and intensity of wildfires in south-west
Australian native forests, but the long term effects of this on tree and stand growth are not well understood. Five fire treatments,
including application of frequent and infrequent low intensity burns, and 25 years of fire exclusion, were applied to small
(4 ha) experimental plots in a low rainfall mixed jarrah (Eucalyptus marginata) and marri (Corymbia calophylla) forest to investigate the effects of these treatments on tree stem diameter growth, stand basal area increment and tree
mortality. Mean tree stem growth measured over 20 years was lowest in the long unburnt treatment compared with the burn treatments,
although surface soil nutrient levels were generally higher in the unburnt treatment, suggesting these sites may be moisture
limited. There was no clear pattern of the effects of the burn treatments, including the number of fires and the interval
between fires, on tree stem growth, stand basal area increment, crown health or mortality. These factors were strongly influenced
by dominance condition, with dominant and co-dominant trees growing most and suppressed trees growing least and experiencing
the highest mortality levels. There was no evidence of deteriorating tree or stand health that could be attributed to either
regular low intensity burning or to a long period (25 years) of fire exclusion. 相似文献
942.
Paul B. Thompson 《Journal of Agricultural and Environmental Ethics》2010,23(3):209-227
Recent publications by Pogge (Global ethics: seminal essays. St. Paul: Paragon House 2008) and by Singer (The life you can save: acting now to end world poverty. New York: Random House 2009) have resuscitated a debate over the justifiability of famine relief between Singer and ecologist Garrett Hardin in the 1970s.
Yet that debate concluded with a general recognition that (a) general considerations of development ethics presented more
compelling ethical problems than famine relief; and (b) some form of development would be essential to avoiding the problems
of growth noted by Hardin. Better than renewing the debate, we should recognize two points. First, food needs do indeed evoke
a moral response that is more direct and compelling than the philosophical positions often generated to rationalize a duty
to bring aid. As such the argument for feeding hungry people cannot be generalized into a paradigm for development ethics
without distortions that undercut the morally valid elements in Singer’s original argument. Second, contrary to prevailing
assumptions in present day development ethics, food aid and famine relief continue to be important priorities for international
agencies, notably the World Food Program. Emergency food assistance, the nominal topic of Singer’s original article, thus
is an important issue for agricultural as well as development ethics, though one that should indeed be seen as distinct from
more complex duties to address the conditions of chronic poverty and underdevelopment. 相似文献
943.
Ongoing eutrophication is changing the Baltic Sea ecosystem. Aquaculture causes relatively small-scale nutrient emissions,
but local environmental impact may be considerable. We used substance flow analysis (SFA) to identify and quantify the most
significant flows and stocks of nitrogen (N) and phosphorus (P) related to rainbow trout aquaculture in Finland. In 2004–2007,
the input of nutrients to the system in the form of fish feed was 829 t N year−1 and 115 t P year−1. Around one-fifth of these nutrients ended up as food for human consumption. Of the primary input, 70% ended up in the Baltic
Sea, directly from aquaculture and indirectly through waste management. The nutrient cycle could be closed partially by using
local fish instead of imported fish in rainbow trout feed, thus reducing the net load of N and P to a fraction. 相似文献
944.
945.
The Fallacies of Concurrent Climate Policy Efforts 总被引:1,自引:0,他引:1
Marian Radetzki 《Ambio》2010,39(3):211-222
Climate policy has assumed an extreme degree of urgency in the international debate in recent years. This article begins by
taking a critical look at the scientific underpinnings of the efforts to stabilize the climate. It points to several serious
question marks on the purported relationship between greenhouse gas emissions and global warming, and expresses distrust about
claims of impending catastrophes related to rising sea levels, hurricanes, and spread of infectious disease. It then reviews
the concurrent climate policy efforts and concludes that they are incoherent, misguided and unduly costly, and that they have
so far had no perceptible impact on anthropogenic greenhouse gas emissions. The exceedingly ambitious policy plans currently
under preparation suffer from similar fallacies. For these reasons, but also because of the remaining scientific doubts and
the exorbitant costs that have to be incurred, skepticism is expressed about the preparedness to implement the climate policy
plans currently on the table. 相似文献
946.
947.
Southern Chile encompasses one of the most extensive fjord regions of the world, the Patagonia, currently exposed to natural
and anthropogenic perturbations. These fjord ecosystems provide important services to humans, which have not been adequately
measured and valued. As a consequence, ecosystem services are commonly ignored in public policy design and in the evaluation
of development projects. Here we tackle questions that are highly relevant for the nation’s development, namely (1) understanding
fjord functioning, and (2) developing management strategies based on ecosystem services, in order to secure simultaneous and
adequate use of these ecosystems which area influenced by ecological (e.g., biogeochemical) and productive (e.g., aquaculture,
fisheries) processes. We also seek to strengthen the analysis of fjord ecosystem value from the economical (including coastal
zoning), socio-cultural, institutional, and governmental points of view. In addition, the investigation of current and future
effects of climate change on this large region offers a unique opportunity to understand the social and economic consequences
of a global phenomenon at local to regional scales. Biogeochemical and socio-economic models will be used to simulate future
scenarios under a gamut of management options. 相似文献
948.
During 19–20 October 2009, the Royal Swedish Academy of Sciences arranged the international symposium Energy 2050 in Stockholm. The symposium was held in association with the Swedish EU presidency in autumn 2009. Internationally renowned scientists assessed the energy issue in a broad perspective, with particular emphasis on the possibilities of a fossil-free future. The symposium focused on key topics emanating from the in-depth energy studies carried through by the Academy´s Energy Committee since 2005. The world community is facing a challenge of historic proportions to define a new energy paradigm based on fossil-energy substitutes. This article gives an overview of the current global energy situation (2007) and of the technologies which have the major potential for supplying energy up to year 2050 without jeopardizing the CO2 emission targets. 相似文献
949.
950.
Jan Atle Knutsen Halvor Knutsen Eli Rinde Hartvig Christie Torjan Bodvin Einar Dahl 《Ambio》2010,39(2):148-158
For many years, the planning and management of terrestrial areas has been supported by a detailed knowledge of the distribution
of habitats and their associated species. However, the detailed mapping of biological resources in extent coastal areas, such
as the Norwegian coastal zone, is unrealistic due to its enormous coastline. Here, we present a useful and feasible approach
and a set of simple, cost-effective methods which are suitable for providing a broad-scale overview of marine habitats and
fish resources. This approach was developed in conjunction with a pioneer study conducted along the southern coast of the
Skagerrak, where we combined knowledge gathered from local fishermen with scientific knowledge of important species and nature
types to establish a coastal sea mapping program. GIS modeling tools were used in both the mapping program and to integrate
local and scientific knowledge into digital maps made available to local area management. This multi-faceted approach, which
combines local knowledge and scientific methods, provides valuable information with respect to marine biodiversity, and has
been used extensively by local environmental management. 相似文献