汶川地震灾区辐射松覆盖保水造林试验研究

连续3a研究了不同覆盖保水方法对辐射松（Pinus radiate D．Don）造林及幼林生长的影响,结果表明：（1）塑料薄膜覆盖比对照造林保存率提高12．2个百分点、苗高生长量提高11．9cm、地径生长量提高0．57cm,石块覆盖比对照造林保存率提高12．2个百分点、苗高生长量提高9．3cm、地径生长量提高0．39cm。（2）塑料薄膜覆盖的幼树提早20d左右萌动、延迟15d左右停止生长,石块覆盖幼树提早10d左右萌动、延迟7d左右停止生长。     

闽楠不同规格容器苗营造幼林生长情况分析

以闽楠6种不同规格容器苗营造的试验林为对象,分析造林当年的幼林生长情况。结果表明:采用不同苗龄和规格的闽楠容器苗造林,对造林成活率的影响不显著,对造林当年地径和树高的影响极显著;其地径和树高随着时间的推迟呈现上升趋势,其中1~3 a的Ⅰ级容器苗造林后地径和树高均高于同苗龄Ⅱ级苗。3 aⅠ级苗的当年地径生长量最大,达5.86 mm,1 aⅡ级苗的地径增长倍数最高,高出原地径1.48倍;树高生长量、增长倍数均以1 aⅡ级苗为最高,达20.15 cm,高出原树高0.77倍。结合造林成活率、地径生长量、树高生长量进行综合评分,3 aⅠ级苗造林的综合评分最高,达0.7658;2 aⅠ级苗次之,得分为0.5905。因此,从生长指标方面分析,Ⅰ级苗造林效果普遍优于Ⅱ级苗,选用3 a闽楠容器苗中苗造林效果好。     

辐射松、马尾松、长叶松与晚松人工林的生长规律比较研究

对九峰试验林场的辐射松、马尾松、长叶松及晚松人工林生长规律的研究结果表明 :长叶松生长最慢 ,而不宜大面积发展 ;辐射松、马尾松与晚松均表现较好 ,且辐射松与晚松材积生长速率高于马尾松 ,至 2 2a后 ,辐射松材积的生长速率将超过晚松 ;辐射松 4a时胸径连年生长量最大 ( 1 85cm) ,树高速生期为 1 2～ 1 6a,材积速生期为 1 4～ 1 7a,数量成熟龄在 40a之后 ;马尾松 4a时胸径连年生长量达最大 ( 1 30cm) ,1 3a树高连年生长量达最大 ( 3 5 0m) ,材积连年生长量 2 8a最高 ( 0 0 1 60 1m3) ,数量成熟龄为 35～ 40a ;晚松胸径连年生长量在第 3年达最大 ( 1 85cm) ,平均生长量 9a时达最大 ( 1 0 8cm) ,树高速生期为 3～ 8a ,材积速生期为4～ 1 5a ,数量成熟龄为 2 5a。     

云南红豆杉实生与扦插人工幼林生长量的比较研究

通过对云南省马关县金城林场云南红豆杉实生苗和扦插苗营造的4年生幼林的生长量进行对比分析,结果表明:实生苗造林幼树的树高、地径、生物量干重指标都大于扦插苗造林的幼树,且表现出明显的生长优势;实生苗造林幼树的地径变异系数是扦插苗造林幼树地径变异系数的1.1倍;扦插苗造林幼树树高变异系数是实生苗造林幼树树高变异系数的2.8倍。     

杉木不同苗龄苗木造林效果分析

通过采用不同苗龄杉木苗木进行造林试验,结果表明:2年生苗造林具有较大生长优势,造林2年平均树高生长量为2.99 m,平均地径为4.74 cm,是1年生苗木造林树高生长量的1.73倍、地径生长量的1.80倍,存在着极显著差异;2年生苗造林2年生长量是1年生苗木造林3年平均树高、地径生长量的1.11倍和1.05倍。在郁闭成林投入成本对比上,2年生杉木苗造林每667 m~2投入成本为1 884元,比1年生苗林造林成本每667 m~2节约了124元。     

马大杂种相思无性系造林早期生长调查

通过对马大杂种相思无性系造林试验早期生长调查,结果表明:马大相思造林成活率较高,达98%;采用株行距为2.0 m×3.0 m的造林密度各项生长指标表现较好;从树高、冠幅、地径和干形4个生长指标数据来分析,1年生马大相思幼树无性系间生长存在个体差异,其中SK1和10#这2个无性系表现较好,不同生长期的树高、冠幅、地径和干形差异极显著,说明定植后植株的树高、冠幅、地径方面生长较快;马大相思与不同树种混交配置造林试验初步结论是,马大相思与桉树混交种植各项生长指标较接近,且能有效促进桉树生长,适合与桉树混交造林,其中以2:1的混交比例有利于树高和地径生长;马大相思与山杜英混交种植的各项生长指标差异巨大,不适合与山杜英混交造林;马大相思幼树的生长量是随着气温与降雨量增大而加快,其树高、地径与冠幅的生长高峰期出现于7月、8月、9月和10月,这4个月占全年生长量的70%左右,造林后可根据这变化规律加强抚育,能有效地提高林分的生长量。     

连续修枝对亚美马褂木生长及干形的影响

人工修枝是用材林无节良材培育的一项重要技术措施。本研究对亚美马褂木(Liriodendron sino-americanum)采用3种修枝处理,即分别修除占树高1/2、1/3、1/4处的下部枝条,连续3a对亚美马褂木3a生幼林进行修枝,每个生长季结束后测定,分析不同修枝强度对马褂木生长产生的影响。协方差分析结果显示:3次修枝后,1/3修枝强度下的树高生长显著优于1/2修枝处理及对照(未作任何修枝处理),在胸径生长上不同处理间及处理与对照间均无显著差异;在高径比上不同处理与对照差异不显著,但在胸径地径比上存在显著或极显著差异,1/3和1/4修枝处理具有较高的胸径地径比;从连续3a的观测结果来看,修除占树高1/4~1/3处的下部活枝,有利于促进亚美马褂木的生长,但过度修枝(≥1/2)对亚美马褂木生长有显著的抑制作用。     

岷江上游干旱河谷岷江柏木幼林地绿肥种植研究

在岷江上游干旱河谷岷江柏木幼林地经过连续4 a利用雨季种植绿肥压青,增加土壤肥力,提高水分利用率,促进幼树生长研究。结果表明:(1)种植红豆草的土壤0～40 cm含水量旱季增加3.68 g·kg-1,0～20 cm土壤容重降低0.07 g·cm-3;种植草木樨土壤0～40 cm含水量旱季增加4.18 g·kg-1,0～20 cm土壤容重降低0.05 g·cm-3;种植沙打旺土壤0～40 cm含水量增加2.46 g.kg-1,0～20 cm土壤容重降低0.18 g·cm-3。(2)种植绿肥压青,土壤有机质增加0.37 g·kg-1～0.55 g·kg-1,土壤CaCO3含量下降0.66 g·kg-1～1.36 g·kg-1,有效氮增加4.5 mg·kg-1～18.5 mg·kg-1,有效磷含量增加1.0～3.46 mg·kg-1,CEC比对照增加0.54～0.58mg.100g-1。(3)种植红豆草、草木樨、沙打旺绿肥压青对岷江柏木树高、地径生长有显著的促进作用,尤其种植红豆草的岷江柏木幼树生长最好,高、径生长为对照的1.7倍和1.6倍。     

干旱地带应用DBOL保水剂营造黄连木的试验研究

经过连续3 a利用DBOL保水剂对黄连木裸根苗造林及幼林生长的试验研究,结果表明:(1)黄连木裸根苗造林保存率提高10.5%～14.5%;(2)黄连木幼林高生长量增加41.3 cm～53.0 cm,地径生长量增加1.83 mm～2.05 mm;(3)黄连木幼树提早15 d左右萌动,延迟10 d左右停止生长。     

麻栎在郴州石漠化地区的栽培试验

研究了不同造林树种在石漠化地区的生长情况和不同海拔高度及土壤母质类型下麻栎的生长情况,结果表明：在郴州石漠化地区,麻栎-柏木混交林中麻栎的树高生长量(210.87～216.87 cm)及地径生长量(22.57～28.80 mm)大于柏木的树高生长量(148.60～188.60 cm)及地径生长量(20.00～22.24 mm);同样,麻栎-光皮树混交林中麻栎的树高生长量(244.83～250.47 cm)及地径生长量(30.34～34.40 mm)也大于光皮树的树高生长量(180.80～235.60 cm)及地径生长量(20.49～29.10 mm),从总体上看麻栎的生长情况表现显著优于柏木及光皮树,而后二者是郴州石漠化地区复绿造林的常用树种,这也表明麻栎适合于郴州石漠化地区的造林推广。另外,栎的树高和地径生长量受到海拔高度和土壤母质类型等立地条件的显著影响,表现为海拔高度越高生长量越小、石灰岩优于砂砾岩优于花岗岩,而对地径生长量的影响会弱于对树高生长量的影响。     

Restoration of the mangrove vegetation in the Mahanadi delta,Orissa, India

In India, mangroves occupy 6740 km² of which the Mahanadi delta andBhitarkanika mangrove forests of Orissa cover 191.44 km², most of whichhas been severely overexploited. World wide concern to conserve mangrovesnecessitated propagation of mangroves to re-establish them on barren andswampy land along tidal creeks around Paradeep port of Orissa. Avicenniaofficinalis, Aegiceras corniculatum, Bruguiera parviflora, B. sexangula,Ceriops decandra, Excoecaria agallocha, Heritiera fomes, Kandelia candel,Rhizophora mucronata, Sonneratia apetala were vegetatively propagated andplanted over 10 ha of degraded salt-marshy wetlands of Mahanadi delta inpure and mixed stands depending on the intensity and the frequency of tidalinundation at the experimental site. Survival was significantly higher(80%) in S. apetala followed by A. officinalis, R. mucronata, K.candel and H. fomes (70–75%). S. apetala recorded the maximumgrowth in height (3.0 m after 2 years) whereas C. decandra showed theminimum growth (0.5 m). Growth performance was better with plants in mixedstands than the plantation with single species. This gives us hope topropagate and re-establish mangroves for conservation in scientificallymanaged plantations in a physiologically arid environment.     

Sciences,knowledges, and the practice of forestry

We address the question of how credible knowledge that will contribute to more effective forest policy and management can be produced. We argue that some forest-related knowledge-producing practices of professional scientists and of local people are similar, and given the differences in the knowledge they produce, we explore how they might be used productively together to create better understandings of forests with resulting better forestry practice and policy. Using a case study of participatory forest ecology research, we demonstrate that when professional (conventional) scientists do research in collaboration with local experts (civil scientists), the resulting knowledge can be more accurate and more policy relevant than they could produce doing research on their own or only with other conventional scientists.     

Biodiversity,exotic plant species,and herbivory: The good,the bad,and the ungulate

Invasion of natural ecosystems by exotic plant species is a major threat to biodiversity. Disturbance to native plant communities, whether natural or management induced, is a primary factor contributing to successful invasion by exotic plant species. Herbivory by both wild and domestic ungulates exerts considerable impact on structure and composition of native plant communities. Intensive herbivory by ungulates can enhance exotic plant invasion, establishment, and spread for three reasons: (1) many exotic plants are adapted to ground disturbances such as those caused by ungulate feeding, trampling, and movements; (2) many exotic plants are adapted for easy transport from one area to another by ungulates via endozoochory and epizoochory; (3) many exotic plants are not palatable or are of low palatability to ungulates, and consequently, their survival is favored as ungulates reduce or eliminate palatable, native plants. Ungulate herbivory is a chronic, landscape-scale disturbance capable of influencing plant communities as much as episodic events such as fire. Consequently, ungulate herbivory has the potential to facilitate the invasion and establishment of exotic plants in the interior Pacific Northwest where ungulates occupy nearly every ecosystem. Moreover, ungulate herbivory has intensified in many ecosystems, owing to the addition of domestic ungulates with that of existing, wild ungulates, coupled with the reduction or elimination of migratory movements and predators that previously regulated wild ungulate populations and influenced their distributions. Despite the observational evidence for ungulate herbivory as a strong facilitator of exotic plant invasion and establishment, current knowledge of cause–effect relations is severely limited by a lack of manipulative experiments. Most studies have been observational, unreplicated, and lack the experimental controls needed to eliminate or account for confounding sources of variation. Heightened attention to conservation of biodiversity will increase the importance of managing ungulates in balance with the plant communities that support them.     

Diversity,abundance, and structure of tree communities in the Uluguru forests in the Morogoro region,Tanzania

Uluguru forests are globally recognized as important biodiversity hotspots, but anthropogenic pressure threatens their value. This study examined species diver-sity, abundance, and structure of trees i...     

大连市环境与社会、经济、人口、资源重心演变路径分析

采用重心法分析了大连市环境与社会、经济、人口、资源的空间变化规律,结果表明:大连市经济发展正向着高效能、低能耗、低排放的增长模式转变,环境治理日益得到重视,产生环境污染的能源结构仍然以煤炭为主,污染重心逐步远离经济重心和人口重心。各区市县在环保投资方面投入较均衡,废气污染减排取得成效,中心城区是环境污染排放和社会经济发展的高密度区域。     

三峡库区消落带土壤氮磷钾、pH值和有机质变化

在三峡库区消落带设置固定监测样地,研究消落带首次经历水库水位涨落后土壤氮磷钾含量、pH值和有机质含量的变化特征.结果表明:受三峡水库水位涨落影响,消落带0～10,10～20和20～30cm土层的速效氮含量下降41.53％～59.87％,速效磷含量下降5.26％～36.76％,速效钾含量下降3.55％～45.56％,全氮含量下降9.52％～40.00％,土壤有机质含量下降7.62％～37.83％,全磷和全钾含量基本上没有变化,土壤pH值略有变化,变幅为1.73％～9.58％.     

Endemism of plants in the Uluguru Mountains,Morogoro, Tanzania

A survey was conducted to determine richness of Vascular Endemic Plants of the Uluguru Mountains in Morogoro, Tanzania. Strict and near-endemic species were identified and their habits, habitats and altitudinal ranges were indicated. About 108 strict endemic plant species were identified in the Uluguru Mountains. Most of the endemic species are shrubs followed by herbs, trees and climbers, and are confined to the families Rubiaceae (38 species in 11 general), Orchidaceae (13 species in 7 general) and Balsaminaceae (11 species in 1 genus). The major habitat for endemic species is the montane rain forest on the windward side ranging between 1200 and 2450 m a.s.l. The major areas where the Uluguru endemics are concentrated are the forests of Bondwa/Lupanga followed by Lukwangule/Chenzema and then Bunduki and Mgeta. These areas are therefore the major hotspots for the endemism in the Uluguru Mountains. The information presented in this paper will contribute to the conservation and management of the biodiversity of the Uluguru Mountains.     

应用白僵菌防治靖远松叶蜂的研究

利用病原菌防治害虫是森林可持续发展的重要途径。本研究采用2003年4月从山西省灵丘县下关林区油松林内采集的越冬油松毛虫DendrolimustabulaeformisTsaietLiu幼虫的僵虫尸,经实验室分离、培养和鉴定后得到的白僵菌Beauveriabassiana菌株,用2×108孢子/mL、2×107孢子/mL和2×106孢子/mL3种浓度的孢子液对靖远松叶蜂DiprionjingyuanensisXiaoetZhang幼虫分别进行室内和林间感染,试验结果显示:室内感染4龄幼虫校正致死率分别为83.37%、78.82%、62.05%,LT50分别为5.794d、6.237d、7.603d;感染5龄幼虫校正死亡率分别为68.23%、59.1%、45.79%,LT50分别为7.244d、8.414d、12.274d;林间感染幼虫校正死亡率分别为65.26%、54.21%、38.23%,LT50分别为16.788d、19.187d、30.2d。结果表明靖远松叶蜂幼虫校正死亡率与白僵菌孢子液浓度呈正相关,与LT50呈负相关,与龄期呈负相关。     

Wolves, elk, willows, and trophic cascades in the upper Gallatin Range of Southwestern Montana, USA

We summarized the status of wolves (Canis lupus), elk (Cervis elaphus), and woody browse conditions during the 20th century for the upper Gallatin elk winter range in southwestern Montana, USA. During this period, wolves were present until about the mid-1920s, absent for seven decades, and then returned to the basin in 1996. A chronosequence of photographs, historical reports, and studies indicated willows (Salix spp.) along streams became heavily browsed and eventually suppressed following the removal of wolves, apparently due to unimpeded browsing by elk. However, after wolf establishment in 1996, browsing intensity on willows lessened in some areas and we hypothesized that, at both a landscape and fine scale, browsing pressure reflects terrain configurations influencing predation risk (nonlethal effects), in conjunction with lower elk densities (lethal effects). We measured browsing intensity and heights of Booth willow (S. boothii) along 3000 m reaches of the Gallatin River and a tributary to examine the potential influence of wolf/elk interactions upon willow growth. Where the Gallatin Valley is relatively narrow (high predation risk), willows began releasing in 1999 and by 2002 were relatively tall (150–250 cm). In contrast, willow heights along a wider portion of the Gallatin Valley, along the open landscape of the tributary, and an upland site (all low predation risk) generally remained low (<80 cm). We identified terrain and other features that may contribute to the perceived risk of wolf predation, by elk for a given site. Although alternative mechanisms are discussed, changes in willow communities over time following wolf removal and their subsequent reintroduction were consistent with a top-down trophic cascade model involving nonlethal and possibly lethal effects. If similar top-down effects upon vegetation hold true in other regions of North America and other parts of the world where wolves have been extirpated, wolf recovery may represent a management option for helping to restore riparian plant communities and conserve biodiversity.     

水,生命之源

尽管地球上70％的面积覆盖着水,但我们的蓝色星球依然干渴。据预测,到2025年世界将近一半的人口会生活在缺水的地区。中国人均水资源不到世界平均水平的1/4,水资源问题更为严峻。3月22日,“世界水日”和“中国水周”到来的时候,我们人类的生命之源——水将再度成为世人关注的焦点。