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161.
Time series of abundance estimates are commonly used for analyses of population trends and possible shifts in growth rate.
We investigate if trends in age composition can be used as an alternative to abundance estimates for detection of decelerated
population growth. Both methods were tested under two forms of density dependence and different levels of environmental variation
in simulated time series of growth in Baltic gray seals. Under logistic growth, decelerating growth could be statistically
confirmed after 16 years based on population counts and 14 years based on age composition. When density dependence sets in
first at larger population sizes, the age composition method performed dramatically better than population counts, and a decline
could be detected after 4 years (versus 10 years). Consequently, age composition analysis provides a complementary method
to detect density dependence, particularly in populations where density dependence sets in late. 相似文献
162.
De Jaeger S Eyckmans J Rogge N Van Puyenbroeck T 《Waste management (New York, N.Y.)》2011,31(7):1429-1440
We study the impact of some local policies aimed at municipal solid waste (MSW) reduction on the cost efficiency of MSW collection and disposal. We explicitly account for differences between municipalities in background conditions by using a bootstrapped version of the Data Envelopment Analysis methodology in combination with a matching technique. Using data on 299 municipalities in Flanders, Belgium, for the year 2003, our results indicate that municipalities that are member of a waste collection joint venture, or that subscribe to a voluntary agreement to reduce MSW at the highest ambition level, collect and process MSW more efficiently than other municipalities. Weekly instead of two-weekly waste collection, or using a weight-based pricing system appears to have no impact on efficiency. Our results show that aiming at MSW reduction does not lead to lower efficiency of public service provision, even on the contrary. 相似文献
163.
Johan De Tavernier 《Journal of Agricultural and Environmental Ethics》2009,22(4):383-388
164.
Johan Eriksson Ulf Skyllberg 《Environmental pollution (Barking, Essex : 1987)》2009,157(11):3010-3015
Aniline and 2,4,6-trinitrotoluene (TNT) were equilibrated with particulate (POM) and dissolved organic matter (DOM) from an organic soil at different compositions of adsorbed major cations (Na, Al) and pH (aniline: 3.7–5.1, TNT: 4.8–5.0). After separation of POM, concentrations of 14C-labelled aniline and TNT* (including TNT degradation products) were determined in DOM size fractions using size-exclusion chromatography (SEC) and UV-detection. Concentrations in the <3.5 kDa size fraction were 2.8–6.0 and 8.5–9.5 times higher for aniline and TNT*, respectively, as compared to the >40 kDa fraction. Thus, both aniline and TNT* were preferentially associated to the smallest DOM size fraction. The significant binding to DOM (similar extent as to POM) and the fact that the <3.5 kDa DOM fraction was less susceptible to flocculation by major metals suggests that the mobility of aniline and TNT is highly affected by the solubility of soil organic matter. 相似文献
165.
Anna Christiansson Johan Eriksson Daniel Teclechiel Åke Bergman 《Environmental science and pollution research international》2009,16(3):312-321
Background, aim, and scope Decabromodiphenyl ether (DecaBDE) is used as an additive flame retardant in polymers. It has become a ubiquitous environmental
contaminant, particularly abundant in abiotic media, such as sediments, air, and dust, and also present in wildlife and in
humans. The main DecaBDE constituent, perbrominated diphenyl ether (BDE-209), is susceptible to transformations as observed
in experimental work. This work is aimed at identifying and assessing the relative amounts of products formed after UV irradiation
of BDE-209.
Materials and methods BDE-209, dissolved in tetrahydrofuran (THF), methanol, or combinations of methanol/water, was exposed to UV light for 100
or 200 min. Samples were analyzed by gas chromatography/mass spectrometry (electron ionization) for polybrominated diphenyl
ethers (PBDEs), dibenzofurans (PBDFs), methoxylated PBDEs, and phenolic PBDE products.
Results The products formed were hexaBDEs to nonaBDEs, monoBDFs to pentaBDFs, and methoxylated tetraBDFs to pentaBDFs. The products
found in the fraction containing halogenated phenols were assigned to be pentabromophenol, dihydroxytetrabromobenzene, dihydroxydibromodibenzofuran,
dihydroxytribromodibenzofuran, and dihydroxytetrabromodibenzofuran. The PBDEs accounted for approximately 90% of the total
amount of substances in each sample and the PBDFs for about 10%.
Discussion BDE-209 is a source of PBDEs primarily present in OctaBDEs but also to some extent in PentaBDEs, both being commercial products
now banned within the EU and in several states within the USA. It is notable that OH-PBDFs have not been identified or indicated
in any of the photolysis studies performed to date. Formation of OH-PBDFs, however, may occur as pure radical reactions in
the atmosphere.
Conclusions Photolysis of decaBDE yields a wide span of products, from nonaBDEs to hydroxylated bromobenzenes. It is evident that irradiation
of decaBDE in water and methanol yields OH-PBDFs and MeO-PBDFs, respectively. BDE-202 (2,2′,3,3′,5,5′,6,6′-octabromodiphenyl
ether) is identified as a marker of BDE-209 photolysis.
Recommendations and perspectives BDE-209, the main constituent of DecaBDE, is primarily forming debrominated diphenyl ethers with higher persistence which
are more bioaccumulative than the starting material when subjected to UV light. Hence, DecaBDE should be considered as a source
of these PBDE congeners in the environment.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
166.
On the decline of ground lichen forests in the Swedish boreal landscape: Implications for reindeer husbandry and sustainable forest management 总被引:1,自引:0,他引:1
Per Sandström Neil Cory Johan Svensson Henrik Hedenås Leif Jougda Nanna Borchert 《Ambio》2016,45(4):415-429
Lichens are a bottleneck resource for circumpolar populations of reindeer, and as such, for reindeer husbandry as an indigenous Sami land-use tradition in northern Sweden. This study uses ground lichen data and forest information collected within the Swedish National Forest Inventory since 1953, on the scale of northern Sweden. We found a 71 % decline in the area of lichen-abundant forests over the last 60 years. A decline was observed in all regions and age classes and especially coincided with a decrease of >60 year old, open pine forests, which was the primary explanatory factor in our model. The effects of reindeer numbers were inconclusive in explaining the decrease in lichen-abundant forest. The role that forestry has played in causing this decline can be debated, but forestry can have a significant role in reversing the trend and improving ground lichen conditions.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-015-0759-0) contains supplementary material, which is available to authorized users. 相似文献167.
Tomas Lundmark Johan Bergh Annika Nordin Nils Fahlvik Bishnu Chandra Poudel 《Ambio》2016,45(2):203-213
Continuous-cover forestry (CCF) has been recognized for the production of multiple ecosystem services, and is seen as an alternative to clear-cut forestry (CF). Despite the increasing interest, it is still not well described how CCF would affect the carbon balance and the resulting climate benefit from the forest in relation to CF. This study compares carbon balances of CF and CCF, applied as two alternative land-use strategies for a heterogeneous Norway spruce (Picea abies) stand. We use a set of models to analyze the long-term effects of different forest management and wood use strategies in Sweden on carbon dioxide emissions and carbon stock changes. The results show that biomass growth and yield is more important than the choice of silvicultural system per se. When comparing CF and CCF assuming similar growth, extraction and product use, only minor differences in long-term climate benefit were found between the two principally different silvicultural systems. 相似文献
168.
Microrefugia are sites that support populations of species when their ranges contract during unfavorable climate episodes. Here, we review and discuss two aspects relevant for microrefugia. First, distributions of different species are influenced by different climatic variables. Second, climatic variables differ in the degree of local decoupling from the regional climate. Based on this, we suggest that only species limited by climatic conditions decoupled from the regional climate can benefit from microrefugia. We argue that this restriction has received little attention in spite of its importance for microrefugia as a mechanism for species resilience (the survival of unfavorable episodes and subsequent range expansion). Presence of microrefugia will depend on both the responses of individual species to local climatic variation and how climate-forcing factors shape the correlation between local and regional climate across space and time. 相似文献
169.
Yeong Sheng Tey Elton Li Johan Bruwer Amin Mahir Abdullah Mark Brindal Alias Radam Mohd Mansor Ismail Suryani Darham 《Sustainability Science》2014,9(1):17-29
This study develops the understanding of the adoption of sustainable agricultural practices (SAPs) by investigating the relative importance of a set of multidimensional factors in the Malaysian vegetable production sector. A factor approach is deployed to identify explanatory indicators within an integrative framework that is synthesized from the theory of interpersonal behavior and the theory of diffusion of innovation. We achieved this by analyzing a logistic regression model for the adoption of six individual SAPs (conservation tillage, intercropping, cover crops/mulches, crop rotation, organic fertilizers/composts, and integrated pest management). The findings indicate that adoption depends on a range of socio-economic, agro-ecological, institutional, informational, and psychological factors, as well as the perceived attributes of SAPs. Fundamental policy understanding of the issue should, therefore, be multidisciplinary. In addition, standardized coefficients reveal that the impact of statistically significant factors on adoption is unequal. In general, the most influential factor is the asymmetric distribution of resources across geographical locations. This is followed by financial capital and a number of factors, including the workforce size, the usefulness of information, Chinese ethnicity, and the perceived relative advantage of SAPs. Guided by this prioritization understanding, future SAPs promotion now has a better opportunity to target the more important areas. Similar research effort should be made to steer sustainable agriculture internationally. 相似文献
170.
Agneta Andersson H. E. Markus Meier Matyas Ripszam Owen Rowe Johan Wikner Peter Haglund Kari Eilola Catherine Legrand Daniela Figueroa Joanna Paczkowska Elin Lindehoff Mats Tysklind Ragnar Elmgren 《Ambio》2015,44(3):345-356
Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2–4 °C warming and 50–80 % decrease in ice cover by 2100. Precipitation may increase ~30 % in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants and decreased salinity. Coupled physical–biogeochemical models indicate that, in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, thus promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favored by AOM, while phytoplankton production may be reduced. Extra trophic levels in the food web may increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider the effects of climate change on the ecosystem dynamics and functions, as well as the effects of anthropogenic nutrient and pollutant load. Monitoring should have a holistic approach, encompassing both autotrophic (phytoplankton) and heterotrophic (e.g., bacterial) processes. 相似文献