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81.
Trends of summer precipitation and summer temperature and their influence on trends in summer drought and area burned in British Columbia (BC) were investigated for the period 1920–2000. The complexity imposed by topography was taken into account by incorporating high spatial resolution climate and fire data. Considerable regional variation in trends and in climate–fire relationships was observed. A weak but significant increase in summer temperature was detected in northeastern and coastal BC, whereas summer precipitation increased significantly in all regions—by up to 45.9 %. A significant decrease in province-wide area burned and at the level of sub-units was strongly related to increasing precipitation, more so than to changing temperature or drought severity. A stronger dependence of area burned on precipitation, a variable difficult to predict, implies that projected changes in future area burned in this region may yield higher uncertainties than in regions where temperature is predominantly the limiting factor for fire activity. We argue that analyses of fire–climate relationships must be undertaken at a sufficiently high resolution such that spatial variability in limiting factors on area burned like precipitation, temperature, and drought is captured within units.  相似文献   
82.
Public engagement in local environmental planning and decision-making is often advocated on various grounds, both instrumental and normative. Yet in developed countries in the context of renewable energy infrastructure deployment, place attachment, place identity and place-protective action continue to be implicated in public objection. We set out an interdisciplinary change readiness hypothesis of specifically how local participatory scenario or visioning processes that include climate mitigation measures may support the mobilisation of place attachment for climate mitigation, including renewable energy deployment. We hypothesise that local visioning may support movement towards change readiness by helping to anchor unfamiliar social representations of low carbon energy infrastructure and new patterns of urban form in existing, more positive representations of localities and associated attachments. To this end, seeking ways to modify threat perceptions relating to climate change and renewable energy infrastructure is advocated as a key direction for study.  相似文献   
83.
The pygidial gland secretion of the rove beetle genera Stenus Latreille and Dianous Leach is composed of pyridine and piperidine-derived alkaloids and several terpene compounds. Two-choice bioassays with ants and fish, as well as agar diffusion assays, revealed that the secretion compounds are capable of deterring predators and protecting the beetles from infestation with microorganisms. In addition, the beetles use the secretion for rapid movements on the water surface, a process called skimming. Thus, originally developed to chemically defend the sensitive unprotected abdomen from predator attacks, the secretion of recent Steninae can be designated as multifunctional. Four of the alkaloid compounds occur as different configurational isomers in the secretion. Two-choice tests showed that ants discriminate between stereoisomers of stenusine, while there was no effect visible on bacteria in agar diffusion assays. Furthermore, there are evolutionary trends within the Steninae concerning the secretion composition, as some of the alkaloids primarily occur in phylogenetically basal species, while others are mainly restricted to derived species.  相似文献   
84.
An organism’s pattern of resource allocation to reproduction and growth over time critically impacts on its lifetime reproductive success. During times of low resource availability, there are two fundamental, mutually exclusive strategies of energy investment: maintenance of somatic tissues to support survival and later reproduction or investment into an immediate reproductive event at the risk of subsequent death. Here, we examine energy allocation patterns in the coral Montipora digitata to determine whether energy investment during periods of resource shortage favours growth or reproduction in a sessile, modular marine species. We manipulated light regimes (two levels of shading) on plots within a shallow reef flat habitat (Orpheus Island, Great Barrier Reef, Australia) and quantified energy uptake (rates of net photosynthesis), energy investment into reproduction (E R ), tissue growth per unit surface area (E T ) and energy channelled into calcification (E C ). With declining resource availability (i.e. reduced photosynthesis), relative energy investment shifted from high (~80%) allocation to tissue growth (E R :E T :E C  = 11:81:8%) to an increasing proportion channelled into reproduction and skeletal growth (20:31:49%). At the lowest light regime, calcification was maintained but reproduction was halted and thus energy content per unit surface area of tissue declined, although no mortality was observed. The changing hierarchy in energy allocation among life functions with increasing resource limitation found here for an autotrophic coral, culminating in cessation of reproduction when limitations are severe, stands in contrast to observations from annual plants. However, the strategy may be optimal for maximising fitness components (growth, reproduction and survival) through time in marine modular animals.  相似文献   
85.
Environment Systems and Decisions - Organizational and technical approaches have proven successful in increasing the performance and preventing risks at socio-technical systems at all scales....  相似文献   
86.
87.
It has been confirmed that the NOx-concentration in air is highest over industrial areas and that it decreases by more than 75%, parallel to traffic density, over urban areas as related to forested areas. A significant correlation excists between NO2-concentration and the parameters of “traffic density,” followed by “road density” and “number of inhabitants/km2” in urban areas. No positive correlation was found with the number of “registered cars” and the parameters of “land use”. In forested areas, the traffic density correlated with the NO2-concentration, but the correlation was not significant. The other parameters had no positive correlation with NO2-concentration. In forest, urban- and industrial-areas, the NOx-concentration in the air had a fairly constant ratio to traffic density.  相似文献   
88.
The goal of this paper was to statistically explore the spatiotemporal performance of remotely sensed actual evapotranspiration (ETa) datasets and a remotely sensed ensemble in a region that lacks observed data. The remotely sensed datasets were further compared with ETa results from a physically based hydrologic model (Soil and Water Assessment Tool) to examine the differences and determine the level of agreement between the ETa datasets and the model outputs. ETa datasets were compared on temporal (i.e., monthly and seasonal basis) and spatial (i.e., landuse) scales at both watershed and subbasin levels. The results showed a lack of consistent similarities and differences among the datasets when evaluating the monthly ETa variations; however, the seasonal aggregated data presented more consistent similarities and differences during the spring and summer compared to the fall and winter. Meanwhile, spatial analysis of the datasets showed the MOD16A2 500 m ETa product was the most versatile of the tested datasets, being able to differentiate between landuses during all seasons. Furthermore, the use of an averaging ensemble was able to improve overall ETa performance in the study area. This study showed that the remotely sensed ETa products are not similar throughout the year, but the appropriate application periods for different ETa products were identified. Finally, spatial variabilities of the ETa products are more in tune with landuse and climate characteristics.  相似文献   
89.
The objective of the present study was to set up a small-scale pilot reactor at ONGC Hazira, Surat, for capturing CO2 from vent gas. The studies were carried out for CO2 capture by either using microalgae Chlorella sp. or a consortium of microalgae (Scenedesmus quadricauda, Chlorella vulgaris and Chlorococcum humicola). The biomass harvested was used for anaerobic digestion to produce biogas. The carbonation column was able to decrease the average 34 vol.% of CO2 in vent gas to 15 vol.% of CO2 in the outlet gas of the carbonation column. The yield of Chlorella sp. was found to be 18 g/m2/day. The methane yield was 386 l CH4/kg VSfed of Chlorella sp. whereas 228 l CH4/kg VSfed of the consortium of algae.  相似文献   
90.
Lanthanum-modified bentonite clay (Phoslock(?) is a lake remediation tool designed to strip dissolved phosphorus (P) from the water column and increase the sediment P-sorption capacity. This study investigated short term alterations in sediment elemental composition and sediment P-fractions based on sediment cores taken 2 days before and 28 days following the application of 24 t of Phoslock? to a 9 ha, man-made reservoir. Following the application, sediment lanthanum (La) content increased significantly (p < 0.05; n = 4) in the top 8 cm of the sediment, thereby theoretically increasing sediment P-binding capacity on the whole reservoir scale by 250 kg. Mass balance calculations were used to estimate the theoretical binding of release-sensitive P (P(mobile); sum of 'labile P', 'reductant-soluble P' and 'organic P' fraction) by La across the top 4 cm and 10 cm depth of sediment. The amended mass of La in the sediment had the potential to bind 42% of P(mobile) present in the top 4 cm or 17% of P(mobile) present in the top 10 cm. However, with the exception of a significant increase (p<0.05; n=4) in the 'residual P' fraction in the top 2 cm, sediment P-fractions, including P(mobile,) did not differ significantly following the Phoslock? application. Experimental P-adsorption studies indicated P-saturation values for Phoslock? of 21,670 mg P kg?1 Phoslock?. Sequential extraction of P from saturated Phoslock? under laboratory conditions indicated that around 21% of P bound by Phoslock? was release-sensitive, while around 79% of bound P was unlikely to be released under reducing or common pH (5-9) conditions in shallow lakes. Applying Phoslock? is, therefore, likely to increase the P-sorption capacity of sediments under reducing conditions.  相似文献   
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