Patterns of forest use and endemism in resident bird communities of north-central Michoacán, Mexico

We compared breeding avian communities among 11 habitat types in north-central Michoacán, Mexico, to determine patterns of forest use by endemic and nonendemic resident species. Point counts of birds and vegetation measurements were conducted at 124 sampling localities from May through July, in 1994 and 1995. Six native forest types sampled were pine, pine–oak, oak–pine, oak, fir, and cloud forests; three habitat types were plantations of Eucalyptus, pine, and mixed species; and the remaining two habitats were shrublands and pastures. Pastures had lower bird-species richness and abundance than pine, oak–pine, and mixed-species plantations. Pine forests had greater bird abundance and species richness than oak forests and shrublands. Species richness and abundance of endemics were greatest in fir forests, followed by cloud forests. Bird abundance and richness significantly increased with greater tree-layer complexity, although sites with intermediate tree complexity also supported high abundances. When detrended correspondence-analysis scores were plotted for each site, bird species composition did not differ substantially among the four native oak-and-pine forest types, but cloud and fir forests, Eucalyptus plantations, and mixed-species plantations formed relatively distinct groups. Plantations supported a mixture of species found in native forests, shrublands, and pastures. Pastures and shrublands shared many species in common, varied greatly among sites in bird-species composition, and contained more species specific to these habitats than did forest types.     

杂柑天草在湘南地区引种嫁接试验初报

湘南地区引进杂柑天草接穗在尾张温州蜜柑树上进行高接换种研究发现:高接后第二年始果,第三年有一定产量;春季萌动始于3月上旬,3月中旬现蕾,4月中下旬盛花期,5月下旬至10月底为果实膨大期,果实成熟期在11月中下旬;果实平均单果重206 g;果实汁多味浓,可溶性固形物12.9%,100 g鲜果肉含维生素C 33.17 mg,可滴定酸0.53%;树势中等偏弱。     

不同生境油茶林油茶史氏叶蜂的发生与危害程度比较

通过比较不同生境油茶林区油茶史氏叶蜂幼虫危害程度、同一种生境距林边不同距离油茶史氏叶蜂的危害程度,分析了油茶史氏叶蜂对油茶春梢发育、夏梢发育、花芽分化率、花芽数目、落果率等的影响。结果表明:油茶史氏叶蜂对油茶的春梢发育、夏梢发育、花芽分化率、春梢上花芽数目、同期的落果率等有显著危害,且危害程度和林区的生态多样性相关;不同生境下,生态多样性越低,危害越严重;同一生境下,距混合林区距离越远,危害程度越重,说明保护油茶林区及周边生境的生态多样性,对防治和控制油茶史氏叶蜂是必要的。另外通过间接证据,提出了白头鹎Pycnonotus sinensis和伯劳Lanius schach等食虫鸟类是油茶史氏叶蜂幼虫重要捕食性天敌的初步结论。     

Can native vegetation recover after slash pine cultivation in the Brazilian Savanna?

There is a widespread view that forest plantations with exotic species are green deserts, unable to sustain biodiversity. Few studies have demonstrated, however, that planted stands of exotic trees have a greater negative effect on the plant diversity of savanna vegetation. We compared the native woody flora under four stands of slash pine of about 45 years old with four stands where the previously existing native Cerrado vegetation was preserved and protected from disturbances for the same period, has changed into dense vegetation - the “cerradão”, at Assis municipality, São Paulo State, Brazil. Aiming at understanding the potential ecological filters driving these communities, we assessed air and soil humidity, light availability and classified the native species on the basis of shade tolerance, dispersal syndrome and biomes in which they occur (Atlantic Forest or Cerrado). We recorded an average of 70 (±13) species under pine stands and 54 (±16) species in cerradão. Of the total of 136 species recorded, 78 occurred in both habitats, eight were exclusive to the “cerradão” (shade tolerant and also occurring in forest ecosystems) and 18 were recorded only under pine stands (82% heliophytic, exclusive to the Cerrado biome). Among the functional attributes and abiotic variables analyzed, only light availability explained the floristic differences found. Since richness was higher under pine, we refuted the hypothesis that exotic species constrain the establishment of the native species richness in the understory. On the other hand, the dark environment under the closed-canopy of the “cerradão” acts as a filter inhibiting the establishment of typical Cerrado species. Since pine stands, if managed in long cycle, maintain a reasonable pool of Cerrado endemic species in the understory pine plantations may be a good starting point for savanna restoration.     

Negative effect of removing pulp from unripe fleshy fruits: seed germination pattern of Celtis sinensis in relation to the temporal context of fruit consumption

We explored the temporal effects of fruit consumption on the subsequent seed germination pattern of a fleshy-fruited tree, the Chinese hackberry (Celtis sinensis). Via nursery-based sowing experiments, we investigated (1) how pulp removal affected seed germination patterns at the different stages of fruit maturation, and (2) how the timing of seed dispersal (August, October, and December) affected the germination patterns of seeds from ripe fruits after the removal of pulp. We found that the removal of pulp from around the seeds of ripe fruit had no effect on the percentage and timing of germination. In contrast, the removal of pulp from seeds of unripe fruits largely reduced the germination percentage. The time of sowing did not affect the germination percentage, whereas the timing of germination was delayed for seeds that were sown later or under shaded environments.     

华中五味子人工栽培条件下开花结果特性研究

通过对秦岭北坡野生华中五味子优良单株引种建园观察,揭示了栽培条件下其花器官组成、结构性状的变化、花芽的类型及在枝条上的分布特点、开花过程、物候期、结果枝的类型及开花结果能力、果实在果枝条上的分布等特性,为规模栽培提供了科学依据。     

Invertebrate abundance in different forest habitats as animal food available to capercaillie Tetrao urogallus chicks

Invertebrate abundance was estimated in 1981 and 1982 by sweep‐netting at twelve forest vegetation types in Vegårshei, Southern Norway. Invertebrates are expected to be a major determinant of habitat quality to gallinaceous birds, since animal food is considered essential to young chicks. The twelve fixed stations were chosen to illustrate poor and rich habitats and a gradient from bog to forest habitat. Rich vegetation types also had the highest abundance of invertebrates mainly due to moist and heavy soils. A comparison between a clear‐cutting and a similar vegetation type not logged, showed strong reduction in invertebrate availability after cutting. The influence of this alteration on availability of the capercaillie Tetrao urogallus chicks’ food is discussed.     

Growth and fruit production of the tree <Emphasis Type="Italic">Caryocar brasiliense</Emphasis> in the Cerrado of central Brazil

Caryocar brasiliense is a native tree found throughout the Cerrado savanna biome in central Brazil, and is exploited by rural population as food and industry. Although the abundance and popularity of this species in Cerrado have been an important component of local extractive economy, several aspects of sustainability as fruit production per tree size and growth rate have received little attention. We monitored, during two growing seasons, the stem growth rates and fruit production of tree in a wild population in Distrito Federal, central Brazil. The results showed a low growth rate of trees. The proportion of adult population fruiting was higher in 2006 than in 2007. For the smallest size (7.3-cm stem diameter) to begin fruiting, the estimated age was between 30 and 51 years old, and for tree with the largest stem diameter in the plot (43-cm diameter) the age was estimated to be between 110 and 153 years old. The whole fruit production by hectare was highly variable between years and was associated with differences in annual precipitation. The total fruit production was 1,004 fruits per ha (72.9 kg ha⁻¹) in 2006, and 299 fruits per ha (21.7 kg ha⁻¹) in 2007. The fruit production per tree was significantly positively correlated between 2006 and 2007 fruit season. Although an estimated fruit yield for whole Cerrado region is more than enough to support the actual demand, the slow growth rates and intensive harvesting indicates that more attention to sustainable management is required to avert demographic collapse of this cornerstone of the Cerrado extractive economy.     

胡柚花芽分化观察

用冰冻切片法观察胡柚花芽分化各阶段的形态特征．胡柚花芽分化从１２月中旬开始到次年４月中旬结束，可分为６个时期，历时１２０ｄ左右。花芽分化和物候期存在一定的相关性．刚进入盛果期的胡柚，其春梢结果母枝的各节位均能分化花芽，主要集中在其顶端的第１￣第４节位上．     

湖北沙湖湿地自然保护区秋季鸟类物种多样性

2006年10～11月期间,采用样线法对湖北仙桃沙湖湿地自然保护区4种生境中的鸟类进行调查.共记录到鸟类139种,隶属于14目31科,其中留鸟55种、夏候鸟31种、冬候鸟41种和旅鸟12种;古北种65种、东洋种49 种、广布种25种.分别采用Shannon-wieren指数、Pielou指数和G-F指数对保护区鸟类物种进行分析,结果显示鸟 类群落丰富度为芦苇>树林>水域>农田;对鸟类群落的相似性采用Jaccard指数进行分析,结果表明农田和树林的鸟类群落相似程度最高.     

泡核桃林昆虫群落结构及其摄食功能研究

采用灯诱法,于2021年4月上旬至6月中旬对泡核桃林昆虫群落结构及其摄食功能进行研究。共诱捕到昆虫2 968头,隶属13目63科172属187种,其中74种取食植物叶片,29种刺吸植物汁液,22种捕食其他昆虫,17种取食植物花、芽、果,10种取食腐烂物,12种钻蛀植物茎干,8种为地下昆虫,5种寄生其他昆虫,4种取食植物花蜜,3种取食苔藓,3种传授植物花粉,3种取食腐木,2种取食粪,隶属13个营养生态位集团。对泡核桃造成严重危害的昆虫有核桃星尺蛾、漫绿刺蛾、星天牛、梗天牛、绿凹缘花金龟、暗异花金龟。个体数量以鳞翅目最多,鞘翅目次之,螳螂目最少;物种数以鞘翅目最多,鳞翅目次之,螳螂目最少。核桃星尺蛾、粗狭肋鳃金龟、华锐紅蝽、黑翅土白蚁为优势物种。昆虫群落组成与泡核桃林物候关系密切,在泡核桃开花、结果的高峰期,昆虫群落呈较高的多样性、均匀度分布格局。在一定程度上,捕食与寄生昆虫控制了林内害虫;食粪与腐烂物、食腐木与苔藓昆虫分解了林内有机物,促进了生态系统的物质循环。     

夏秋季节水肥调控综合措施对油茶促花保果效果的影响

为了提高盛果期油茶林的产量,针对当前成林油茶落花落果率高而保花保果率低的问题,就不同的保墒、根外追施微肥与植物生长调节剂及冬季修剪等水肥调控综合技术措施对油茶保花保果效果的影响情况进行了试验研究。结果表明:(1)采用覆草、根外追施0.1 g/L的尿素与100 mg/L的GA3的坐果率最高;修剪与保水措施对坐果率的影响较大。(2)对油茶成林4月与7月保果率的影响最大的分别为修剪强度与保水措施,追施0.1g/L的硼肥有利于提高油茶4月与7月的保果率。(3)滴灌、喷施0.10 g/L的硼肥与100 mg/L的GA3及轻度修剪后油茶花芽分化数量最高;植物生长调节剂对油茶7月花芽分化的影响最大。     

The ecology of tree regeneration in mature and old forests: combined knowledge for sustainable forest management

We focused our attention on quantifying the factor complex of forest regeneration in 423 mature and old stands with contrasting environmental conditions. We recorded the microhabitat selection of tree recruits, the frequency of tree seedlings, and evaluated the drivers of sapling abundance and diversity. The majority of forest regeneration was established on undisturbed forest floor. Dead wood was a frequent substrate in spruce-(co)dominated forests. Seedling frequency within a stand was related to the site-type specific productivity gradient of stands—pine seedlings were common in low-productivity and spruce in high-productivity boreal forests. Seedlings of temperate broad-leaved trees dominated in productive boreonemoral forests, except for oak, which showed a uniform distribution of abundance in all forest site-types. Sapling abundance was dictated by forest site-type, and facilitated by stand diversity, variability in stand closure, lying dead wood, abundant moss, and a thick organic layer. Only in boreal forests was sapling abundance suppressed by the abundant spruce and younger trees. Upon considering the relationship between sapling abundance and species richness, sapling diversity was dependent on forest site-type, suppressed by stand density and dead wood (old gap) abundance, and facilitated by stand diversity. In addition, boreonemoral stands, competition from herbs, and facilitation by mosses occurred. The observed pattern of tree recruitment points to the importance of top-down effects of the overstory, competing or facilitating interactions with forest floor vegetation, and availability of regeneration microhabitats, which in complex make their ecology comparable with forest herbs. Natural forest regeneration can be enhanced if silvicultural methods support mixed stands and enhance field layer diversity. Oak can provide the universal tree species to improve stand structure over a wide range of habitats.     

Species-specific drought effects on flower and fruit production in a Mediterranean holm oak forest

A holm oak forest was exposed to an experimental drought (reductionof 15 per cent soil moisture as predicted for this area forthe next decades by General Circulation Models and ecophysiologicalmodels) during 7 years to elucidate the reproductive responsesof the dominant species Quercus ilex L., Arbutus unedo L. andPhillyrea latifolia L. Soil moisture was partially reduced byplastic strips intercepting rainfall and by ditch exclusionof water runoff. During the period studied, meteorological conditionsand soil moisture were continuously monitored, together withflower and fruit production in the three dominant species. InQ. ilex and A. unedo, flower and specially fruit productionwere strongly correlated with annual rainfall, but not in P.latifolia. The experimental drought reduced flower and fruitproduction in Q. ilex by 30 per cent and 45 per cent, respectively.Reductions in flower and fruit production were not significantin A. unedo and were not observed in P. latifolia. A decreasein production of reproductive structures and the different responseof the species studied to a decrease in water availability couldinduce important changes in the competitive ability of the differentspecies and in the long term in the community species compositionand future distribution of these Mediterranean species.     

海南霸王岭天然次生林边缘效应下木质藤本的变化

选择海南岛霸王岭天然恢复60年的次生林样地中形成年限为17和13年的边缘,分别设置4条10m×100m的样带,研究边缘效应对木质藤本多度、丰富度、胸高断面积、径级结构和攀援方式的影响。结果表明:8条样带中,记录木质藤本植物89种3252株;2种边缘中,木质藤本多度都随距边缘距离的增加显著降低,木质藤本胸高断面积未产生显著变化,木质藤本丰富度只在17年边缘中随距离增加而降低;在13年边缘中,随距边缘距离的增加,胸径大于1cm的木质藤本个体比例有所增加,而17年边缘中藤本的径级结构相对稳定;距边缘不同距离间,不同攀援方式木质藤本的个体比例存在显著差异,2种边缘中主茎缠绕类藤本均占优势。边缘效应对木质藤本群落结构的影响随距边缘距离的增加而减弱,影响深度随边缘形成年限的增加而增加,在17年边缘中影响深度为40～50m,在13年边缘中约为10m。     

Phenology and pollination of Manilkara zapota in forest and homegardens

Knowledge on reproductive phenology and pollination biology are basic elements that should be considered in the management and exploitation of plant species that offer non-timber products. The tropical tree Manilkara zapota is a species from which non-timber products have been obtained for centuries by Mayan communities in Mexico. Nevertheless, there are no quantitative reports on its reproductive biology and the factors that limit fruit production. The present study describes the reproductive phenology, breeding system and pollination of this species in two contrasting environments: medium-height, subdeciduous forest, and homegardens (“solares”) in a Mayan community in the state of Yucatan. Significant differences were found between environments both in the temporal distribution of flower and mature fruit production, as well as in the proportion of mature fruits. Homegarden trees showed the greatest fruit production, although flower production did not differ between environments. Mature fruits were of better quality (i.e., greater fresh weight) in homegardens. Hand pollination experiments showed that M. zapota is self-compatible, and that there is pollinator limitation for fruit production in trees that grow in homegardens. We propose that water and soil nutrients are the main factors limiting M. zapota fruit production in forests, while in homegardens the main factor appears to be pollinator availability.     

Abies religiosa forests harbor the highest species density and sporocarp productivity of wild edible mushrooms among five different vegetation types in a neotropical temperate forest region

More than 300 wild edible mushrooms are consumed in Mexico. They have been reported mainly from temperate forests in the center and southeast of the country. However, these valuable non-timber forest products are under-utilized because a lack of knowledge on their ecology and productivity. The objectives of this work were to compare the richness and fruit body production of wild edible mushrooms in temperate forests with a distinct vegetation composition in Amanalco, to describe species availability, and to test a new sampling approach in a heterogeneous environmental context. We designed a sampling method with random transects rather than traditional fixed sampling sites. Our method permits the acquisition of data from the highest number of environmental conditions. In 2009 and 2010, we collected and counted mushrooms in 248 transects distributed in five vegetation types (Abies, Abies–Pinus, Pinus, Pinus–Quercus and Quercus). We calculated the ecological importance value of each species as a function of its relative abundance and relative spatial frequency and relative temporal frequency. Abies religiosa pure stands and A. religiosa–Pinus forests had the greatest richness of edible fungi (43.1 and 21.3 species ha^?1, respectively) and produced most of the fruit bodies (1,160 and 820 ha^?1, respectively). The most abundant species in Amanalco region (combining all the vegetation types), Clavulina cinerea, Clitocybe gibba and Russula brevipes, also had the highest ecological importance value (0.2312, 0.1709 and 0.1516, respectively). These temperate forests maintain a considerable diversity of valuable wild edible mushrooms that are heterogeneously distributed according to the type of vegetation.     

Canopy vs. understory: Does tree diversity affect bee and wasp communities and their natural enemies across forest strata?

Bees and wasps provide important ecosystem services such as pollination and biocontrol in crop-dominated landscapes, but surprisingly little information is available on hymenopteran communities in temperate forest ecosystems. Species richness and abundance of bees and wasps can be hypothesised to increase with plant diversity, structural complexity, and availability of food and nesting resources. By experimentally exposing standardised nesting sites, we examined abundance and species richness of cavity-nesting bees (pollinators), wasps (predators) and their associated parasitoids across a tree diversity gradient in a temperate deciduous forest habitat. In addition, spatial distribution of individuals and species across forest strata (canopy vs. understory) was tested. Abundance and species richness was high for predatory wasps, but generally low for pollinators. Species-rich forest stands supported increased abundance, but not species richness, of pollinators and predatory wasps, and also increased abundance and species richness of natural enemies. In addition, the forests showed a distinct spatial stratification in that abundance of bees, wasps and parasitoids as well as parasitism rates were higher in the canopy than understory. We conclude that particularly the canopy in temperate forest stands can serve as an important habitat for predatory wasp species and natural enemies, but not bee pollinators. Enhanced tree diversity was related to increased hymenopteran abundance, which is likely to be linked to an increase in nesting and food resources in mixed forest stands.     

日本野漆树在梅州地区的引种表现

广东省梅州市从 2013 年开始引种日本野漆树（Toxicodendron succedaneum）并开展造林试验, 对该树种在梅州地区多年度的引种生长表现进行分析,以期为日本野漆树的种植应用提供指导作用。结 果表明：日本野漆树在梅州地区具有良好的适应性,栽培易成活,造林保存率高,达到 96% 以上。日本 野漆树生长迅速,栽种 7 年后树木平均树高、地径、冠幅分别达到 4.28 m、11.31 cm 、4.32 m;栽种 5 年 后进入初果期,栽种 7 年后进入全面挂果期,平均单株挂果量为 4.64 kg。物候观测显示日本野漆树在梅 州树木生长期达 250 天左右,其果实采收期为 9 月,比种植在湖南、江西的提早近一个月 , 比种植在日本 的提早 3 个月。果实性状分析显示日本野漆树单株间果实性状（漆果大小、种皮占果实的质量比、果实 含蜡率等）具有显著差异 (P<0.05),果皮含蜡率为 40%~60%,漆仔含蜡率为 21%~35%, 有必要对其进行 良种选育。同时方差分析显示引种对漆果性状（大小、种皮占果实质量比、漆果含蜡率）不会有显著改 变（P>0.05）。