Factors affecting the adoption of agroforestry practices by farmers in Cameroon

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.     

The impact of shade on morphology,growth and biomass allocation in <Emphasis Type="Italic">Picea sitchensis</Emphasis>, <Emphasis Type="Italic">Larix</Emphasis> × <Emphasis Type="Italic">eurolepis</Emphasis> and <Emphasis Type="Italic">Thuja plicata</Emphasis>

To determine the effect of shade on morphology, growth and biomass allocation in Picea sitchensis, Larix × eurolepis and Thuja plicata, seedlings were grown in the open or under shadehouses providing 25%, 50% and 75% reductions of full-light for two growing seasons. For most of the characteristics assessed there was no significant interaction between species and shade indicating that the morphological responses to changing shade treatments were not species-dependent. After two growing seasons the mean height increment for the three species was significantly greater in 25% (76.1 cm) and 50% shade (74.9 cm) than in the open (69.5 cm). Root collar diameter increment, shoot, root and total biomass declined significantly with increasing shade while the opposite was true for the height:diameter ratio. In both western red cedar and hybrid larch the shoot:root ratio was significantly greater in the shade while in Sitka spruce this characteristic was not influenced by shade. While all species had significantly greater specific shoot areas in 75% shade than in 0% shade, this trend was particularly pronounced in hybrid larch. In hybrid larch and western red cedar, the normalised specific projected shoot area increased significantly with increasing shade. The opposite trend was observed for Sitka spruce. We conclude that in the main the species studied demonstrated similar shade acclimation responses despite their reported differences in shade tolerance.     

Proteins in Norway spruce thermomechanical pulp

Two methods of cytochemical staining using Coomassie dye and Cu⁺-bicinchoninic acid, respectively, showed that there are proteins in thermomechanical pulp (TMP) of Norway spruce. Protein isolated from TMP was analyzed for amino acid composition. There was about twice the amount of acidic amino acid material compared with basic amino acids, and the presence of glucosamine indicated that the isolated polypeptides also contained glycoproteins. The presence of proteins in ray cells and fiber tracheids in TMP adds to the chemical heterogeneity of the structurally complex high-yield pulp.     

Rural livelihood benefits from participation in the taungya agroforestry system in Ondo State of Nigeria

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.     

A variance-covariance structure to take into account repeated measurements and heteroscedasticity in growth modeling

This study proposes a within-subject variance-covariance (VC) structure to take into account repeated measurements and heteroscedasticity in a context of growth modeling. The VC structure integrates a variance function and a continuous autoregressive covariance structure. It was tested on a nonlinear growth model parameterized with data from permanent sample plots. Using a stand-level approach, basal area growth was independently modeled for red spruce (Picea rubens Sarg.) and balsam fir [Abies balsamea (L.) Mill.] in mixed stands. For both species, the implementation of the VC structure significantly improved the maximum likelihood of the model. In both cases, it efficiently accounted for heteroscedasticity and autocorrelation, since the normalized residuals no longer exhibited departures from the assumptions of independent error terms with homogeneous variances. Moreover, compared with traditional nonlinear least squares (NLS) models, models parameterized with this VC structure may generate more accurate predictions when prior information is available. This case study demonstrates that the implementation of a VC structure may provide parameter estimates that are consistent with asymptotically unbiased variances in a context of nonlinear growth modeling using a stand-level approach. Since the variances are no longer biased, the hypothesis tests performed on the estimates are valid when the number of observations is large.     

Newly recorded species of the genus Isohypsibius （Tardigrada; Hypsibiidae） from China

This paper reports two newly recorded species, lsohypsibius lunulatus Iharos, 1966 and lsohypsibiusprosostomus Thulin, 1928, of the genus lsohypsibius （Tardigrada; Hypsibiidae） from China. The specimens of lsohysibius lunulatus were collected from Taibai Mt （34°18′N, 107°42′E） at 2,500 m a.s.1, and those oflsohypsibius prosostomus from Taibai Mt （34°10′N, 107°35′E） at 2,000 m above sea level. All specimens are deposited at the College of Life Sciences, Shaanxi Normal University, China. A key to the Chinese species of lsohypsibius was also given.     

Dielectric properties of copper-ethanolamine treated Chinese fir (Cunninghamia lanceolata Hook.)

In order to clarify the interaction between copper and wood substances in wood treated with copper containing water-borne wood preservatives, the dielectric constant ε′ and dielectric loss factor ε″ of untreated wood and wood treated with four concentration levels of copper-ethanolamine (Cu-EA) solutions were determined within a temperature range from –100 to 40°C and a frequency range from 100 to 1 MHz. Three dielectric relaxation processes were observed in the ε″ spectrum; among them R-I is based on the reorientation of methylol groups in the amorphous region of wood cell walls and R-II is related to wood extractives. R-III appeared in Cu-EA treated wood, and its magnitude decreases with the concentration of Cu-EA solutions used in this experiment. This relaxation process was considered to be based on the reorientation of copper-ethanolamine-wood complexes in wood cell walls. At low copper retention, the hydrogen in the complex can form hydrogen bonding with adjacent hydroxyl groups, which results in a strong bonding state between copper and wood; at high copper retention, the numerous copper-ethanolamine complexes not only hinder them from forming hydrogen bonding with adjacent wood molecules due to steric hindrance, but also weaken the interaction between wood molecules themselves, which corresponds to reducing ε″ values of both R-I and R-III processes. The results explain the fact of in-creasing copper leaching in wood treated with high concentration copper-based water-borne preservatives.     

哈茨木霉天冬氨酸蛋白酶基因SA76的3＇RACE扩增和序列分析

由EST获得全长cDNA对于结构基因组学和功能基因组学都是至关重要的,cDNA末端快速扩增技术RACE是该领域中的重要研究方法.利用BD SMART RACE技术扩增编码分泌天冬氨酸蛋白酶SA76基因的3＇末端,将其与哈茨木霉cDNA文库中的SA76基因的EST序列进行序列拼接,获得2019bp的全长cDNA序列,其开放读码框长1593bp,5＇非编码区266bp,3＇非编码区201bp,编码530个氨基酸,有信号肽.哈茨木霉天冬氨酸蛋白酶基因与玉蜀黍赤霉、粗糙脉孢菌、球毛壳菌天冬氨酸蛋白酶基因的同源性分别为53%, 37%, 36%.利用BD SMART RACE技术首次从哈茨木霉中克隆天冬氨酸蛋白酶基因,为验证SA76基因的功能奠定基础,为进一步研究蛋白酶的作用机制及生物防治功能提供依据.     

Socio-economic significance of reed forests in a rural community: A case study from the greater Sylhet Region of Bangladesh

The reed forests that are the subject of this study are scattered over five thanas of the Sunamganj and Sylhet Districts of the Sylhet Division of Bangladesh. Their total area is 23,590 ha and they have great ecological, economic, commercial and socio-economic importance due to the diversified resources they supply. However, the forests are commonly encroached on by local people who are perceived to be seriously depleting the resource. This paper deals with the socio-economic status of the people residing near these reed forests, and examines their dependency on the resources provided by the reed forests. A socio-economic survey, participatory rural appraisal and interviews were used to obtain baseline data of the reed forest resource and the local communities. The study reveals that the communities in the study region have higher income than other areas of Bangladesh. Most survey respondents have other occupations in addition to farming. The literacy rate is 28.8%. Among the illiterate, 68% engage in collecting reeds. Although the Forest Department has a management plan for sustainable use of the reed forests, encroachers receive backing from political leaders and local elites, so their eviction is difficult. In order to achieve long-term productivity and sustainability from the reed forests, this study recommends a strategy of developing an integrated joint management plan between the Forest Department and the local people.     

The use of compensatory and non-compensatory multi-criteria analysis for small-scale forestry

Small-scale farm forestry has the potential to offer many benefits both to landholders and the wider community. As with all changes in land-use practices, there are associated benefits and costs and these are not uniformly distributed. They have varying impacts on the different values, aspirations, goals and objectives that exist within the community. Furthermore, the community does not consider these values, aspirations, goals and objectives of equal importance. The degree of concern can vary from minor to high and overriding all other considerations. When evaluating farm forestry options it is necessary to address all of these concerns. This paper examines the combined use compensatory and non-compensatory multi-criteria analyses to evaluate forestry options, in a case study for the Darling Downs region of Queensland, Australia. These aggregation techniques are found to be highly complementary and together provide a comprehensive analysis. The compensatory technique provides a sound measure of overall performance of a forestry system, whereas the non-compensatory technique alerts decision-makers to presence of particularly poor performance with respect to individual criteria. The compensatory technique used is simple and understandable even for those with non-mathematical backgrounds. This analysis can identify and aid communication of the relative benefits and costs, and trade-offs, between economic, environmental and social considerations.