3种棕榈藤叶片叶绿素荧光特征分析研究

棕榈藤作为热带、亚热带植物中重要的森林资源,优质的藤材是重要的加工利用材料,具有重要的经济价值。叶片光合能力对藤材的形成具有重要影响,利用叶绿素荧光仪测定黄藤(Daemonorops jenkinsiana)、大白藤(Calamus faberii)、小白藤(C.balansaeanus)的叶绿素荧光参数,为研究逆境条件下棕榈藤的光合能力和选择适宜的栽培条件提供参考。结果表明,在实验室条件下3种棕榈藤的光系统Ⅰ(PSⅠ)实际光量子效率Y(Ⅰ)为小白藤 > 大白藤 > 黄藤,光系统Ⅱ(PSⅡ)的Y(Ⅱ)为大白藤 > 黄藤 > 小白藤;非光化学猝灭系数qN由高到低依次为大白藤、黄藤和小白藤;而光化学猝灭系数qP则是小白藤最高,黄藤次之,大白藤最低;PSⅠ的电子传递效率ETR(Ⅰ)是小白藤 > 大白藤 > 黄藤,而PSⅡ的ETR(Ⅱ)值则是小白藤 > 黄藤 > 大白藤;PSⅡ最大光量子产量F_v/F_m维持在0.78~0.8范围内,且大白藤显著高于黄藤和小白藤(P < 0.05)。由此可见,在实验室条件下小白藤的光合效率在这3种藤中最高,其次为黄藤,大白藤最低;且光保护能力为大白藤最高,黄藤次之,小白藤最低。     

A functional analysis of streamside habitat use by southern Appalachian salamanders: Implications for riparian forest management

The appropriate management of streamside forests and use of riparian strips is poorly resolved for many systems because of a lack of understanding of the extent to which riparian forests function as environmental buffers for aquatic species versus core (essential) habitat for semi-aquatic and terrestrial species. We studied streamside forests in western North Carolina and eastern Tennessee, USA, to help delineate their functional value for plethodontid salamanders. We established 30 m × 40 m plots at 17 sites (823–1716 m in elevation) in unmanaged forests with closed canopies. Plots contained a portion of a seep or first-order stream along one edge and typically extended 36–38 m into the adjoining forest. We examined use of stream and streamside habitats based on captures during area-constrained searches of cover objects. We observed 6423 plethodontid salamanders belonging to 7 terrestrial-breeding and 12 aquatic-breeding species. Terrestrial-breeders (primarily Plethodon spp.) comprised 37% of terrestrial specimens and were more abundant at higher elevations. Aquatic-breeders (primarily Desmognathus spp.) increased their proportionate use of terrestrial habitat, but declined in overall abundance with elevation. Catches of aquatic-breeders were greatest within 8 m of aquatic habitats (49% of total terrestrial catch of aquatic-breeders), particularly at low elevation sites. The terrestrial zone provided core habitat for one terrestrial-breeder (D. wrighti) and six semi-aquatic species (Desmognathus spp., Gyrinophilus porphyriticus and Eurycea wilderae) that were broadly distributed throughout plots, and acted as an aquatic buffer for four highly aquatic species (Desmognathus spp.). The remaining species were terrestrial-breeders (Plethodon spp.) that were evenly distributed across plots, suggesting that riparian strips would function as important source populations for recolonization following timbering on adjoining land. Because of the vulnerability of plethodontid salamanders to edge effects, effective management of southern Appalachian streamside habitats may require the addition of a terrestrial buffer to protect terrestrial core habitat that immediately adjoins streams and seeps.     

Population structure of Carapa guianensis in two forest types in the southwestern Brazilian Amazon

Carapa guianensis Aublet. is a tropical tree with strong multiple-use characteristics, and is valued for both the high quality oil extracted from its seeds and as a timber resource. This study compares the population structure of this economically important rainforest tree in two contrasting forest types: occasionally inundated and terra firme forests. Main study objectives were (a) to assess the density, spatial distribution, and size class structure of C. guianensis in these two forest types and (b) to use patterns of abundance, distribution and demographic structure to help infer key demographic stages or ecological variables that merit special focus for management. Four 400 m × 400 m plots, two in each forest type, were established to determine distribution and density patterns of C. guianensis ≥10 cm diameter at breast height (dbh) at the landscape level, and 32 10 m × 10 m subplots were randomly nested within each of the larger plots to measure individuals <10 cm dbh. Larger individuals (≥10 cm dbh) were found at higher densities in occasionally inundated forest than in terra firme forest: 25.7 trees ha⁻¹ and 14.6 trees ha⁻¹, respectively. Mean density of C. guianensis individuals <10 cm dbh was also higher in occasionally inundated forests, but variation of regeneration density among the subplots was high. Spatial distribution methods revealed a tendency toward clumping in both forest types, and both had similar size class structures, suggesting that both environments are suitable for C. guianensis. This new finding illustrates the potential for C. guianensis management in terra firme forests. High densities and clumped distributions in both forest types are also indices favorable for sustainable species management. Finally, several ecological variables (tree density and reproductive potential) were sufficiently different between terra firme and occasionally inundated forests to recommend stratification by forest type when conducting further studies on key ecological and management variables of C. guianensis.     

棕榈藤的研究和发展

棕榈藤是热带和南亚热带森林宝库中的多用途植物资源 ,原藤是仅次于木材和竹材的重要林产品 ,具有重要的经济价值。本文概述了国内外棕榈藤物种资源天然分布及其利用状况 ;比较全面地介绍了国内外棕榈藤的研究和发展的历史与现状 ,并提出了今后的研究和发展方向     

The site specific variables that correlate with the distribution of the Pacific Golden Chanterelle, Cantharellus formosus

Cantharellus formosus is one of the most abundantly collected commercial mushrooms in western North America. Despite its importance to commercial harvesting, little information is known about the habitat requirements of C. formosus. The purpose of this study was to identify the environmental factors that correlate with the distribution of the basidiomata of C. formosus. Fifty-five plots (5 m × 5 m) with basidiomata and 60 comparison plots without basidiomata (5 m × 5 m) were established in Sitka spruce stands in Patrick’s Point State Park. Thirty plots with basidiomata and 30 without basidiomata were randomly selected for measurement of all variables. The latter included total percent cover of the following categories: shrubs, forbs, bryophytes and canopy cover. Diameter at breast height (DBH), height of trees, and other factors were also measured including duff depth, exchangeable cations, exchangeable acidity and aluminum, pH, and organic matter. Data were analyzed using logistic regression analysis to determine which environmental variables significantly correlated to the distribution of basidiomata. The Chi-squared test of homogeneity was used to determine if presence of chanterelle basidiomata was related to soil classification characterisitcs. The results indicate that chanterelles are associated with areas with low exchangeable acidity (2.09 ± 0.30 cmol+/kg soil), moderate duff depth (11.01 ± 0.45 cm), and areas with bare humus and needle cover less than 30% (29.05 ± 3.04%). Identification of these variables is important to assist land managers in identifying habitats where C. formosus basidiomata are likely to occur.     

Forest vegetation of Xishuangbanna, south China

1 Introduction The tropical area of southern China is climatically and biogeographically located at the northern edge of tropical Asia, including southeastern Xizang (Tibet, lower valleys of the southern Himalayas), southern Yunnan, southwestern Guangxi, southern Taiwan and Hainan Island. The largest tropical area still covered by forests is in southern Yunnan. Tropical forests of southern Yunnan were little known until the late 1950s because of poor access except for some brief descrip-…     

White spruce regeneration following a major spruce beetle outbreak in forests on the Kenai Peninsula, Alaska

Between 1987 and 2000, a spruce beetle (Dendroctonus rufipennis) outbreak infested 1.19 million ha of spruce (Picea spp.) forests in Alaska, killing most of the large diameter trees. We evaluated whether these forests would recover to their pre-outbreak density, and determined the site conditions on which spruce germinated and survived following the spruce beetle outbreak in forests of the Anchor River watershed, Kenai Peninsula, Alaska. White spruce (Picea glauca) and Lutz's spruce (Picea × lutzii), a hybrid between white and Sitka spruce (Picea sitchensis), dominate the study area. We measured the pre- and post-outbreak density of spruce in 108 3 m × 80 m plots across the study area by recording all live trees and all dead trees >1.5 m tall in each plot. To determine the fine scale site conditions on which spruce germinated and survived, we measured ground surface and substrate characteristics within 20 cm circular plots around a subset of post-outbreak spruce seedlings. The density of post-outbreak spruce (855/ha) was adequate to restock the stands to their pre-outbreak densities (643/ha) for trees >1.5 m tall. We could not accurately estimate recovery for pre-outbreak spruce seedlings because dead seedlings may have decayed in the 5–18 years since the beetle outbreak occurred. At the fine scale, spruce that germinated post-outbreak grew on a wide variety of substrates including downed log, stump, mesic organic mat, peat, hummocks and mineral soil. They exhibited a strong preference for downed logs (53%) and stumps (4%), and most (91%) of the downed logs and stumps that spruce rooted on were heavily decayed. This preference for heavily decayed logs and stumps was especially evident given that their combined mean cover was only 2% in the 3 m × 80 m plots. Within the 3 m × 80 m plots, spruce seedling survival was negatively correlated with bluejoint (Calamagrostis canadensis) litter cover.     

Effects of white-tailed deer on vegetation structure and woody seedling composition in three forest types on the Piedmont Plateau

White-tailed deer (Ododcoileus virginiana) can substantially affect the structure and species composition of a forest. The tolerance of a forest community to browsing may vary by type as a result of varying biotic and abiotic factors of the environment. To date, no studies have compared the effects of browsing among forest communities within a physiographic region. We investigated the effects of browsing on vegetation structure and woody seedling composition in three forest types (oak–hickory, Virginia pine–eastern red cedar, bottomland hardwood) in Manassas National Battlefield Park (MNBP), Virginia, USA. We compared forb cover, vertical plant cover (0–1.5 m tall), and survival of tagged seedlings in 10 exclosed (2 m × 6 m) and 10 unexclosed plots in each forest type during a 5-year period. No differential effects of browsing were found among forest types. In all forest types, deer (67 deer/km²) suppressed forb and vertical plant cover to levels less than would be expected in the absence of deer. Seedling survival rates of most species were significantly reduced by browsing. By the 4th year of the study, box elder (Acer negundo), hickory (Carya spp.), and red maple (Acer rubrum) had been eliminated from unexclosed plots, and red and white oaks (Quercus spp.) dramatically reduced. Ash (Fraxinus spp.), black cherry (Prunus serotina), and hackberry (Celtis occidentalis), although significantly impacted, remained the most abundant species throughout the study. These findings suggest that white-tailed deer may be modifying the structure of the forest interior to the extent that it adversely affects wildlife species dependent on a dense understory to thrive. We predict that the future composition of forests in MNBP will shift towards stands with fewer species and a greater dominance of ash, black cherry, and hackberry, particularly in the oak–hickory and bottomland hardwood forests, where the majority of current dominants are most affected.     

云南镇雄县金佛山方竹低效林改造效果

金佛山方竹是中国西南地区特有竹种,云南省镇雄县有金佛山方竹林面积为3.23万hm²。多年来,由于竹农过度采笋,而忽视竹林的科学经营,导致大面积竹林低产低效。文章分析了镇雄县金佛山方竹低效林的成因,提出了具体的改造措施,评估了低效林改造效果,以期为提升竹林质量、提高竹林生产力提供技术支撑。     

To what extent do forest herbs recover after clearcutting in beech forest?

We studied the occurrence of 22 plant functional groups and the distribution patterns of 12 forest herbs in four clear-felled areas of different ages, and across ecotones between the forest and clearcuts in a 4383 ha beech forest in central Belgium. The main goal was to improve our knowledge on the clearcut harvesting system and its possible influence on herb vegetation. Within each study site, the herbaceous vegetation was sampled along a north–south and an east–west transect with points at 20 or at 10 m intervals. We studied a total of 82 vegetation relevés (4 m²) on 18 transects according to the Braun–Blanquet method. Around the study sites, the abundance of each species present was noted according to a grid-map with cells of 50 m × 50 m, up to a distance of 150 m from the clearcut edges. Differences in species’ cover percentage and frequency between the clearcuts and the surrounding matrix were tested. The colonisation rate for each species was calculated and possible effect of clearcut age on the plant composition was examined. Results of this study show that plant functional groups with a high conservation value, such as ancient-forest species, stress-tolerant species and autochorous species showed a progressive decrease in time after clearcutting. Most of the studied forest herbs had a lower frequency and/or cover in the clearcut areas than in the surrounding forest matrix. For some of these species, we found a progressive abundance decrease along a 150 m-gradient within the forest towards the clearcut (e.g. Dryopteris dilatata, Luzula pilosa, L. sylvatica, Oxalis acetosella). Others, such as Anemone nemorosa and Circaea lutetiana, are characterised by a regular cover in the forest which suddenly drops at the edge and sustains a very low level throughout the clearcut. If some forest herbs recover better than others, data collected so far indicate that most of the studied species are not able to recover such disturbed sites within a few years. We conclude that silvicultural systems should be adapted to the dispersal and recruitment limitations of forest herbs in order to enable their long-term conservation. To achieve this goal, management without large clear fellings and harvesting methods that never leave the ground completely bare are proposed as alternatives to the clearcutting system.     

甜龙竹不同栽培模式对土壤酶活性的影响及其相关因素分析

在云南省沧源佤族自治县勐甘村的甜龙竹(Dendrocalamus brandisii)基地,采取5种甜龙竹栽培模式：甜龙竹×核桃(ZH)、甜龙竹×西南桦(CK)、甜龙竹×杉木(ZS)、甜龙竹×古茶树(ZC)和甜龙竹×果树(ZG),研究不同栽培模式对土壤酶活性的影响,并分析土壤酶活性与土壤化学性质的相关关系。结果表明：甜龙竹不同栽培模式不同土层对土壤酶活性具有显著影响,不同栽培模式对甜龙竹土壤酶活性的影响排序为：ZS>ZH>ZG>CK>ZC;土壤酶活性随着土层深度的增加呈逐渐下降趋势,说明表层土的微生物生物量聚集的最多,能释放出较多的酶;土壤酶活性与有机质、有机碳、水解氮、有效磷、速效钾、全氮、全磷、全钾存在显著或极显著相关关系。研究认为,在营造和经营甜龙竹林时,选择与杉木共同栽植可以在一定程度上提高土壤中的酶活性,其中对土壤脂肪酶活性的提高最为明显。     

贵州赤水楠竹林菌笋复合经营技术

为充分利用楠竹林地空间,提高竹林经济效益,对楠竹林采用丰产技术措施培育笋用林,并在林下种植竹荪,实施菌笋复合经营。结果显示,通过对楠竹林采取调整立竹结构、劈山抚育、林地清理、林地垦复、留笋养竹、病虫害防治等一系列丰产技术措施,竹林春笋产量明显提高,较对照提高62.49%;若同时在林下种植竹荪,则春笋产量更高,较对照增加1.69倍,同时可收获鲜竹荪超过400 kg/667 m²。该研究总结出的一套楠竹林菌笋复合经营技术,具有重要的推广价值。     

Dead wood in European beech (Fagus sylvatica) forest reserves

Data were analysed on the volume of dead wood in 86 beech forest reserves, covering most of the range of European beech forests. The mean volume was 130 m³/ha and the variation among reserves was high, ranging from almost nil to 550 m³/ha. The volume depended significantly on forest type, age since reserve establishment and volume of living wood. More dead wood was found in montane (rather than lowland/submontane) reserves, longer-established reserves (time since designation) and reserves with higher volumes of living wood.

On average, fallen dead wood contributed more to the total dead wood volume than standing dead wood. The percentage of dead wood that was standing was almost twice as high in montane than in lowland/submontane forest reserves (45% versus 25%). The volume of dead wood at selected sites changed considerably over time. The fluctuations were significantly higher in lowland/submontane than montane reserves, possibly connected with differences in the disturbance regimes and especially damage caused by windstorms. In NW Europe, the blow down of formerly managed, even-aged stands led to extraordinary high volumes of dead wood shortly after reserve establishment.

The implications for forest management and biodiversity conservation are discussed. An increase in dead wood volumes must be carried out in accordance with the local/regional forest type and disturbance regime. Thus, in order to fulfil the requirements of as many wood-depending organisms as possible, it is important to preserve not only larger amounts of dead wood, but also dead wood of different types and dimensions as well as securing a long-term continuity of dead wood.     

油处理技术的发展——用棕榈藤生产高附加值产品

棕榈藤行业有一个普遍的不足,就是乡村产品的质量,尤其是家具质量的低劣,这不是因为藤质量或性能差,而是因为所采用的加工工艺落后。油处理指新鲜藤在热油中或油混合物中脱青。用该技术是为了改善藤的淡奶色的表皮,最后变成受欢迎的象牙色。同时,经过油处理,能大幅减少新鲜藤的含水率(30%～70%)。这有助于提高抵御真菌侵袭的能力。由于改善了藤表皮的颜色,产品的品质也由此提高了很多。经处理的藤有更好的出口潜力和国内市场,是改善贫困乡村生计的保证。这样,油处理技术能提高藤产品的品质和持久性,提高资源高效利用和高附加值利用,实现全球藤的可持续发展。     

麻竹新品种‘花融麻’

‘花融麻’ Dendrocalamus latiflorus ‘Huarongma’为牡竹属融水麻竹D. latiflorus var. rongshuiensis的变异植株培育而获得的竹类新品种。2020年发现于广西南宁市竹藤种质资源库,连续3年的新生竹秆变异特征一致、稳定。‘花融麻’与融水麻竹的关键区别在其秆基部节间绿色,间有粗细不一的淡黄色纵条纹,观赏价值较高。     

Impact of spatial heterogeneity of neighborhoods on long-term population dynamics of sugar maple (Acer saccharum)

We evaluated the impact of spatial heterogeneity resulting from disturbance and neighbor density on long-term population dynamics of sugar maple (Acer saccharum) in Brownfield Woods, an old-growth forest remnant in central Illinois. All trees with diameter at breast height (DBH) ≥ 7.6 cm in eight discrete quadrats (48 m × 68 m) and one large quadrat (216 m × 260 m) were mapped in Brownfield Woods in 1951, 1988, and 2001. Two sets of neighbor-specific transition matrices were constructed for two census periods (1951–1988 and 1988–2001) based upon historical maps of trees. Different neighborhoods defined by the occurrence of disturbance and neighbor density resulted in major differences in subsequent demography and population dynamics of A. saccharum in Brownfield Woods during 1951–2001. Disturbance subpopulations with high neighbor density demonstrated greater population growth than the other subpopulations and were characterized by relatively high recruitment and mortality. Dutch elm disease subpopulation shared similar characteristics. In contrast, non-disturbance subpopulations demonstrated census-specific demography. Using matrix modeling, we demonstrated the importance of spatial heterogeneity at the scale of neighboring trees to the dynamics at the scale of tree populations.     

Relationships between soil and foliar nutrients in young densely planted mini-plots of Pinus radiata and Cupressus lusitanica

The long-term nature of forest crop rotations makes it difficult to determine impacts of forestry on soil nutrients that might be depleted by forest growth. We used small scale, highly stocked plots to compress the length of the rotation and rapidly induce nutrient depletion. In the study, two species (Pinus radiata D. Don and Cupressus lusitanica Miller) are compared under two disturbance regimes (soil undisturbed and compacted), and two fertiliser treatments (nil and plus fertiliser), applied in factorial combination at 33 sites, covering the range of climatic and edaphic variation found in plantation forests across New Zealand. To assess our ability to rapidly highlight important soil properties, foliar nutrient concentrations were determined 20 months after planting. It was hypothesised that the densely planted plots, even at a young age, would create sufficient pressure on nutrient resources to allow development of relationships between properties used as indicies of soil nutrient availability and foliar nutrient concentrations. For both species significant relationships between foliar nutrients and 0–10 cm layer soil properties from unfertilised plots were evident for N (total and mineralisable N) and P (total, acid extractable, organic, Bray-2 and Olsen P). With the exception of Ca in C. lusitanica, foliar K, Ca and Mg were correlated with their respective soil exchangeable cation measures. The results thus confirm the utility of the experimental approach and the relevance of the measured soil properties for forest productivity.

In unfertilised plots foliar N and P concentrations in P. radiata exceeded those in C. lusitanica, the differences being eliminated by fertiliser application. Foliar N/P ratios in P. radiata also exceeded those in C. lusitanica. In contrast to N and P, foliar K, Ca and Mg concentrations were all higher in C. lusitanica, the difference being particularly marked for Ca and Mg. P. radiata contained substantially higher concentrations of the metals Zn, Mn and Al than C. lusitanica, whereas the latter contained higher B concentrations. Possible reasons for differences between species in foliar nutrient concentrations are discussed.     

Truffle abundance and mycophagy by northern flying squirrels in eastern Washington forests

Although much is known about truffle abundance and rodent mycophagy in mesic Douglas-fir forests in the Pacific Northwest, few data are available for dry interior montane forests dominated by ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii), and grand fir (Abies grandis). Our objective was to quantify the relationship between the abundance and diversity of ectomycorrhizal fungal sporocarps in the soil and in the diets of northern flying squirrels (Glaucomys sabrinus) in low-elevation forests of the eastern Washington Cascades. We randomly sampled four stands each of three cover types: dry open ponderosa pine, mesic young mixed-conifer forest, and mesic mature mixed-conifer forest. We sampled the soil for hypogeous sporocarps during the spring of 1999 and 2000. We collected fecal pellets from 318 flying squirrels live-trapped during the fall of 1997–2000. We sampled 2400 m² of soil surface and found truffles in 40% of 600 plots. Total biomass collected was 609 g. Spring truffle biomass on a kg/ha basis averaged 1.72 in open pine, 3.56 in young, and 4.11 in mature forest. Twenty-two species were collected across all cover types, with all but three species belonging to the Basidiomycotina. Eleven dominant species accounted for 91–94% of truffle biomass in each cover type. Four dominant species accounted for 60–70% of spring truffle biomass: Gautieria monticola, Hysterangium coriaceum, Rhizopogon parksii, and R. vinicolor. Truffle assemblages, richness and total biomass differed among cover types: richness and biomass were highest in young and mature mixed-conifer forest, and lowest in open ponderosa pine forest. Fall squirrel diets were composed of 23 genera or groups of fungi, plus about 22% plant material. Rhizopogon was the most abundant genus in the diet, followed by plant material, then Gautieria, Leucogaster, Alpova, and Hysterangium. Diets in different cover types were similar in the composition, richness, evenness, and the ratio of fungus to plant material. Diet richness varied over the study period. Nineteen truffle genera were detected in fall fecal samples versus 12 in spring soil samples. Management of low-elevation dry forest to maintain or restore stable fire regimes might reduce truffle diversity at stand scales by simplifying stand composition and structure; but, such management might increase long-term beta and landscape truffle diversity and persistence by reducing the occurrence of high-intensity fires and stabilizing inherent fire disturbance regimes.     

Rainfall interception and fog precipitation in a tropical montane cloud forest of Guatemala

Tropical montane cloud forest hydrology is complex because of the presence of epiphytic life-forms that increase canopy surfaces and fog persistency. Fog precipitation is a hydrological input common to cloud forests, and forms when fog droplets are intercepted by the canopy and fall to the forest floor. Interception and fog precipitation was determined for a 2100 m site and a 2550 m site in a first-order tributary of the Sierra de las Minas Biosphere Reserve, Guatemala by calculating the difference between throughfall and gross precipitation for a 44-week period. Both sites were situated within closed-canopy cloud forests. The 2100 m site was on the windward slope of Montaña de Miranda near the lower boundary of the cloud forest and the 2550 m site was at the summit. Fog precipitation was found during periods in which throughfall exceeds gross precipitation. Fog precipitation was greater at 2550 m than at 2100 m. Data collected by precipitation and throughfall gauges demonstrate the existence of seasonal fog precipitation with the greatest fog precipitation occurring in the dry season (November–April). Fog precipitation contributes approximately 1 mm per day to the hydrological budget of the cloud forest at 2550 m during the dry season, and 0.5 mm per day during the rainy season (May–October).     

非洲藤(Palmae calamoideae)的两个新种

藤类广泛分布于非洲大陆热带森林的低地上,对区域林业经济发挥着重要作用。在非洲分布的20种之中有6种已被用于商业资源开发。尽管非洲藤类的经济价值很高,但至今对它们的分类仍不太确定。本文描述了单苞藤属和肿胀藤属的2个新种,分别从分类学、形态学、特征、生物学特性、保护和利用等方面做了研究。