不同管理枣林枣粘虫(Ancylis sativa)天敌功能团的组成及动态

枣粘虫(Ancylis sativa)是枣树主要的食叶和蛀果害虫,为了控制其危害,2004年在太谷地区对4种不同处理枣林的枣粘虫天敌发生与态势进行了系统的调查研究,结果表明种草综合防治枣林枣粘虫天敌昆虫的物种数比种草常规防治枣林、未种草综合防治枣林和未种草常规防治枣林分别增加37.2%、84.4%和118.5不%,个体数分别增加39.2%、91.0%和187.4%,枣粘虫幼虫和蛹的寄生率分别增加46.94%和31.27%、35.21%和21.99%、116.42%和60.33%;综合防治枣林区草蛉类和寄生性天敌类的丰盛度明显大于(P<0.05)化学防治的枣林,而瓢虫类与蜘蛛类则明显小于(P<0.05)化学防治的枣林,食虫蝽类与其它捕食性天敌则是种草枣林区大于未种草枣林区;枣林种草后天敌的恢复与重建速率提高了50%~81%;种草枣林多样性的标准误明显减小,相关性测定表明枣粘虫天敌功能团与物种的优势度、多样性、均匀度的变化趋势较为一致,均极显著(P<001)相关。     

啄木鸟科内谱系生物地理学新探

啄木鸟群体共包含254种,但早期对啄木鸟的分类学研究局限于形态学、行为学和鸣唱法等方向,分子研究结果又彼此存在差异,因此啄木鸟分类系统目前还有争议。分子数据的大量累积为啄木鸟系统发育的研究提供了条件。利用从GenBank获取的ND2基因序列,对啄木鸟科179种啄木鸟采用NJ法、MP法以及ML法分别进行了分子进化树构建,同时用NJ法重建了Picumnus属分子进化树。此外又利用cytb基因序列采用NJ法对Dryobates属和Picoides属进行分子进化树重建。我们的结果显示,姬啄木亚科Picumnus属新大陆物种彼此的进化关系仍需进一步研究,而该属唯一一种旧大陆种P.innominatus,种内遗传差异在种间水平依然显著,这说明其种内遗传差异一直被低估了。在啄木鸟亚科内,Hemicircus属和Nesoctites属为姐妹关系,而Geocolaptes olivaceus插入了Campethera属支系中,并非与其构成姐妹群体。此外,一些姐妹群在新旧大陆上的分布,推测这种分布可能与第四纪冰川有关。啄木鸟从旧大陆向新大陆迁移,在第四纪冰川作用下不断发生分布范围的扩张与收缩,最终形成现存的分布格局。     

新疆东天山微孢衣属地衣2个中国新记录种

对采自新疆东天山米泉林场的地衣鉴定分析,发现2个中国新记录种,即散点微孢衣(Acarospora dispersa H.Magn.)和暗灰微孢衣(A.obnubila H.Magn.)。根据研究标本描述了2个新记录种的形态解剖、化学特征和生境,并提供了相关形态学及解剖学彩色图片。标本保存于新疆大学西北干旱地衣研究中心的标本室(XJUNALH)。     

木榄幼苗对淹水胁迫的生长和生理反应

在搭建于广西英罗湾红树林外裸滩的试验平台上设置8个海面高程组,研究全日潮海区潮汐淹水胁迫对木榄(Bruguiera gymnorrhiza)幼苗的生长和生理影响.幼苗立地基质平面的海面高程为320～390 cm,相邻高程组相差10 cm,幼苗培养时间为1 a.结果表明:小高程和大高程处理均促进木榄幼苗茎高度的增长,中等高程则起抑制作用;中等高程组幼苗茎节数稍少;叶数、叶面积与叶保存率均随淹水程度加大而急剧下降;小高程生境对叶片叶绿素含量的促进作用较微弱,而大高程生境更有利于叶绿素含量上升;但较长时间的淹水胁迫使叶绿素a/b比值反而较高;小高程处理均促使叶片和根系中超氧物歧化酶(SOD)和过氧化物酶(POD)酶活性增强,同一高程组的木榄幼苗根系中超氧物歧化酶和过氧化物酶酶活性均高于叶片的数倍;较大高程生境更有利于木榄幼苗生物量累积,尤其是叶生物量,同时随着淹水程度的加大,新生器官中生物量分配比例由叶向茎转移;所有高程组均有一些幼苗死亡,海面高程越小幼苗存活率越低,由73.6%下降到35.0%.综合考虑,建议北部湾海区木榄胚轴造林的宜林临界线高程不低于当地平均海面以上21 cm.     

林业活动对区域森林生物量碳源汇格局的影响——以南平市为例

林业活动在一定程度上影响着区域森林的时空分布格局和碳汇/源功能。明确并量化林业活动对区域森林碳汇功能的影响与空间分布,对于区域森林碳汇提升和实现区域"碳中和"具有重要意义。以国家级生态示范区福建省南平市为例,以多期森林资源规划调查数据为基础,采用IPCC材积源-生物量法,基于土地利用类型的时空变化和林业活动类型划分,分类分析了南平市森林碳源和碳汇的空间分布特征,并量化了不同林业活动（一直保持为森林、人工造林、自然恢复、毁林和森林退化）对森林碳汇和碳源的影响。研究结果表明,2013年南平市森林碳储量总量为80.84Tg C,2020年森林碳储量总量增加至89.87Tg C,年均变化量为1.29Tg C/a （或4.73Tg CO₂/a）。平均胸径、公顷蓄积等林分因子是当前主要影响森林碳储量的因素。在其他影响因素中,暗红壤分布区的森林生物质碳密度较高而在水稻土分布区则较低;此外,高海拔、中等立地质量土地上的森林碳密度较高。对于不同林业活动,2013-2020年南平市一直保持为森林（森林经营）、自然恢复增加的天然林和人工造林分别使森林生物质碳储量增加了0.34Tg C/a、0.85Tg C/a和1.05Tg C/a,同期因毁林和森林退化导致森林生物质碳储量分别减少0.75Tg C/a和0.42Tg C/a,森林生物质碳储量净增加1.09Tg C/a （或3.98Tg CO₂/a）,明显低于2013-2020森林碳储量净增量。对于土地利用变化较剧烈的区域,本文基于土地利用变化且区分林业活动路径的方法,能更准确地反映森林的碳汇和碳源及时空格局。2013-2020年间南平市一直保持为森林的生物质碳密度仅增长0.22Mg C hm^-2 a^-1,成熟林、过熟林面积占比增加使森林平均生长速率下降可能是主要原因。而同期通过自然恢复和人工造林使森林生物质碳密度分别增长4.00Mg C hm^-2 a^-1和4.10Mg C hm^-2 a^-1。优化龄组结构提升森林生长量、减少毁林和防止森林退化可以作为该区域未来森林增汇减排的有效举措。     

Review: Application of biotechnology to forestry – molecular biology of conifers

Genetic improvement in plantation forestry relies significantly on conventional breeding techniques which have been used extensively to improve various characteristics in forest trees such as growth and form, volume yield, resistance to pathogens and quality of the end product. This review concentrates on molecular techniques which have been used successfully in agriculture and which have more recently become available to improve further characteristics of forest trees and introduce new traits which are currently not available in the breeding population.     

Mycorrhizae and their potential use in the agricultural and forestry industries

Mycorrhizal fungi associated with plant roots increase the absorption of nutrients, particularly phosphorus, and thus enhance the growth of crop plants and trees. Vesicular-arbuscular mycorrhizae (VAM) occur in approximately 90% of all vascular plants including most of the important agricultural species, whereas ectomycorrhizae are found in most of the economically important tree species of the temperate regions of the world, and in some tropical trees. These symbiotic associations are, therefore, important in crop and biomass production. For this reason they are receiving considerable attention in agriculture and forestry. Currently, VAM are utilized in fumigated soils, greenhouse crops, and in the reclamation of disturbed sites. Ectomycorrhizae are employed in the establishment of trees in nurseries, in reforestation programs, and in the production of containerized seedlings. Production of VAM and ectomycorrhiza inoculum for large scale projects is now feasible but many basic questions related to persistence of these fungi in field situations, competition with other microorganisms, and particularly the most efficient fungi to use for particular hosts remain largely unanswered.     

Hair,serum, and urine chromium concentrations in former employees of the leather tanning industry

In this study, we measured concentrations of Cr in hair, serum, and urine of men who were previously employed in the leather tanning industry. Concentrations of Cr in hair and serum were significantly lower than corresponding values obtained during their employment and were comparable to levels obtained for controls in a previous study. These results suggest that Cr III accumulated from employment in the leather tanning industry does not result in longterm elevation of Cr concentrations in the body     

Dynamics of cuticular chemical profiles of Polistes dominulus workers in orphaned nests (Hymenoptera, Vespidae)

We analysed changes in cuticular hydrocarbon signatures of workers in orphaned colonies of the paper wasp Polistes dominulus. In natural conditions, workers and foundresses possess characteristic cuticular signatures, and foundresses are further distinguishable, both behaviourally and chemically, on the basis of their rank in a reproductive dominance hierarchy. In our study, several workers were found to develop their ovaries and produce cuticular signatures resembling those of dominant foundresses, while remaining workers possessed undeveloped ovaries and had cuticular blends characteristic of subordinate foundresses. Workers that did not develop their ovaries had changed epicuticular signatures, demonstrating that the mixture of hydrocarbons of worker individuals is strongly dependent on social role and environment. Our results suggest that the composition of epicuticular lipids is not determined at the pre-imaginal stage, and that physiological pathways leading to cuticular chemical changes are similar in foundresses and workers of P. dominulus.     

Influence of larvae and workers on egg production of queens of the pharaoh's ant,Monomorium pharaonis (L.)

Summary Social regulation of egg production and weight in queens was studied in relation to presence and absence of larvae and workers in the pharaoh's ant,Monomorium pharaonis (L.).Results were obtained by counting eggs and weighing queens under various conditions.The results confirm the existence of a positive feed-back loop between mated queens and their larvae as evident from a correlation (Y = 4.575 * X + 6.452) between the number of large worker larvae (X) and the egg yield (Y). This correlation seems to relate to the queens preferential feeding on larval secretions. Queens without larvae maintained a low level of egg production of about 6 eggs/day. Queens deprived of larvae as well as workers stopped producing eggs within 24 hours.Repletes, special workers, with greatly distended gasters functioned as a buffer retarding decline of egg production by feeding the queens during short periods without larvae.