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51.
Christopher J Bonar Ernesto O Boede Manuel García Hartmann Joanne Lowenstein-Whaley Esmeralda Mujica-Jorquera Scott V Parish James V Parish Michael M Garner Cynthia K Stadler 《Journal of zoo and wildlife medicine》2007,38(2):177-191
River dolphins are especially susceptible to negative human impacts. For their conservation, attempts of relocation or procreation ex situ may become important in the future to avoid their extinction. Additional knowledge and medical experiences of river dolphin management in captivity may aid such conservation efforts. The medical records and necropsy and histopathology reports on 123 captive Amazon River dolphins (Inia geoffrensis) were re-viewed. Of these 123 animals, 105 were necropsied and 70 necropsies were supported with histopathology. Eighteen animals were not necropsied. Among wild-born animals, mortality was highest in the first 2 mo immediately postcapture and transport, accounting for 32 of 123 deaths. Pneumonia and skin lesions (cutaneous and subcutaneous ulcerations and abscesses) were the most common findings, found in 44 of 105 (42%) and 38 of 105 (36%) of gross diagnoses, respectively. At least 10 of 44 cases of pneumonia diagnosed grossly included a verminous component. Cachexia, from a variety of causes, was a major gross finding in 21 animals. Fifteen animals had histologic evidence of significant renal pathology, and this was the primary cause of death in 13 cases. Hepatic pathology was found in 18 cases, and bacterial sepsis was confirmed via histology in 16 cases. Based on these findings, it may be concluded that keys to successful maintenance of this species include 1) prophylactic anthelminthic and antibiotic therapy immediately post-capture; 2) maintenance of animals in larger enclosures than in past attempts, in compatible groups, and in facilities capable of separating aggressive animals; 3) maintenance in microbiologically hygienic water quality at all times; and 4) a proactive program of preventive medicine during the immediate postcapture, quarantine, and maintenance period of captivity. 相似文献
52.
雏鸡的第1周的饲料数量仅是上市鸡总饲料的3.5%,但是为了得到最适的生长性能,环境的管理和恰当的营养是关键.因为雏鸡和成年鸡不一样,雏鸡没有复杂的消化酶,所以不能很好的起到消化的作用.在育雏期的早期,雏鸡面临着最困难的生理过渡时期,也就是开产期日粮中复杂的碳水化合物、蛋白质、脂类替代了胚胎中脂类和蛋白质的营养来源.而且雏鸡的免疫系统发育不完全,免疫主要靠母源抗体.…… 相似文献
53.
Francisco J. Escobedo David J. Nowak John E. Wagner Carmen Luz De la Maza Manuel Rodríguez Daniel E. Crane Jaime Hernndez 《Urban Forestry & Urban Greening》2006,4(3-4):105-114
Santiago, Chile's semi-arid climate and urbanized environment poses a severe limitation for the establishment and maintenance of urban forests. Municipalities, or comunas, are the main stakeholders in the management of Santiago's public urban forests. A tenable hypothesis would be that as the socioeconomic level of a comuna increases, the better the condition of a comuna's urban forest. Unfortunately, there is little comprehensive information on management, public expenditure, and structure of Santiago's public and private urban forests. To examine this hypothesis, Santiago was divided into socioeconomic strata, then using air photo interpretation and stratified field sampling, urban forest structures were quantified by socioeconomic strata. In addition, interview surveys were used to determine municipal urban forest management and expenditures for different public urban forests based on socioeconomic strata. Urban forests in the high socioeconomic strata had fewer public trees, greater tree cover, tree and leaf area density, and leaf area index than lower socioeconomic strata. The percentage of total municipal budget allocated to public urban forest management was consistent among strata, but the total public urban forest budgets were greater in the high socioeconomic strata. Public urban forest structure is related to the socioeconomic strata of Santiago's different comunas. 相似文献
54.
Potter Deborah U. Gosz James R. Molles Manuel C. Scuderi Louis A. 《Landscape Ecology》1998,13(4):203-214
Landscape Ecology - We investigated the question “Is there a relationship between seasonality in precipitation and vegetative cover in Pole Canyon, NM?” GIS and statistical methods were... 相似文献
55.
This paper presents empirical evidence on the impact of socio-economic factors on the adoption of agroforestry practices in
Cameroon. The analysis uses primary farm-level data collected from June to December 1996. Three major provinces of the country
were covered, namely Centre, Southwest and Northwest Several agroforestry technologies have been promoted among farmers in
the zone, including alley farming, improved fallow, live fencing, cut-and-carry fodder and apiculture. The status of adoption
of each agroforestry practice is described and factors that affect adoption identified. These are gender of farmer, household
family size, level of education, farmer’s experience, membership within farmers’ associations, contact with research and extension,
security of land tenure, agroecological zone, distance of the village from nearest town, village accessibility and income
from livestock. Research findings indicate that since factors affecting farmers’ adoption of agroforestry practices differ
across techniques, generalisation is to be avoided. 相似文献
56.
This study examines the strategies and benefits of the taungya farming system to both the government and the rural economy
in Nigeria. An interview survey was conducted in which data were collected from 115 randomly selected farmers in five villages
in the Oluwa forest reserve, Ondo State, Nigeria. The study examines the extent of participation of rural dwellers in plantation
development through taungya farming and the degree of success of this system as an afforestation method. The farmers were
predominantly illiterate, within the age bracket of 35–54 years and with small farm holdings. Twenty nine percent relied totally
on food from the forest reserve for their livelihood, while 71% also had farm holdings in free areas. Land within the reserve
is allocated to farmers free of charge but compensation is paid to landlords on land from free areas. A statistically significant
difference was detected in income from the two sources of farmland for the households and but not in the size of land allocated
under taungya and free areas. About 184 farmers are involved in taungya annually, and 410 ha of Tectonia grandis has been established for the government of Ondo State. 相似文献
57.
Catia Pereira Itziar Aurora Montalbán Olatz García-Mendiguren Tomás Goicoa Maria Dolores Ugarte Sandra Correia Jorge Manuel Canhoto Paloma Moncaleán 《Journal of Forest Research》2016,21(3):143-150
Pinus halepensis has been described as a drought-tolerant species with high plasticity to growth in different environments. Its eco-physiological characteristics could facilitate the use of this species in large afforestations in the future scenery of climate change. Somatic embryogenesis is a biotechnological tool with potential for large-scale clonal propagation. In order to establish an improved regeneration protocol for Pinus halepensis, the effects of different temperatures (18, 23, and 28 °C) and water availability conditions (2, 3, and 4 g L?1 Gelrite®), during initiation of embryonal masses on the rate of initiation, proliferation, maturation, and the number of embryos developed, were evaluated. It was found that environmental conditions during the initiation stage of Pinus halepensis somatic embryogenesis influence the success of initiation and proliferation. In contrast, there was no effect of these conditions on the maturation rates and the number of somatic embryos. Somatic embryos were obtained in all treatments tested, indicating that plants can be produced from extreme conditions of induction, such as high temperatures (28 °C) and low water availability conditions (4 g L?1). 相似文献
58.
Jorge Miguel Silva Faria Inês Sena Bruno Ribeiro Ana Margarida Rodrigues Carla Maria Nobre Maleita Isabel Abrantes Richard Bennett Manuel Mota Ana Cristina da Silva Figueiredo 《Journal of pest science》2016,89(1):207-217
The Columbia root-knot nematode (CRKN), Meloidogyne chitwoodi, is an EPPO A2 type quarantine pest since 1998. This nematode causes severe damage in economically important crops such as potato and tomato, making agricultural products unacceptable for the fresh market and food processing. Commonly used nematicidal synthetic chemicals are often environmentally unsafe. Essential oils (EOs) may constitute safer alternatives against RKN. EOs, isolated from 56 plant samples, were tested against CRKN hatching, in direct contact bioassays. Some of the most successful EOs were fractionated and the hydrocarbon molecules (HM) and oxygen-containing molecules (OCM) fractions tested separately. 24 EOs displayed very strong hatching inhibitions (≥90 %) at 2 µL mL?1 and were further tested at lower concentrations. Dysphaniaambrosioides, Filipendula ulmaria, Ruta graveolens, Satureja montana and Thymbra capitata EOs revealed the lowest EC50 values (<0.15 µL mL?1). The main compounds of these EOs, namely 2-undecanone, ascaridol, carvacrol, isoascaridol, methyl salicylate, p-cymene and/or γ-terpinene, were putatively considered responsible for CRKN hatching inhibition. S. montana and T. capitata OCM fractions showed hatching inhibitions higher than HM fractions. The comparison of EO and corresponding fractions EC50 values suggests interactions between OCM and HM fractions against CRKN hatching. These species EOs showed to be potential environmentally friendly CRKN hatching inhibitors; nonetheless, bioactivity should be considered globally, since its HM and OCM fractions may contribute, diversely, to the full anti-hatching activity. 相似文献
59.
We generated source-sink imbalances by defoliation and sucrose supplementation by stem injection, to investigate effects of carbohydrate availability on fruitlet growth and abscission in cv. Okitsu of Satsuma mandarins (Citrus unshiu (Mak.) Marc.). Partial defoliation promoted fruitlet abscission, whereas sucrose supplementation increased citrus fruit set by more than 10%. Moreover, when applied together, sucrose supplementation counteracted the effect of partial defoliation on fruit set. When sucrose was supplied continuously from flowering until harvest, it increased the concentrations of soluble and insoluble sugars in fruits. We conclude that fruit set in citrus is highly dependent on carbohydrate availability. 相似文献
60.
Effects of three forage harvesting regimes-total removal of foliage and branches once (T-12) or twice a year (T-6) and 50% removal every 2 months (P-2)-on growth and biological dinitrogen fixation of Gliricidia sepium (Jacq.) Walp were studied under subhumid tropical conditions in Guadeloupe, French Antilles. Gliricidia sepium was grown in association with the perennial C(4) grass Dichantium aristatum (Poir) C.E. Hubbard in a two-storied fodder production system. The medium-term effects of pruning on N(2) fixation were assessed by the (15)N natural abundance method. Gmelina arborea Roxb. was used as the non-fixing reference. The trees in the T-12 regime followed the natural phenological cycle, and flowering and podfilling at the beginning of the dry season reduced both foliage and nodule biomass. The T-6 regime impeded flowering, and only a few flowers, on older branches, were produced in the P-2 regime. In trees in the T-12, T-6, and P-2 regimes, fixed N comprised 54-87, 54-92, and 60-87%, respectively, of the total N in aboveground biomass, depending on sampling date. Total annual accumulation of N in harvestable aboveground biomass was highest in trees in the T-6 regime at 313 kg ha(-1), of which 204 kg ha(-1) of N was fixed from the atmosphere. In all treatments, about 70% of the N exported per year from the plot in the fodder harvest came from N(2) fixation. Thus, N(2) fixation makes an important contribution to the N economy of the G. sepium-D. aristatum forage production system, and greatly reduces the need for fertilizer application. 相似文献