Natural resources of miombo woodland and recent changes in agricultural and land-use practices     

R.M. Lawton 《Forest Ecology and Management》1982,4(3):287-297

Miombo woodland covers a large area of central Africa, south of the equator. The renewable natural resources of miombo, i.e., timber, poles, wood fuel, beeswax and honey, mushrooms, edible caterpillars, wild fruits and livestock browse are discussed and roughly evaluated. A brief account is given of the salient ecological features of miombo, including the role of fire and its timing in determining the tree population dynamics, and the parts played by tsetse fly and wildlife populations in the history of human occupation in the region.Under the traditional system of agriculture practised in northern Zambia, a form of shifting cultivation known as chitimene, the woodland is the agricultural fallow. Owing to population growth, changes in social attitudes and economic considerations, the chitimene system can no longer be practised. An important aspect of the changes taking place is the replacement of finger millet, a grain relatively rich in protein, by maize, giving a poorer diet and resulting in the need for measures to restore soil fertility periodically. One such measure discussed is the introduction of an edible leguminous fallow crop to maintain productivity.with the inevitable reduction in the area of the miombo woodlands which accompanies the changes in the agricultural system, their natural resources are becoming scarcer. Their importance in the economy is not appreciated by the people until there is a local shortage.The value of exotic pine and eucalyptus plantations, which grow well in the high rainfall areas (1000 mm⁺), and their economic future are considered.  相似文献   

A computed tomographic study of endodontic and apical changes in 81 equine cheek teeth with sagittal fractures     

Kieran J. Rowley  Neil B. Townsend  Yu-Mei R. Chang  Andrew R. Fiske-Jackson 《Equine veterinary journal》2022,54(3):541-548

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Animal populations in relation to their food resources: edited by Adam Watson. British Ecological Society Symposium Number 10. Blackwells,Oxford & Edinburgh: xx + 477 pp., numerous text figures, 23 × 14 cm, £5.00, 1970     

J.H. Lawton 《Biological conservation》1972

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Ecological experiments with model systems     

Lawton JH 《Science (New York, N.Y.)》1995,269(5222):328-331

Some of the classic experiments in ecology have involved real organisms interacting in the laboratory, that is, model systems. Ecologists are increasingly using model systems to investigate problems of global environmental change and questions about the assembly, persistence, and stability of complex communities. Model laboratory systems are a halfway house between mathematical models and the full complexity of the field, and they yield powerful insights into the dynamics of populations and ecosystems.  相似文献   

Cervico-vaginal mucus (CVM) – an accessible source of immunologically informative biomolecules     

Mounir Adnane  Kieran G. Meade  Cliona O’Farrelly 《Veterinary research communications》2018,42(4):255-263

Cervico-vaginal mucus (CVM), the product of epithelial cells lining the uterus, cervix and vagina, is secreted to facilitate uterine lubrication and microbial clearance. Predominantly composed of water and mucins, CVM also contains high levels of immuno-active proteins such as immunoglobulin A (IgA), lactoferrin and lysozyme which protect against infection by blocking adhesion and mediating microbial killing. The repertoire of cytokines, chemokines and antimicrobial peptides is predominantly generated by the secretions of endometrial epithelial cells into the uterine lumen and concentrated in the CVM. The quantity and relative proportions of these inflammatory biomarkers are affected by diverse factors including the estrus cycle and health status of the animal and therefore potentially provide important diagnostic and prognostic indicators. We propose that measuring molecular signatures in bovine CVM could be a useful approach to identifying and monitoring genital tract pathologies in beef and dairy cows.  相似文献   

Effect of plastic occlusive clips used as an alternative to mulesing on breech conformation, body weight and survival of Merino lambs     

Evans I  Lawton P  Sergeant E  Lloyd J 《Australian veterinary journal》2012,90(3):88-96

Objective To determine the effect of applying plastic clips to the breech and tail of lambs on the perineal and tail bare areas, breech wrinkle, dag (faecal) accumulation, urine stain, body weight and survival of lambs, compared with unclipped, unmulesed lambs and mulesed lambs. Method The study was conducted on five commercial wool‐growing farms in southern Australia. On each study site lambs (2–12‐weeks‐old) were divided into three groups: (1) unclipped, unmulesed control (tail dock only); (2) treated with clips; and (3) treated with the mules operation. Evaluations of effects, including visual scoring, bare area measurements and body weight, were performed before treatment and on or approximately days 30, 60, 90 and 180 after treatment. On each occasion, lambs were recorded as either present or absent to allow estimates of survival. Results The clip treatment increased the size of the perineal and tail bare areas compared with the unclipped, unmulesed control lambs (P < 0.05), although the increases were less than in mulesed lambs (P < 0.05). The clips reduced breech wrinkle, dag and urine stain to levels partway between those recorded in the unclipped, unmulesed controls and the mulesed lambs (P < 0.05). Clipped lambs weighed more than mulesed lambs after treatment (days 30–90 P < 0.001; day 180 P < 0.01) and had higher cumulative percentage survival to 90 days after treatment (P = 0.03). Conclusions The clips successfully modified the breech region of lambs, although the changes were less than with mulesing. The clips did not reduce the body weight of lambs, compared with the unclipped, unmulesed control lambs, and improved 90‐day cumulative percentage survival compared with mulesed lambs.  相似文献   

Toward sustainable harvest strategies for marine fisheries that include recreational fishing     

Ashley M. Fowler  Natalie A. Dowling  Jeremy M. Lyle  Josep Alós  Leif E. Anderson  Steven J. Cooke  Andy J. Danylchuk  Keno Ferter  Heath Folpp  Clifford Hutt  Kieran Hyder  Daniel K. Lew  Michael B. Lowry  Tim P. Lynch  Nicholas Meadows  Estanis Mugerza  Kjell Nedreaas  Domingos Garrone-Neto  Faith A. Ochwada-Doyle  Warren Potts  David Records  Scott Steinback  Harry V. Strehlow  Sean R. Tracey  Michael D. Travis  Jun-ichi Tsuboi  Jon Helge Vølstad  Rowan C. Chick 《Fish and Fisheries》2023,24(6):1003-1019

Recreational fishing (RF) is a large yet undervalued component of fisheries globally. While progress has been made in monitoring, assessing, and managing the sector in isolation, integration of RF into the management of multi-sector fisheries has been limited, particularly relative to the commercial sector. This marginalises recreational fishers and reduces the likelihood of achieving the sector's objectives and, more broadly, achieving fisheries sustainability. We examined the nature and extent of RF inclusion in harvest strategies (HSs) for marine fisheries across 15 regions in 11 nations to define the gap in inclusion that has developed between sectors. We focused on high-income nations with a high level of RF governance and used a questionnaire to elicit expert knowledge on HSs due to the paucity of published documents. In total, 339 HSs were considered. We found that RF inclusion in HSs was more similar to the small-scale sector (i.e., artisanal, cultural, or subsistence) than the commercial sector, with explicit operational objectives, data collection, performance indicators, reference points, and management controls lacking in many regions. Where specified, RF objectives focused on sustainability, economic value and catch allocation rather than directly relating to the recreational fishing experience. Conflicts with other sectors included competition with the commercial sector for limited resources, highlighting the importance of equitable resource allocation policies alongside HSs. We propose that RF be explicitly incorporated into HSs to ensure fisheries are ecologically, economically, and socially sustainable, and we recommend that fisheries organisations urgently review HSs for marine fisheries with a recreational component to close the harvest strategy gap among sectors.  相似文献   

Impacts of rising atmospheric carbon dioxide on model terrestrial ecosystems   总被引：2，自引：0，他引：2  

TH Jones  LJ Thompson  JH Lawton  TM Bezemer  RD Bardgett  TM Blackburn  KD Bruce  PF Cannon  GS Hall  SE Hartley  G Howson  CG Jones  C Kampichler  E Kandeler  DA Ritchie 《Science (New York, N.Y.)》1998,280(5362):441-443

In model terrestrial ecosystems maintained for three plant generations at elevated concentrations of atmospheric carbon dioxide, increases in photosynthetically fixed carbon were allocated below ground, raising concentrations of dissolved organic carbon in soil. These effects were then transmitted up the decomposer food chain. Soil microbial biomass was unaffected, but the composition of soil fungal species changed, with increases in rates of cellulose decomposition. There were also changes in the abundance and species composition of Collembola, fungal-feeding arthropods. These results have implications for long-term feedback processes in soil ecosystems that are subject to rising global atmospheric carbon dioxide concentrations.  相似文献   

Improved filtration method to isolate pure populations of primary bovine endometrial epithelial and stromal cells for immunological studies     

Kelly  Paul  Barry-Reidy  Anne  Brewer  Amy  Meade  Kieran G.  O’Farrelly  Cliona 《Veterinary research communications》2020,44(1):29-39

Veterinary Research Communications - Isolation and culture of distinct primary endometrial cells are key to reliable in-vitro models to investigate the uterine immune response and optimse new...  相似文献   

Antiangiogenic therapy and p53     

Browder T  Folkman J  Hahnfeldt P  Heymach J  Hlatky L  Kieran M  Rogers MS 《Science (New York, N.Y.)》2002,297(5581):471; discussion 471

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