A novel approach to optimize management strategies for carbon stored in both forests and wood products   总被引：3，自引：0，他引：3  

Chris R. Hennigar  David A. MacLean  Luke J. Amos-Binks 《Forest Ecology and Management》2008,256(4):786-797

We present a new approach to maximize carbon (C) storage in both forest and wood products using optimization within a forest management model (Remsoft Spatial Planning System). This method was used to evaluate four alternative objective functions, to maximize: (a) volume harvested, (b) wood product C storage, (c) forest C storage, and (d) C storage in the forest and products, over 300 years for a 30,000 ha hypothetical forest in New Brunswick, Canada. Effects of three initial forest age-structures and a range of product substitution rates were tested. Results showed that in many cases, C storage in product pools (especially in landfills) plus on-site forest C was equivalent to forest C storage resulting from reduced harvest. In other words, accounting for only forest, and not products and landfill C, underestimates true forest contributions to C sequestration, and may result in spurious C maximization strategies. The scenario to maximize harvest resulted in mean harvest for years 1–200 of 3.16 m³ ha⁻¹ yr⁻¹ and total C sequestration of 0.126 t ha⁻¹ yr⁻¹, versus 0.98 m³ ha⁻¹ yr⁻¹ and 0.228 t ha⁻¹ yr⁻¹ for a scenario to maximize forest C. When maximizing total (forest + products) C, mean harvest and total C storage for years 1–200 was 173% and 5% higher, respectively, than when maximizing forest C; and 218% and 6% higher, respectively, when maximizing substitution benefits (0.25 t of avoided C emissions per m³ of lumber used) in addition to total C. Initial forest age-structure affected harvest in years 1–50 < 34% among the four alternative management objective scenarios, and resulted in mean C sequestration rates of 0.31, 0.10, and −0.14 t ha⁻¹ yr⁻¹ when maximizing total C storage for young, even-aged, and old forests, respectively. Our results reinforce the importance of including products in forest-sector C budgets, and demonstrate how including product C in management can maximize forest contributions toward reduced atmospheric CO₂ at operational scales.  相似文献   

Compensating for development: Orang Asli experiences of Malaysia's Sungai Selangor dam     

Luke Swainson  Andrew McGregor 《Asia Pacific viewpoint》2008,49(2):155-167

Abstract: In 2001, two indigenous Orang Asli communities living in Peninsula Malaysia were forced to leave their homelands to make way for the Sungai Selangor dam. The dam, built to resolve water shortages in Kuala Lumpur, came with a comprehensive compensation package designed to alleviate the hardships faced by the displaced communities. This paper explores the discursive and material impacts of these compensation packages. We argue that the emerging literature on compensation for displaced people values the same sorts of economic and social criteria as the Malaysian government does in its pursuit of modernising the Orang Asli. Their shared belief that effective compensation would improve the quality of life for affected communities above pre‐displacement levels helped to publicly legitimise the dam‐building project. Interviews with the displaced communities, however, found stark differences in community satisfaction which have more to do with losses of intrinsic place‐based cultural and spiritual values, for which there may be no effective or adequate compensation, than social and economic criteria. We conclude that compensation programmes will always struggle to effectively cope with these less tangible place‐based values and that open acknowledgement of this weakness is required if alternatives to displacement‐inducing development projects are to be more readily considered.  相似文献   

干旱胁迫对南疆膜下滴灌棉田光合产物累积的影响     

吴凤全  王亮  林涛  王静  郭瑞霞  岳璐珂  汤秋香 《西北农业学报》2016,25(11):1636-1642

为明确适度干旱胁迫对新疆南部极端干旱区滴灌棉花生长及水分利用效率的影响。在常规滴灌(灌水量为4 650 m~3·hm~(-2))的基础上,设计4种减量滴灌模式(灌水量分别2 250、2 850、3 450和4 050m~3·hm~(-2)),分析不同滴灌量对棉花光合产物积累动态及产量形成的影响。结果表明,随着滴灌量的减少,蕾铃数比常规灌水量减少;蕾铃脱落率先减少后增加;根冠比呈现先增大后减小的趋势,在始花期滴灌量3 450m~3·hm~(-2)的根冠比大于常规滴灌处理;随灌溉量减少,干物质呈现先增加后减少的趋势,灌溉量为2 250~4 050m~3·hm~(-2)时干物质显著增加,常规灌水量下干物质量则呈下降趋势。随着灌水量的减少,单铃质量、单株结铃数也随着减小,从而阻碍棉花经济产量的提高。  相似文献   

Effects of diets on the growth performance and shell pigmentation of Pacific abalone          下载免费PDF全文

Zhi Yong Ju  Cecilia Viljoen  Peter Hutchinson  Justin Reinicke  F David Horgen  Luke Howard  Cheng‐Sheng Lee 《Aquaculture Research》2016,47(12):4004-4014

This study investigated the effects of natural and artificial diets on growth performance and shell pigmentation of cultured abalone. A 7‐month feeding trial was conducted on 12 000 Pacific abalones (Haliotis discus hannai) with four diets including two extruder‐processed test diets (with & without addition of oleopaprika carotenoids), Pacific dulse (Palmaria mollis) and a combination of Pacific dulse and a test diet. The results showed that the two test diets resulted in higher survival of abalone, but with a lower growth rates when compared with Pacific dulse alone (P < 0.05). The combination diet achieved the highest survival and growth rates. The Pacific dulse resulted in abalone with dark‐brown shells, which are preferred by Asian markets. The test diets led to 52% and 55% of the animals with pink coloured shells and the supplementation of oleopaprika did not affect shell pigmentation. The aqueous acidic extracts from both dark‐brown and pink shells showed blue colour; HPLC‐MS chromatography revealed that the pigments in the extracts were consistent with a biliverdin and a cysteine‐biliverdin. These results are valuable for the development of abalone feed and the control of abalone shell colouration.  相似文献   

Fall armyworm [Spodoptera frugiperda (J.E. Smith)] damage in maize: management options for flood-recession cropping smallholder farmers     

Moreblessing Chimweta  Luke Jimu  Arnold Bray Mashingaidze 《国际虫害防治杂志》2020,66(2):142-154

Abstract

We determined fall armyworm abundance, infestation and damage on maize in smallholder farmers’ fields in the Zambezi Valley in northern Zimbabwe. Data were collected through field measurements at four sites and interviews with 101 farmers. Fall armyworm abundance ranged from 13.7 to 33.3 larvae per 30 plants, with infestation exceeding 94% and leaf, silk and tassel damage levels ranging between 25 and 50%. Most larvae on maize plants (P?<?0.05) were at instar stages 2 to 3. Estimated grain yield decrease was 58%. Echinochloa colona and Amaranthus spp. were also damaged by fall armyworm. Farmers experimented with 28 combinations of pesticides, ash, and washing powders. Sixty five percent of the farmers used restricted to highly restricted pesticides. High fall armyworm abundance, infestation and maize damage levels suggest that the Zambezi Valley could become a fall armyworm hotspot. Sequential damage of plant parts signified the persistence of this pest in the study area. We recommend large-scale interventions that include chemical and biological control methods as well as destroying ratoon hosts, publishing information about locally available pesticides for the control of fall armyworm, and farmer training on fall armyworm biology and correct use of pesticides.  相似文献   

Sterilization of sea lice eggs with ultraviolet C light: towards a new preventative technique for aquaculture     

Luke T Barrett  Cassandra G Pert  Samantha Bui  Frode Oppedal  Tim Dempster 《Pest management science》2020,76(3):901-906

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Reservoir to river: Quantifying fine-scale fish movements after translocation     

Luke Carpenter-Bundhoo  Gavin L. Butler  Tom Espinoza  Nick R. Bond  Stuart E. Bunn  Mark J. Kennard 《Ecology of Freshwater Fish》2020,29(1):89-102

Translocation of individuals is a widely used tool in the conservation of threatened species. The movement behaviours of translocated individuals in their new environment are a key factor that can influence translocation success (i.e. survival and reproduction). In this study, eel-tailed catfish (Tandanus tandanus) and Murray cod (Maccullochella peelii) movements were monitored using fine-scale acoustic telemetry over a 5-month period in two lowland rivers in eastern Australia. Fine-scale movement and habitat selection were compared among translocated lacustrine and resident riverine T. tandanus and between species. We found no difference in fine-scale movement behaviours between translocated and resident T. tandanus; however, there was some variation in movement response to environmental variation between species. In contrast, habitat selection varied not only between the two species, but also between resident and translocated T. tandanus individuals. Notably, activity was significantly lower in the first day after release compared to the remainder of the study period. Although T. tandanus translocated from a reservoir had never experienced the environmental fluctuations of a riverine system, individuals still responded in the same way as resident riverine fish, suggesting an innate behavioural response. However, this was not the case for habitat selection, where translocated individuals preferred habitats more common in their source population's lacustrine environment. The findings of this study are important in guiding future conservation efforts involving the translocation of wild-caught fish, primarily the importance of the suitable habitat at the release site to ensure the success and persistence of translocated populations.  相似文献   

Carbon and trace element mobility in an urban soil amended with green waste compost     

Luke Beesley  Nicholas Dickinson 《Journal of Soils and Sediments》2010,10(2):215-222

Background, aim and scope  

The amendment of degraded urban soils using recycled organic wastes offers potential improvements to physicochemical status and functionality, but there is a paucity of knowledge on the potential impact on residual contaminants in soil. The aim of this study was to evaluate the mobility of trace metals and arsenic (As) through an urban soil following amendment with green waste compost over an annual cycle.  相似文献   

Virulence genes in bla(CTX-M) Escherichia coli isolates from chickens and humans     

Randall L  Wu G  Phillips N  Coldham N  Mevius D  Teale C 《Research in veterinary science》2012,93(1):23-27

The aim of this study was to determine the presence of virulence genes in isolates of CTX-M Escherichia coli from diseased chickens, from healthy chickens and from urinary tract infections in people. Three CTX-M E. coli strains from three different instances of disease in poultry (two of which were E. coli related) were tested for bla(CTX-M) sequence type and replicon type. Additionally, they were tested for the presence of 56 virulence genes (encoding fimbriae, adhesins, toxins, microcins and iron acquisition genes) using a micro-array. Results were compared to the virulence genes present in isolates from 26 healthy chickens and from 10 people with urinary tract infections. All genes found in isolates from diseased birds, including the astA (heat stable toxin) and tsh (temperature sensitive haemagglutinin) genes which have previously been associated with colibacillosis in chickens, were also present in isolates from healthy birds. However, 6/10 of the virulence genes found were exclusive to isolates from humans. Genes exclusive to chicken isolates included ireA (sidephore receptor), lpfA (long polar fimbriae), mchF (microcin transporter protein) and tsh whilst genes exclusive to human isolates included ctdB (cytolethal distending toxin), nfaE (non-fimbrial adhesion), senB (plasmid encoded enterotoxin) and toxB (toxin B). The results support previous findings that CTX-M E. coli strains in chickens are generally different from those causing disease in humans, but genes such as astA and tsh in isolates from diseased birds with colisepticaemia were also present in isolates from healthy birds.  相似文献   

The initial discovery of thorny-headed worms in sheep     

Langrová I  Lukešova D  Baruš V  Vadlejch J  Válek P  Jankovska I  Petrtýl M  Kubík S  Cadková Z  Kudrnáčová M 《Veterinary parasitology》2012,184(2-4):381-383

Acanthocephalans belonging to the species Acanthocephalus lucii were found in the colon of a lamb from ecological farms in the Czech Republic. The main determination features used for these acanthocephalans are the shape and size of the hooks as well as the number of hooks on the proboscis. Three immature specimens measured 5.0-13.2mm in length; the appearance of the acanthocephalan body (in the studied material) suggests that passage through this unusual host causes the cystacanths to slightly increase in length. In the case of the lambs examined, the infection may be acquired through the accidental ingestion of the intermediate host - waterlouse (Asellus aquaticus).  相似文献