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351.
Reptile and arboreal marsupial response to replanted vegetation in agricultural landscapes. 总被引:1,自引:0,他引:1
Ross B Cunningham David B Lindenmayer Mason Crane Damian Michael Christopher MacGregor 《Ecological applications》2007,17(2):609-619
We report reptile and arboreal marsupial responses to vegetation planting and remnant native vegetation in agricultural landscapes in southeastern Australia. We used a hierarchical survey to select 23 landscapes that varied in the amounts of remnant native vegetation and planted native vegetation. We selected two farms within each landscape. In landscapes with plantings, we selected one farm with and one farm without plantings. We surveyed arboreal marsupials and reptiles on four sites on each farm that encompassed four vegetation types (plantings 7-20 years old, old-growth woodland, naturally occurring seedling regrowth woodland, and coppice [i.e., multistemmed] regrowth woodland). Reptiles and arboreal marsupials were less likely to occur on farms and in landscapes with comparatively large areas of plantings. Such farms and landscapes had less native vegetation, fewer paddock trees, and less woody debris within those areas of natural vegetation. The relatively large area of planting on these farms was insufficient to overcome the lack of these key structural attributes. Old-growth woodland, coppice regrowth, seedling regrowth, and planted areas had different habitat values for different reptiles and arboreal marsupials. We conclude that, although plantings may improve habitat conditions for some taxa, they may not effectively offset the negative effects of native vegetation clearing for all species, especially those reliant on old-growth woodland. Restoring suitable habitat for such species may take decades to centuries. 相似文献
352.
Steve W. Ross Tara L. Casazza Andrea M. Quattrini Kenneth J. Sulak 《Marine Biology》2007,150(4):681-695
The distinctive larval stage of eels (leptocephalus) facilitates dispersal through prolonged life in the open ocean. Leptocephali are abundant and diverse off North Carolina, yet data on distributions and biology are lacking. The water column (from surface to 1,293 m) was sampled in or near the Gulf Stream off Cape Hatteras, Cape Lookout, and Cape Fear, North Carolina during summer through fall of 1999–2005, and leptocephali were collected by neuston net, plankton net, Tucker trawl, and dip net. Additional samples were collected nearly monthly from a transect across southern Onslow Bay, North Carolina (from surface to 91 m) from April 2000 to December 2001 by bongo and neuston nets, Methot frame trawl, and Tucker trawl. Overall, 584 tows were completed, and 224 of these yielded larval eels. The 1,295 eel leptocephali collected (combining all methods and areas) represented at least 63 species (nine families). Thirteen species were not known previously from the area. Dominant families for all areas were Congridae (44% of individuals, 11 species), Ophichthidae (30% of individuals, 27 species), and Muraenidae (22% of individuals, ten species). Nine taxa accounted for 70% of the overall leptocephalus catches (in order of decreasing abundance): Paraconger caudilimbatus (Poey), Gymnothorax ocellatus Agassiz complex, Ariosoma balearicum (Delaroche), Ophichthus gomesii (Castelnau), Callechelys muraena Jordan and Evermann, Letharchus aliculatus McCosker, Rhynchoconger flavus (Goode and Bean), Ophichthus cruentifer (Goode and Bean), Rhynchoconger gracilior (Ginsburg). The top three species represented 52% of the total eel larvae collected. Most leptocephali were collected at night (79%) and at depths > 45 m. Eighty percent of the eels collected in discrete depth Tucker trawls at night ranged from mean depths of 59–353 m. A substantial number (38% of discrete depth sample total) of larval eels were also collected at the surface (neuston net) at night. Daytime leptocephalus distributions were less clear partly due to low catches and lower Tucker trawl sampling effort. While net avoidance may account for some of the low daytime catches, an alternative explanation is that many species of larval eels occur during the day at depths > 350 m. Larvae of 21 taxa of typically shallow water eels were collected at depths > 350 m, but additional discrete depth diel sampling is needed to resolve leptocephalus vertical distributions. The North Carolina adult eel fauna (estuary to at least 2,000 m) consists of 51 species, 41% of which were represented in these collections. Many species of leptocephali collected are not yet known to have juveniles or adults established in the South Atlantic Bight or north of Cape Hatteras. Despite Gulf Stream transport and a prolonged larval stage, many of these eel leptocephali may not contribute to their respective populations. 相似文献
353.
We studied the lipid dynamics (lipid contents, classes and fatty acids) during oogenesis and early embryogenesis of 7 viviparous
and 3 oviparous deepwater chondrichthyans. Mature pre-ovulated ovarian follicles of all species were high in lipid content,
indicative of large energetic expenditure and high maternal investment. Larger lipid reserves were found in viviparous dogshark
(28–36% wet weight, ww) compared to oviparous chimaeras (19–24% ww) and catshark, F. boardmani (18% ww). Neutral lipids and monounsaturated fatty acids were the main source of lipidic energy during vitellogenesis and
gestation. For most species, there was a peak in total lipid content, levels of storage lipids and essential fatty acids at
time of ovulation. Interspecific variation of total lipid yolk reserves and lipid class profiles was largely explained by
differences in parity mode, reproductive (continuous vs. non-continuous oocytes development) strategy and depth-related physiological adaptations. Fatty acid profiles were less variable
among species with the most important fatty acids including: 16:0, 18:1ω9, 20:1ω9, 20:4ω6 and 22:6ω3. These findings provide
a greater biochemical understanding of different maternal-embryonic relationships among chondrichthyans, which can be used
as a baseline for subsequent comparative studies. 相似文献
354.
355.
David T. Alien Terry Foecke Howard Klee Jr. W. B. Beck Lawrence L. Ross Arthur H. Purcell 《Journal of the Air & Waste Management Association (1995)》2013,63(9):1159-1167
The 1992 A&WMA Critical Review was authored by Harry Freeman and members of his staff at the Pollution Prevention Research Branch, Risk Reduction Engineering Laboratory, U.S. Environmental Protection Agency in Cincinnati, Ohio. Mr. Freeman presented the paper "Industrial Pollution Prevention," at the Critical Review session held during the 85th Air & Waste Management Association Annual Meeting in Kansas City, Missouri. Prepared discussions and invited comments presented during the session are published here, as well as closing remarks by Mr. Freeman. 相似文献
356.
Ralph T. Ross 《Journal of environmental science and health. Part. B》2013,48(6):665-676
Abstract This report discusses the responsibilities of government for the legislation of pesticides, and describes the impact of various statutes on the use of pesticides in agriculture. Governmental responsibilities for management of the economy, education, and enactment of laws and regulations are discussed, and the history of U.S. legislation of pesticides and related substances is presented. Finally, the impact of pesticide regulation on international trade is considered. 相似文献
357.
Ross C 《Environmental monitoring and assessment》2004,99(1-3):267-274
Loss of vegetation production in arid lands has been difficult to remediate and has signifi- cant economic impacts on human
populations. Restoration efforts based on non-local materials and large-scale mechanization have not been capable of efficiently
reversing the trend of environmental degradation. The use of traditional knowledge and simplified methods of seed harvesting,
storing, marketing and soil preparation have proven that regeneration of native species and efficient land reclamation is
possible in areas that have traditionally been considered degraded beyond redemption. This paper describes a method of land
reclamation that combines tradition and simple mechanics that can be applied in all arid areas that face desertification.
Because the work builds on cultural practices long used in non-industrialized societies, it is particularly adapted to rural
areas. The methods described have the potential to open new low-tech economic opportunities to all segments of local non-urban
populations while combating desertification and creating a more ecologically sound environment. 相似文献
358.
Wiebke E. Krämer Verena Schrameyer Ross Hill Peter J. Ralph Kai Bischof 《Marine Biology》2013,160(3):563-577
This study examined the capacity for photoprotection and repair of photo-inactivated photosystem II in the same Symbiodinium clade associated with two coexisting coral species during high-light stress in order to test for the modulation of the symbiont’s photobiological response by the coral host. After 4 days exposure to in situ irradiance, symbionts of the bleaching-sensitive Pocillopora damicornis showed rapid synthesis of photoprotective pigments (by 44 %) and strongly enhanced rates of xanthophyll cycling (by 446 %) while being insufficient to prevent photoinhibition (sustained loss in F v/F m at night) and loss of symbionts after 4 days. By contrast, Pavona decussata showed no significant changes in F v/F m, symbiont density or xanthophyll cycling. Given the association with the same Symbiodinium clade in both coral species, our findings suggest that symbionts in the two species examined may experience different in hospite light conditions as a result of different biometric properties of the coral host. 相似文献
359.
J.V. Ross 《Ecological modelling》2010,221(21):2515-2520
We present two ‘rules of thumb’ for metapopulation management. The first identifies an explicit formula for the persistence time of the population, and thus enables the population manager to form a priority species ranking by identifying those species most at risk of extinction. The second identifies an optimal management strategy that gives direction on how to alter the colonisation rate (creation or improvement of habitat corridors) and local extinction rate (restoring habitat quality or expanding habitat) in order to maximise the persistence time under a budgetary constraint. We employ a simple stochastic version of Levins (1969) metapopulation model, which is first calibrated to a more realistic spatial model. Our rules are tested on computer-generated patch networks and a model for malleefowl (Leipoa ocellata) in the Bakara region of South Australia. 相似文献