甘孜藏族自治州草地类别及高山草地的利用

甘孜州有可利用草地１７．９１ｋｍ＾２，地势高，起伏大，气候，土壤，植被垂直变化明显，依据气候－土地－植被“综合顺序法”分类系统可分为１５个类。其中“寒温潮湿类”和“寒冷潮湿类”高山草地面积大，分布广，是最重要的草地畜牧业区域，但冷暖季饲草供应极不平衡，在保护和利用方面存在一些问题，应改进畜牧业经营方式，加强对草地的保护和合理利用，以提高生产水平。     

A fractal model of vegetation complexity in Alaska

A methodology using fractals to measure vegetation complexity in three regions of Alaska is presented. Subjective, binomial (0 = simple, 1 = complex) classifications of the complexity of mapped vegetation polygon patterns within continuous forest inventory plots measured in the regions were made by interpreters of aerial photographs. The fractal dimensions of the vegetation patterns within the plots then were estimated. Subsequently, the subjective classifications of the photo-interpreted plots were regressed against fractal dimension by using logistic regression.Assessment of interobserver agreement among the aerial photo interpreters, by using estimated unweighted Kappa coefficients, indicated substantial classification agreement among observers.Examination of general versus regional applicability of the logistic models provided strong support for applicability of a single model to all three regions. The logistic model provides numerical identification of the division between simple and complex patterns. Possible applications beyond the needs of the study are discussed.     

猪链球菌2型JX分离株的生物学特性

从临床表现为脑膜炎、关节炎及败血症的发病猪分离到2株细菌，分别命名为JX02和JX03，经鉴定其形态、染色及培养特性均符合链球菌的特点，具α或β溶血，生化试验结果不稳定。用猪链球菌2型、1型和9型抗血清进行凝集试验，结果2株菌均能与猪链球2型抗血清凝集，其中1株菌对小鼠和家兔均有致病性，另1株菌只能致死家兔。PCR均能扩增2株菌的主要毒力因子基因。表明发病猪的病原不同于以往的C群链球菌，不是马链球菌兽疫亚种，而是属于R群的猪链球菌。     

Infectious bovine keratoconjunctivitis: Bacteriologic,immunologic, and clinical responses of cattle to experimental exposure with Moraxella bovis

The bacteriologic, immunologic, and clinical responses of 3- to 4-month old Holstein-Friesian calves to experimental exposure with Moraxella bovis type 10900 has been investigated. After u.v. radiation and intraconjunctival exposure with 1.9 × 10⁷ microorganisms, each eye of 16 calves exhibited signs of blepharospasm, photophobia, and increased lacrimation. Bacteria were recovered from exposed eyes for 2–7 consecutive weeks before maximal clinical response occurred. The severity of the cases varied from eyes that exhibited mild signs to severe clinical cases with profuse lacrimation, conjunctival swelling, corneal opacity, and ulceration. By 70 days after exposure, M. bovis could not be recovered from any conjunctival swabs, and clinical signs were not observed. Four non-exposed control animals did not develop clinical signs nor was M. bovis recovered from conjunctival swabs.Lacrimal secretions collected at the time of and 1 week after maximal clinical response had significantly elevated levels of total protein as compared to those collected 3, 2, and 1 week before, and 2 and 3 weeks after maximal clinical response. A passive hemagglutination test, using tanned formalized sheep erythrocytes sensitized with M. bovis sonicate antigen, detected antibody in lacrimal secretions from 22 of 32 eyes. The appearance of specific antibody in lacrimal secretions correlated with the amelioration of clinical signs and the decline in numbers of M. bovis microorganisms recovered from conjunctival swabs.     

冬虫夏草研究进展

冬虫夏草研究进展罗信昌（华中农业大学武汉４３００７０）冬虫夏草（Ｃｏｒｄｙｃｅｐｓｓｉｎｅｎｓｉｓ）是一种名贵的药用真菌，有多种药理功能，具有抗癌活性物质。我国是发现和在医药上应用冬虫夏草最早的国家，随后，欧洲及世界其他各国才开始对这类真菌标本的采集...     

关于水土保持与市场经济的几点思考

关于水土保持与市场经济的几点思考陈来如（安徽省安庆市水电局，２４６００３）（一）传统观念的水土资源远离市场１．水土资源的长期无偿使用，导致资源破坏、浪费严重。多年来，除政策失误外，经济活动中人们一直认为水、上等环境资源是大自然的恩赐，可以免费使用而无...     

Further data to the aetiology, pathogenesis and therapy of infectious bovine keratoconjunctivitis

Out of a total of 224 bovine eye secretions, 126 Moraxella bovis and 64 Neisseria ovis strains were isolated. The pathogenesis and histological lesions caused by Neisseria ovis have been studied on the eyes of three calves naturally affected with IBK, using electron microscopy.

Neisseria ovis caused in 1–12 weeks old calves acute, transient and mostly benign serous conjunctivitis with only slight affection of the cornea. More rarely erosions and even ulceration of the cornea have been observed.

Moraxella bovis and Neisseria ovis strains proved nearly unanimously sensitive in vitro to chloramphenicol, neomycin, oxytetracyclin, nitrofurantoin, erythromycin and cefoperazone. Other antibiotics and chemotherapeutics inhibited the growth of these agents only partly or were ineffective.

Experimental therapy has been carried out using a single i.m. injection of Terramycin/LA inj. (Pfizer) in a dose of 20 mg/kg body mass, repeated if necessary after 72–96 h. This formulation proved more effective and practical than treatments used earlier.     

江西省毛竹栽培区划及立地类型划分的研究

毛竹是江西省重要的经济树种,全省现有毛竹林面积793.7万亩,蓄积95737万根,毛竹生产在全省的林业生产中占有相当重要的地位。本文遵照自然规律和经济规律,以气候、地形和土壤等自然因子为主要依据,同时参照毛竹原有分布数量及社会经济状况,把江西省划分为5个毛竹栽培区。并根据立地因子的差异,应用逐步回归分析方法,寻求出主导因子,把江西省毛竹栽培区内划分出27个不同的立地类型。     

Land Cover Type and Fire in Portugal: Do Fires Burn Land Cover Selectively?

The purpose of this study is to investigate if, or under what conditions, fires select given land cover types for burning. If fires burn unselectively then the land cover composition (the proportional area of various land cover types) of individual fires should approximate the land cover composition available in their neighborhood. In this study we test this hypothesis by performing statistical analyses of a data set consisting of paired vectors with the proportions of land cover types present in burned areas and in their respective surroundings. The statistical methods employed (a permutation technique and the C_max statistic) are commonly used in resource selection studies where data is subject to a unit-sum constraint. The results of the analysis of 506 fires that burned in Portugal in 1991 indicate that fires are selective, with small fires exhibiting stronger land cover preferences than large fires. According to the results of a multiple comparison analysis performed for small fires, there is a marked preference for shrubland followed by other forest cover types, while agriculture is clearly avoided. A similar analysis is performed to test if fire selectivity is related to the ecological region where it occurs. The results obtained in this study contribute to the discussion on the relative importance of fuels as a drivers of fire spread.     

“撒、矮、荪”配套模式制种技术研究——Ⅱ、理想株型的定向培育

本研究探讨了通过培育理想株型以克服母本撒播制种潜在的倒伏危机的技术途径。该文表述了3个主攻要素的集合:1.培育庞大、高活力的根系群,改善耕层土壤结构,提高稻株固着力。2.培育矮壮、竖立、紧凑型植株,保持良好的光合姿态,降低重心,提高稳定性能。3.应用生化调控手段,使之既解除包颈,又不使植株伸长超高。其技术途径可归纳为:起垄栽培、节水勘灌;适时、适量喷施植物生长调节剂多效唑(MET)、九二○(GA3)。它们之间促进与制约的交互作用,成功地实现了理想株型的塑造。