研究生教育人力资本投资的制度导向

作为知识经济时代重要投资项目,研究生教育人力资本投资得到全社会越来越多的关注和重视。本文基于目前我国研究生教育工作中存在的问题,结合国内外研究生教育的发展趋势,提出改善研究生教育人力资本投资条件、提高研究生教育绩效的相关制度建议,为推动我国研究生教育事业的发展提供了参考和借鉴。     

知识图谱技术及其在农业领域应用研究进展

随着农业大数据时代的到来,如何开展直观的有效信息挖掘成为数据利用的一大难题。作为一种能够帮助人们高效地管理现实世界中事物及其关系的异构语义网络,知识图谱应用在近年来备受关注。在农业数据不断增加、结构越来越复杂的背景下,将知识图谱应用于农业领域有助于农业大数据分析,促进智慧农业发展。该文首先分析了知识图谱构建的模式,即自顶向下、自底向上及两种模式结合等3种模式的特点,然后从本体构建、知识抽取、知识融合、知识推理、知识图谱存储及可视化5个方面综述了农业知识图谱构建的关键技术应用进展与难点,接着对当前知识图谱在农业领域的应用进行了梳理,主要有农业专题文献计量研究、农业信息检索、农业知识问答和农业信息资源推荐等4个方面,最后对知识图谱技术在农业领域的应用研究方向进行了展望,认为未来应关注基于知识图谱的农产品电商推荐、动态农业知识图谱的构建、跨领域知识图谱的构建与关联等方面。     

The good shepherd: remedying the fencing syndrome

In this paper the use of fenced grazing camps to manage the rangeland commons is challenged. A historical perspective is presented on fencing and rotational grazing in South Africa. Two case studies in KwaZulu-Natal and the Northern Cape illustrate the factors that influence the management of rangelands under communal land tenure without the use of fences. It is argued that herding is preferred over fencing. The reintroduction of herding could reap multiple benefits such as improving rural livelihoods, reviving customary practice, reducing stock theft, reducing predation and improving biodiversity management. The paper concludes with some issues for consideration when implementing herding as a multipurpose strategy for improved rural livelihoods and sustainable management of natural resources.     

Comparison of production systems for efficient use of indigenous pig breeds in developing countries

Conserving pig genetic resources and improving their productivity is important to increase returns over investment in developing countries. The purebred, first‐cross, rotational cross and backcross matings representing production systems based on pig breeds indigenous to the country and exotic pig breeds were investigated. The number of pigs in the nucleus and commercial herds necessary to produce a defined quantity of pork was considered. The amount of heterosis between the indigenous and exotic breeds, superiority in meat production, and degree of inferiority in reproductive performance of the exotic breed compared with that of the indigenous breed were investigated. The number of breeding pigs in the whole system was in the following order: pure breeding (PB) > first‐cross (F1) > rotational cross (RC) > backcross (BC) systems. The number of breeding pigs in the nucleus herds of the RC and BC systems was smaller than that in the nucleus herds of the PB and F1 systems. The degree of inferiority in reproductive performance of the exotic breed compared with that of the indigenous breed affected the efficiency of the production system.     

Monitoring Growth Trials

The forestry industry predominantly depends on privately-owned forests which are foreign-owned, capital intensive and export oriented. The man-made forests cover 102 000 ha, about 6% of the total area of Swaziland. The two largest plantations, Usutu and Peak Timbers, account for 71% of the total plantation area in the Kingdom.

Pines and eucalypts are the two main genera planted for pulp, mining timber, sawtimber and droppers. There are nine companies engaged in the processing of wood into various products.

The land classified as marginal in Swaziland on account of low rainfall (less than 600 mm) occurs in low-veld, with characteristic tree species like Acacia nigrescens (umkhaya), Acacia tortilis (sitfwetfwe) and a fruit tree Sclerocarya caffra (umganu). In this region, plantation agriculture of citrus trees and sugar cane is only possible under irrigation. In terms of low inherent soil fertility in the highveld, plantation forests are grown on acidic granite and gneiss and also on land whose average gradient is more than 15%. Biotically induced marginal land occurs because of man and his activities: overstocking of livestock, uncontrolled burning of the veld during the dry winter, inadequate soil husbandry, increase in demand for various forest products and infrastructural development.

Low rainfall between 1974 and 1976 killed Eucalyptus grandis and Pinus taeda and reduced the growth rate of Pinus patula. Most of the forest sites in Swaziland are marginal land on account of granite and gneiss-derived soils of low pH, i.e., 4,5 to 5. Between 1981 and 1982, 27 t of different fertilisers were used in order to achieve an MAI of at least 17 m³/ha/a of utilisable material for Pinus patula on a 22 year rotation.

Usutu Forest and Peak Timbers Plantations have progressively contributed to the economy of Swaziland since the 1940s. In 1978, forest plantations and forestry oriented industries contributed about 24% of the total export earnings. During 1980, 95% of the unbleached kraft pulp was sold outside Southern Africa, while 3,1% of the total forest products was consumed in Swaziland. The forest plantations have improved the general infrastructure, including roads and educational and recreational facilities in the areas where they occur.

Resettlement schemes have also been undertaken among the displaced people.

The interest of the Swaziland Government lies chiefly in regulation and control of the forest sector, to optimise the existing resources to the benefit of the Swazi people, mainly for economic use of the land and water resources and encouraging national participation, at both wage employment and management levels, as well as implementing forest legislation.

Plantation forest activities have, however, several disadvantages to be cited: They are land extensive and therefore tend to encroach on land used for communal grazing and hunting, bee collecting and firewood and fruit gathering, all of which are difficult to quantify in monetary terms. The Euro-American philosophy of replacing open communal land with fenced boundaries marked by cairns, with penalties on contravention, cannot be readily accepted.

The forest product needs for the rural community come from the Swazi Nation Land, covering 65% of the total area of Swaziland. The biotic factors have much reduced the original area of vegetation cover which has resulted in the use of non-conventional material like cow dung, maize stalks, leaves of Aloe marlothii (inhlaba) and tall grass for fuel. The commercial forests are located far from the population centres, thus making transportation of the forest waste an uneconomic venture.

The Forestry Section, under the Ministry of Agriculture and Co-operatives, is working in close co-operation with the Rural Development Area (R.D.A.) programme to raise the general standard of living in the rural areas by establishing woodlots. In the current five-year National Development Plan, the Government plans to establish 13 000 ha of woodlots, carry out an indigenous forest inventory, implement forest legislation and train forestry personnel at all levels.

With the assistance of R.D.A. Project Managers, the donga-ridden areas on the biotically induced marginal land are fenced off and then planted with suitable tree species.

Black wattle, Acacia mearnsii, introduced in Swaziland at the beginning of this century, is predomminantly used for bark production. It covers 5 000 ha on Swazi Nation Land and 2 500 ha on Title Deed Land. Lack of proper management of black wattle has turned it into “jungles” in the Highveld, where land is not used for agricultural production. The yield of wet wattle bark is low on Title Deed Land, i.e. 15 to 20 t/ha. The bark is marketed on a basic bark quota system managed by a wattle growers committee of Pietermaritzburg. Wattle growers of Swaziland have now formed a cooperative to enable them to transport the bark economically.

The spread of black wattle has checked the formation of dongas in biotically induced marginal areas, but at the same time there is a general resentment among the rural community who believe it is eating up their grazing land. The public believe also that eucalypts are responsible for the drying up of streams and encouraging lightning in the rural areas.

Indigenous Acacia species are drought resistant, more favoured as fuelwood, but their MAI is very low and their seed is very difficult to collect and extract. Even when using exotic tree species in establishing woodlots, proper provenances are not easy to obtain.

Agro-forestry is being undertaken particularly in RDA's where individual farmers get tree seedlings from the forestry nurseries and plant them among agricultural crops.     

社会林业概述

概述了社会林业产生的历史背景和定义,并评述了社会林业的作用和研究的主要领域。在此基础上,提出了对社会林业研究的几点建议。     

名师是这样炼成的——以江阴市两所中职校市级名教师以上对象为例

本文以江阴市两所中等职业学校市级名教师为对象,通过问卷调查,分析了他们在成 长过程中的内因和外因,提出了中职校名师成长过程中的内因是:目标明确、自身努力、学问思 辨、终身学习、勇于实践,学校支持、名师引领等则名师成长的外因。     

Participatory research approaches to integrating scientific and farmer knowledge of soil to meet multiple objectives in the English East Midlands

Soil management influences food production, economic performance of farm businesses, and a range of public benefits such as water quality, flood control and aquatic and terrestrial biodiversity. The aim of this paper is to explore the role of participatory research in combining scientific and farmer knowledge of soils to meet these multiple objectives. We use five separate research studies involving communication, consultation and co‐production, carried out in the English East Midlands between 2014 and 2018. We compare the participatory processes for knowledge exchange and their material outcomes and assess them retrospectively against specified criteria for successful application of participatory research. We conclude that, depending on context and scalar fit, multiple approaches to participatory research can be complementary, strengthen engagement and build trust within a farming community, resulting in a greater shared understanding of how to address the soil management objectives of farmers and wider society.     

广东主要乡土阔叶树种单木生物量生长模型

【目的】选择广东主要乡土阔叶树种樟树Cinnamomum camphora、木荷Schima superba和枫香Liquidambarformosana为研究对象,建立3个树种的单木生物量生长模型,快速精确计量和监测森林碳汇造林项目的碳储量变化。【方法】每个树种按10个径阶均匀分配伐倒90株样木(共270株),以样木的生物量数据为单木生物量,以立木年龄为自变量,分别建立不同起源(天然林和人工林) 3个树种的地上和地下4种方程生物量生长模型,并选择最优模型通过联立方程组总量控制法解决地上各组分(干材、树皮、树枝、树叶)的生长模型相容性问题。【结果】天然林和人工林起源条件下,相同树种在同一生物量生长模型形式下生物量增长的上限值和最大增速年龄均有差异。各方程在相同起源和树种条件下所得的生物量上限和拐点年龄差异明显。估计地上生物量时,各树种最优方程形式不同。选择Logistic方程对3个树种地上各组分生物量联立方程组建立相容性生长模型,3个树种干材生物量方程的R_(adj)~2为0.560～0.768,平均预估误差(MPE)为3.05%～6.73%;树皮生物量方程的R_(adj)~2为0.552～0.866,MPE为2.02%～6.27%;树枝生物量方程的R_(adj)~2为0.309～0.706,MPE为3.01%～14.33%;树叶生物量方程的R_(adj)~2为0.495～0.767,MPE为4.16%～7.14%。【结论】比较4种模型的参数及评价指标可知,地上生物量生长最优模型为Logistic方程,地下生物量生长最优模型为Schumacher方程。地上各组分生物量在立木生长的周期中占地上总生物量的比例随着年龄的增长而不断变化。选择Logistic方程对3个树种地上各组分生物量联立方程组建立相容性生长模型,干材和树皮的生物量方程拟合效果相对于树枝和树叶更好。该模型主要适用于在已知年龄的人工碳汇造林的生物量估计;结合含碳系数,可预估未来一定时期内的碳储量及碳汇量。