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61.
Urban stream restoration continues to be used as an ecological management tool, despite uncertainty about the long‐term sustainability and resilience of restored systems. Evaluations of restoration success often focus on specific instream indicators, with limited attention to the wider basin or parallel hydrologic and geomorphic process. A comprehensive understanding of urban stream restoration progress is particularly important for comparisons with nonurban sites as urban streams can provide substantial secondary benefits to urban residents. Here, we utilize a wide range of indicators to retrospectively examine the restoration of Nine Mile Run, a multi‐million dollar stream restoration project in eastern Pittsburgh (Pennsylvania, USA). Examination of available continuous hydrological data illustrates the high cost of failures to incorporate the data into planning and adaptive management. For example, persistent extreme flows drive geomorphic degradation threatening to reverse hydrologic connections created by the restoration and impact the improved instream biotic communities. In addition, human activities associated with restoration efforts suggest a positive feedback as the stream restoration has focused effort on the basin beyond the reach. Ultimately, urban stream restoration remains a potentially useful management tool, but continued improvements in post‐project assessment should include examination of a wider range of indicators.  相似文献   
62.
Hawaii’s game animals are all non-native species, which provokes human–wildlife conflict among stakeholders. The management of human–wildlife conflict in Hawaii is further complicated by the discrete nature of island communities. Our goal was to understand the desires and perceived values or impacts of game held by residents of Hawaii regarding six game species [pigs (Sus scrofa), goats (Capra hircus), mouflon (Ovis musimon), axis deer (Axis axis), turkeys (Melagris gallopavo), and doves (Geopelia striata)]. We measured the desired abundance of game on the six main Hawaiian Islands using the potential for conflict index and identified explanatory variables for those desires via recursive partitioning. In 2011 we surveyed 5,407 residents (2,360 random residents and 3,047 pre-identified stakeholders). Overall 54.5 and 27.6 % of the emailed and mailed surveys were returned (n = 1,510). A non-respondent survey revealed that respondents and non-respondents had similar interest in wildlife, and a similar education level. The desired abundance of game differed significantly among stakeholders, species, and islands. The desired abundance scores were higher for axis deer, mouflon, and turkeys compared to pigs, goats or doves. Enjoyment at seeing game and the cultural value of game were widespread explanatory variables for desired abundance. Models for Lanai emphasized the economic value of game, whereas models for Maui identified the potential for game to contaminate soil and water. Models for Oahu and Kauai revealed concern for human health and safety. Given our findings we recommend managers design separate management plans for each island taking into consideration the values of residents.  相似文献   
63.
There is renewed interest in re-establishing trees on 0.6 million ha of mining-disturbed lands in the Appalachian mountains of Eastern United States. Many coal-mined lands reclaimed to meet requirements of US federal law have thick herbaceous vegetation and compacted soils which impede tree establishment. Mitigation practices were applied on three mine sites and evaluated for success in enabling planted trees to become established. Eastern white pine (Pinus strobus), hybrid poplar (Populus deltoids × Populus trichocarpa), and mixed Appalachian hardwoods were established using weed control only and weed control with subsoil ripping. Trees were measured in October of 2008 after 5 years of growth. Subsoil ripping increased mixed hardwood survival from 43 to 71 %, hybrid poplar biomass index from 1.51 to 8.97 Mg ha?1, and Eastern white pine biomass index from 0.10 to 0.32 Mg ha?1. When restoring trees to unused mined sites, subsoil ripping can aid survival and growth to an extent that will result in a valuable forest.  相似文献   
64.
This paper presents the results from a post-auditing study-a comparison of the predictions of environmental impacts of projects made in environmental statements prior to developmentwith those that actually occurred upon or after development. The purpose of post-auditing is to provide an analysis of prediction performance in environmental impact assessment and thus to improve future practice by learning from experience. By means of a combination of site visits, interviews and document scrutiny, 865 predictions from 28 UK projects granted planning permission were examined. Of these, 488 (56%) were auditable, of which 383 (79%) were deemed 'accurate' or 'nearly accurate' and 105 (21%) 'inaccurate'. The remaining 377 (44%) predictions were not auditable, the main reasons being lack of data, vague or ambiguous predictions and time dependency.There were only six unpredicted impacts. The study reveals some encouraging findings, but also a number of discouraging ones, which indicate the need to increase both enthusiasm for, and implementationof, post-auditing activities. Several suggestions are made to help achieve these objectives.  相似文献   
65.
Oyster populations in south Florida estuaries have declined in part through altered salinity driven by anthropogenic changes in freshwater inputs. In particular, the St. Lucie Estuary (SLE) in southeastern Florida has suffered widespread loss of oyster habitat. With efforts underway to improve water quality and oyster habitat in the SLE, the goal of this study was to develop a model to assess ecosystem level impacts of oyster restoration. Phytoplankton and oyster biomass modeling targets were established from observational data collected from 2005 to 2009. Modeled oyster biomass production and filtration fluctuated with temperature, salinity, and total suspended solids from a combination of observational and predicted input functions in 10-year simulations (1998–2007). Model estimates of oyster biomass fluctuated with salinity from near zero after extreme freshwater discharge in 2002–2003 and 2004–2005 to maximum values near 150.0 and 200.0 g?C?m?2 in spring 1999 and fall 2006. There was potential for algal blooms as turnover time for the phytoplankton standing stock (15.6 days) was faster than water mass turnover (21.0 days). While >1,000 days were required for 50 ha of oyster habitat to filter the entire volume of the estuarine segment, filter time reduced to <20 days with an estimated fivefold increase in net consumption of phytoplankton if the oyster habitat was increased to 300 ha. Re-establishment of biologically desirable salinity envelopes would stabilize oyster survival allowing the possibility for successful habitat restoration to benefit water quality and faunal attributes of the St. Lucie Estuary.  相似文献   
66.
Abstract

The total alkaloid content and individual alkaloid composition were determined by colorimetry and high performance liquid chromatography, respectively, for Canadian triticale and barley ergot (Claviceps purpurea). The total alkaloid content was highly variable between individual sclerotia from the same or different sources and ranged from 0.042 to 0.752% for triticale and from 0.082 to 1.04% for barley; average values were 0.239% for Ottawa triticale, 0.289% for Prairie triticale, and 0.264% for barley. Ergocristine and its isomer ergocristinine were the major constituents in both grains. On average, Canadian ergot pooled from rye, wheat, triticale, and barley consists of ergocristine (31%), ergocristinine (13%), ergocristinine (13%), ergotamine (17%), ergotaminine (8%), ergocryptine (5%), ergocryptinine (3%), ergo‐metrine (5%), ergometrinine (2%), ergosine (4%), ergosinine (2%), ergocornine (4%), ergocorninine (2%), and unidentified alkaloids (3%) and an average total alkaloid content of 0.236%. With the exception of rye and barley ergot from the maritime regions, Canadian rye, wheat, triticale, and barley ergot is fairly uniform in individual alkaloid composition.  相似文献   
67.
68.
Abstract: One major factor leading to the imperilment of freshwater mussels ( Bivalvia, Unionidae) has been the large-scale impoundment of rivers. We examined the distribution and abundance of mussels at 37 sites along a 240-km length of the Little River in southeastern Oklahoma, U.S.A., which is affected by both mainstem and tributary reservoirs. We observed a mussel extinction gradient downstream from impoundments in this river: with increasing distance from the mainstem reservoir there was a gradual, linear increase in mussel species richness and abundance. Mussel species distributions were significantly nested, with only sites furthest from the impoundment containing relatively rare species. Below the confluence with the inflow from the second reservoir these same trends were apparent but much weaker, and overall mussel abundance was greatly reduced. Our results suggest that considerable stream lengths are necessary to overcome the effects of impoundment on mussel populations, and such information should be considered in conservation and management plans.  相似文献   
69.
Victoria enacted EIA legislation in 1978, before any other state in Australia. The current EIA system, which is administered by the state government, is based upon non-mandatory guidelines which are far more comprehensive than the provisions of the law they elaborate. As it has matured, Victoria's EIA system has developed requirements for the consideration of alternatives, screening, scoping (with project-specific outlines), EIA report-quality checks, proponent response to public comment and the preparation of a ministerial assessment report containing recommendations. The use of consultative committees to advise on scoping and EIA report preparation is one of several public participation provisions. EIA system evaluation criteria are advanced and used to help in reviewing the largely discretionary Victorian system, elements of which could serve as an example to other jurisdictions with incomplete EIA legislative requirements, such as the U.K.  相似文献   
70.
The purpose of this work was to study the mechanisms involved in free radical activation of thermal mechanical pulp (TMP) fibers with the ultimate goal of developing methods for bonding wood fiber without the use of traditional adhesives. The generation of hydroxyl radicals in a mediated Fenton system was studied using electron spin resonance (ESR) spin-trapping techniques and indirectly through chemiluminescence measurement. The activation of TMP fibers was also evaluated by ESR measurement of free phenoxy radical generation on solid fibers. The results indicate that low molecular weight chelators can improve Fenton reactions, thus in turn stimulating the free radical activation of TMP fibers. However, it was also shown that excessive and prolonged free radical treatment may cause the destruction of fiber phenoxy radicals. In conclusion, this study demonstrates the potential for application, but also the complexity of free radical chemistry in biological materials, especially with regard to the chelation of transition metals and the interaction between free radicals.  相似文献   
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