云南山地民族刀耕火种生态学定位与山地森林资源可持续利用

通过对云南省永仁县直苴村刀耕火种农业的景观生态学研究，发现在一个相当长的时期内，正是刀耕火种使山地民族社区人和森林都实现了自身的可持续发展，并同时实现了二者的和谐发展，但随着人口、资源和环境的变化，刀耕火种存在的条件不断消失，刀耕火种也必然消失，这说明任何一种物质生产方式都有其时空尺度的局限性，都必须以一定的环境条件和资源条件为基础，以区域内生态系统的健康、持续性发展为前提，     

Pruning of néré trees (Parkia biglobosa (Jacq.) Benth.) on the farmlands of Burkina Faso, West Africa

This study of the pruning of néré (Parking biglobosa) trees in central Burkina Faso included detailed surveys of 83 trees and their owners in 21 villages. Pruning is not widespread, but appears to be a practice with various motives and techniques. The motives are mainly aimed at deliberate management of the trees, in order to enhance their fruit production, and are rarely aimed at reducing tree impact on crop productivity. The characteristics of tree pruning techniques (e.g., frequency, intensity and seasonality) and their corresponding motives appear to change as an adaptation to land degradation processes and the deterioration of tree condition. The results demonstrate that indigenous silvicultural management techniques contribute to a sustainable use of tree resources.

---

Résumé Cette étude sur la taille du néré (Parkia biglobosa) a été faite par des observations détaillées de 80 nérés et les entretiens avec leurs propriétaires dans 21 villages au Plateau Central du Burkina Faso. La taille du néré n'est pas générale, mais révèle diverses motivations et techniques. La plupart des motivations est orientée vers une gestion consciente de l'arbre en vue d'une amélioration de la production furitière, et rerament en vue d'une reduction de l'influence de l'arbre sur les cultures. Les caracteristiques des techniques de taille (fréquence, intensité, période de taille) et les motivations impliquées paraissent s'adapter à la dégradation de l'environnement et al détérioration de la viabilité des arbres. Les résultats montrent la durabilité des pratiques concernant la gestion des arbres.

     

Plant diversity of secondary forests in response to anthropogenic disturbance levels in montane regions of northeastern China

The effects of anthropogenic disturbances on forest structure and plant diversity of secondary forest ecosystems were evaluated based on the classification by site factors in the montane regions of northeastern China. Forty-five sample plots containing 720 sub-plots of overstory species (8 m × 8 m), 1,440 quadrats of understory species (2 m × 2 m), and 1,440 quadrats of herbaceous layer species (1 m × 1 m) were clustered into five groups (G1, G2, G3, G4 and G5) by site variables with Hierarchical Cluster Analysis. Meanwhile, the disturbance levels corresponding to the five groups were determined according to the factors influencing human disturbances (D0-G2, D1-G1, D2-G3, D3-G5, and D4-G4). Species diversities of overstory, understory, herbaceous layer and overall species were evaluated using species number, Margalef index, Pielou index, Shannon–Wiener index, and Simpson index; and β-diversities (Whittaker index, Cody index). Basal area of stands exhibited a decreasing trend along the disturbance level due to a gradual increase in the extraction of timber by the human disturbances. The indices of species diversity suggested that overstory and understory species were distributed evenly among the groups or disturbance levels. There were no absolutely dominant tree species in the secondary forest ecosystems. The differences in site factors and the current disturbance intensities were not intense enough to lead to loose changes in overstory and understory species. The species diversity indices exhibited the maximum values at D3 (G5) for herbaceous layer species; this may suggest that the current disturbance intensities were intense enough to lead the changes of herbaceous layer species. Three rare and endangered species (Juglans mandshurica, Fraxinus mandshurica and Acanthopanax senticosus) were found within the secondary forests. These rare and endangered species appeared in each clustered group or disturbance level, which suggested that the current disturbance intensity in the study area was not strong enough to influence the distribution of rare and endangered species. The current disturbances in the secondary forests may not lead to a decrease in stability and complexity of the overstory and understory species, but the higher disturbance level may be intense enough to change the habitat fitness for the herbaceous species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized authors.     

沿淮稻茬麦区小麦的产量及籽粒灌浆特性

为给沿淮稻茬麦区小麦高产栽培及品种育种提供依据,在大田条件下,选取沿淮麦区6个高产小麦品种为供试材料,用三次多项式方程对籽粒灌浆过程进行拟合,通过相关性分析对小麦籽粒灌浆参数与粒重的关系进行探究,研究不同小麦品种间产量及其构成因素的差异。结果表明： 6个品种中,安农大1216的产量最高,为8 598.77 kg·hm^-²,烟农19最低,产量为6 031.07 kg·hm^-²;籽粒灌浆过程中安农大1216粒重最高,成熟期千粒重达到51.4 g,郑麦9023的千粒重最低,为47.78 g;各个品种间灌浆速率存在明显差异。不同小麦品种籽粒灌浆过程均呈“S”型变化,因品种不同,灌浆参数也有所不同,但“R²”均达到0.99以上。相关性分析表明,千粒重与理论最大粒重（W）显著相关,与平均灌浆速率（V）、最大灌浆速率（V_max）、有效灌浆持续期平均灌浆速率（Vs）、有效灌浆持续期粒重增加值（Ws）和最大灌浆速率出现时间（T）呈正相关但未达显著水平。可见筛选的W、V、V_max、Vs、Ws和T等灌浆参数值较高的小麦品种在该地区种植有利于提高小麦千粒重,增加产量。此外,必须考虑到小麦品种、高效栽培方式、管理手段和协调产量构成三因素,才会最大可能实现小麦高产高效。     

模糊综合评价法判断重庆花椒种植区土壤肥力水平

为揭示重庆花椒地土壤质量状况及空间特征,采集重庆主要花椒区45个土壤样品,测定pH值、容重、有机质、有效磷、碱解氮、速效钾、有效铜、有效锌、有效铁、有效锰、有效硼、有效钼、有效硫共13个指标,采用模糊综合评价法对土壤质量进行综合评价,并利用半变异函数分析各指标空间变异特征。结果表明:各养分指标变异系数范围为14.8%～171.4%,该区域养分含量分布很不均衡;有效磷、有效铁、有效硼、有效硫的空间相关性较弱,主要受随机性因素影响;有效锌和有效铁的隶属度最高,其值分别为0.89、0.91,有效硼和有机质的隶属度较低,其值为0.15、0.34,说明花椒地有效锌和有效铁含量较丰富,但有效铁和有机质含量较缺乏;整体上该区中等肥力水平占51.1%,中等偏上肥力水平占42.2%,中等偏下肥力水平占6.7%,土壤肥力综合指数的在空间上呈现球状半变异函数,拟合程度极高。     

边疆民族地区贫困县城乡一体化发展研究--以昌宁县田园镇为例

指出了随着城镇化的快速推进,城乡统筹发展理论与实践越来越受到关注,城乡一体化将成为城乡发展的基本趋势。边疆民族地区贫困县城乡一体化受到自然环境、区域经济、民众意识和社会政策等制约,迫切需要优化动力机制和构建发展模式。提出了田园镇在推进城乡一体化战略过程中,应依托“蝶形”空间格局,以经济发展为主导,推广内力培育与外力推动并重路径。在实践中,应立足发展目标一体化,循序进渐地开展产业与空间布局一体化,加强生态环境保护与基础建设一体化。     

欠发达地区农业产业化龙头企业问题研究——基于甘肃省358家企业的调查

龙头企业对西部欠发达地区农业产业化进程及农业经济增长具有重要意义。文章通过对甘肃省358家农业产业化龙头企业的调查分析,发现龙头企业在发展过程中存在企业家文化素质偏低、技术人才短缺、自主研发能力弱、产品竞争力不强等问题。在此基础上从战略管理、利益联结、科技创新以及政策环境等方面就如何发展壮大欠发达地区龙头企业进行了一定程度的思考。     

Rainfall erosivity and erosivity density through rainfall synthetic series for São Paulo State,Brazil: Assessment,regionalization and modeling

Rainfall is the main cause of erosion of Brazilian soils, which makes assessing the rainfall erosivity factor (RE) and the erosivity density (ED) fundamental for soil and water conservation. Therefore, the objectives of this study were: i) to estimate the RE and ED for São Paulo State, Brazil, using synthetic series of pluviographic data; ii) to define homogeneous regions regarding rainfall erosivity; and iii) to generate regression models for rainfall erosivity estimates in each of the homogeneous regions. Synthetic series of pluviographic data were initially obtained on a sub-daily scale from the daily rainfall records of 696 rainfall gauges. The RE values were then estimated from the synthetic rainfall data, and ED was calculated from the relationship between erosivity and rainfall amounts. Monthly and annual maps for RE and ED were obtained. Hierarchical clustering analysis was used to define homogeneous regions in terms of rainfall erosivity, and regionalized regression models for estimating RE were generated. The results demonstrate high spatial variability of RE in São Paulo, where the highest annual values were observed in the coastal region. December to March concentrate approximately 60% of the intra-annual erosivity. The highest values of annual ED were observed in regions with intense agricultural activity. The definition of five homogeneous regions concerning the rainfall erosive potential evidenced distinct seasonal patterns of the spatial distribution of erosivity. Finally, the high predictive accuracy of the regionalized models obtained characterizes them as essential tools for reliable estimates of rainfall erosivity, and contribute to better soil conservation planning.     

城乡转型背景下林区劳动力非农就业影响因素分析——以福建省三明市为例

农民就业是我国面临的重大经济与社会问题。在人多地少等多种因素下,农业自身无法吸纳我国庞大的农村剩余劳动力,只有实现向非农产业的转移,才能逐步解决农村剩余劳动力的就业问题。利用福建省三明市的12个村84户农民的样本数据,通过Logistic回归模型对影响林区劳动力非农就业的因素进行了分析。结果表明,有劳动力外出务工的农户占76.2%。随着林农受教育程度的提高,林农对身份转变的认识显著提高,非农就业意愿明显增强。家庭人数越多,小孩越少,劳动力流动率就越高。人均林地面积越丰富,林业对劳动力的粘性就越强,林农外出务工的意愿下降。务农收入和农村非农产业收入是农户决定其成员是否流动所参考的重要依据。重视微观层次的户主禀赋、家庭特征、林地禀赋和收入差异,对于促进林区劳动力外出务工具有重要意义。     

少数民族自治区可持续发展能力综合评价——以贵州省少数民族自治县为例

为了研究我国少数民族自治地方的可持续发展能力,以贵州省为例,运用因子分析法,通过构建可持续发展能力指标体系,对其11个少数民族自治县的可持续发展能力进行了综合评价:同时运用聚类分析法,对各县的经济可持续发展能力、社会可持续发展能力、生态可持续发展能力以及可持续发展综合能力了进行空间聚类,并就增强少数民族地区的可持续发展能力提出了相应的建议.