The Conservation of Saproxylic Insects in Tropical Forests: A Research Agenda

Invariably, insects are overlooked when tropical forest management issues are discussed, because there are so many species, they are taxonomically intractable and so poorly known. Often people take the view that if you look after the vegetation and vertebrates, the insects will look after themselves. This may be true for some functional groups, but for saproxylic insects, this seems unlikely. Their study deserves high priority, since they are dependent on the very resource – wood – whose removal from the ecosystem is the usual object of forest management. Given the current international effort to develop 'criteria and indicators' to monitor sustainable forest management for biodiversity values, there is a window of opportunity for sound ecological research on saproxylic insects to influence the formulation of forest policy such that their needs can be taken into account. There is already a large body of knowledge on temperate and boreal region saproxylic insects, and on the effects that logging has on them, but knowledge of the tropical forest situation lags far behind. This paper proposes a research agenda to enable the needs of saproxylic insects to be taken into account in natural forest management in the tropics. Basic questions, such as whether logging has so far had an impact on tropical saproxylic insects, and whether there are workable sampling techniques to investigate this, still remain to be addressed and deserve high priority. The links between the responses of saproxylic insects and more 'charismatic' study species need to be investigated. We also need to know whether there is a correlation between the intensity of logging and the response of saproxylic insects, and, critically, whether we would be justified in measuring some surrogate aspects of forest structure (as potential habitat for saproxylic insects) rather than the saproxylic insects themselves, and modelling this to determine likely impacts of different management regimes. We consider such an ambitious research agenda as justified given the scale of impact that forest use and management is likely to have on tropical forest insects in the future.     

Degradation of Tribromophenol by Wood-Decaying Fungi and the 1,2-Dihydroxybenzene-Assisted Fenton Reaction

The degradation of 2,4,6-tribromophenol (TBP) by biological and chemical treatments was studied. Biological treatment involved the use of Laetoporeus sulfureus, Gloephyllum trabeum, and Ganoderma australe in liquid culture. Despite the inhibitory effects of TBP on the fungal growth, these fungi were able to degrade TBP after 15 days of biotreatment. At 66, 116, and 183 μ M TBP, the degradation by G. australe was the most efficient (71% to 77%), whereas G. trabeum and L. sulfureus degraded between 50% and 60% of three TBP concentrations. The removal of organic bromine reached values of 50% in all cases. The chemical treatment (1,2-dihydroxybenzene-assisted Fenton reaction) achieved up to 90% of TBP degradation. However, only 40% of TBP was mineralized and the toxicity level did not undergo changes during the chemical treatment. On the other hand, a 30% reduction in toxicity was obtained with a combined chemical-biological treatment.     

Spatiotemporal Patterns of Laccase Activity in Interacting Mycelia of Wood-Decaying Basidiomycete Fungi

Abstract Interspecific fungal interactions are important ecological processes, whereas their physiological mechanisms are little understood. The aim of this work was to study how activity of fungal extracellular laccase was changed across mycelia during interactions between white- and brown-rot basidiomycetes from different wood decay stages. Qualitative assay of eight species interacting with each other in all combinations showed four spatial patterns of laccase activity: (I) laccase activity present both in contact zone and mycelium, (II) laccase activity only in contact zone, (III) laccase activity in mycelium but not in contact zone, (IV) no laccase activity. Presence of laccase activity only in the contact zone was more frequent than expected from random samples associated with mycelia that replaced other ones. On the other hand, the presence of laccase activity in the mycelium but not in the contact zone was only attributed to fungal species that were replaced by their antagonists. After one month, laccase activity was distributed over mycelia more homogeneously than after 6 days of interactions. In interacting mycelia, laccase activity was higher than in control and increasing with time. Saprotrophic fungi from late successional stages of wood decay generally had higher laccase activity than early succession saprotrophic and pathogenic fungi. The qualitative assays were confirmed by quantitative assay of total laccase activity. Significance of the results in antagonistic fungal interactions as well as in the processes of hyphal tip growth and mycelium senescence is discussed. Received: 6 October 1999; Accepted: 1 February 2000; Online Publication: 5 May 2000     

Effects of Clearfell Harvesting on Lucanid Beetles (Coleoptera: Lucanidae) in Wet and Dry Sclerophyll Forests in Tasmania

The effects of commercial forestry harvest and regeneration practices (clearfelling and slash-burning) on the lucanid fauna of the wet sclerophyll forests of southern Tasmania and the dry sclerophyll forests of eastern Tasmania were examined using pitfall catches. Lucanids are saproxylic beetles, dependent on dead, moribund and decaying wood. Samples taken from old-growth forest and from a chronosequence of sites regenerating after logging, in each forest type, were used to compare the species richness and abundance of the lucanid assemblages. In both forest types, species richness and abundance was highest in the youngest regeneration sites (1–3 year), reflecting the species richness of the original and adjacent unlogged forest, lowest in the older (20–25 year) sites, and variable in the old-growth sites. TWINSPAN cluster analysis showed no clear distinction between regeneration and old-growth forest. The post-harvest slash and stump residue provided an important refugium and initial habitat, but our research indicates that some species may not maintain populations in the long term. Our results suggest that most species of lucanids will find a continuous supply of suitable habitat only in old-growth forests; and such species may become less common as clearfell harvesting leads to a replacement of heterogeneous old-growth forest with single-aged monospecific stands. Continuity of supply of wood in all decay stages, the maintenance of sufficient source areas, and biological connectivity between old-growth stands to enable dispersal, are all likely to be essential to maintain lucanid beetle community integrity. If similar principles apply to other saproxylic species of invertebrate, then clearfelling and slash-burning may cause a gradual extinction of an important element of the forest biota.     

Antifungal Activity of Cadinane-Type Sesquiterpenes from Eupatorium adenophorum against Wood-Decaying Fungi

The present study aimed to evaluate the antifungal activities of Eupatorium adenophorum against four strains of wood-decaying fungi, including Inonotus hispida, Inonotus obliquus, and Inonotus cuticularis. Bioguided isolation of the methanol extract of E. adenophorum by silica gel column chromatography and high-performance liquid chromatography afforded six cadinane-type sesquiterpenes. Their structures were identified by nuclear magnetic resonance and MS analyses. According to the antifungal results, the inhibition rate of the compound was between 59.85 % and 77.98 % at a concentration of 200 μg/mL. The EC₅₀ values ranged from 74.5 to 187.4 μg/mL.     

菌物的种类多样性

本文在物种的层次上概述全世界的菌物多样性并试论菌物多样性调查及保护的必要性。     

New Zealand's giant Collembola: New information on distribution and morphology for Holacanthella Börner, 1906 (Neanuridae: Uchidanurinae)

Abstract

The New Zealand collembolan fauna currently includes five described species of the striking endemic genus Holacanthella (springtails). Holacanthella species are saproxylic decomposers of cool temperate forest ecosystems, and they contribute to nutrient cycling of coarse woody debris. All species of the genus have the dorsal and lateral surfaces furnished with conspicuous red, orange, yellow or white digitations. They are among the largest Collembola known, with some individuals reaching 17 mm in length. We examined new material of the five species from throughout New Zealand, as well as existing museum material, to understand more fully their distributions. We provide an updated key to the five Holacanthella species and discuss the conservation of rare/range restricted species, and propose hypotheses to explain their distributions. One species, H. laterospinosa, is known only from Cuvier Island and the Coromandel Peninsula, North Island, but the distributions of the remaining four species appears to reflect the turbulent geological history of New Zealand during the Pliocene. Intraspecific variation in several gross morphological characters was observed in all species. We provide a comparison of characters with the other genera within the Uchidanurinae in order to characterise the genus more fully with respect to allied genera. Holacanthella species are particularly vulnerable to human‐mediated disturbance by forest modification because of their strict habitat requirements and low mobility, and we stress that conservation efforts should focus on protecting critical habitats for each species.     

Spatial Peculiarities in the Colonization of the Plant Rhizoplane by Microscopic Fungi

Spatial peculiarities in the colonization of the tomato, cucumber, and barley rhizoplanes by microscopic fungi were studied. The apical zone of roots was colonized with a limited number of Rstrategists (the order Mucorales, Fusariumsp., Aspergillus niger, and Mycelia sterilia). The fungal population of the root hairs and the basal zone of roots was 2- to 3-fold denser due to the prevalence of Kstrategists. Fusaria, Fusarium oxysporumin particular, colonized roots in earlier terms than the genera Trichoderma, Penicillium, Gliocladium, and others. The F. oxysporumpopulation was at a maximum in the rhizoplane zone nearest the root tip.     

Insects on the brink of a major discontinuity

Population surges and local extinctions are not uncommon among insects. In response to climatic changes in the past, insects have often shifted their ranges. This long-term range shifting and the vagaries of short-term weather makes reserve selection unrealistically rigid for many species. Although some insect species are surviving in reserves, others have disappeared from such small areas because of adverse weather. In contrast, many other insects depend on localized disturbance for survival. In response to anthropogenic disturbance, some native insects have become more abundant and widespread, such as Orthoptera in response to grazing and burning, and some Odonata in response to aquatic weeds and water impoundment. The effect of some exotic invasive insects on some native ecosystems is of major concern. Human-induced insect population crashes and species extinctions are becoming more common and widespread, and exacerbated by the synergistic effect of the various local impacts with global changes. A major insect population and species extinction discontinuity is beginning to take place. Yet, there is also an increase in range and abundance of some other insects. The world is becoming increasingly species-poorer and more homogenous in its insect fauna.     

Horizontal and vertical distribution of saproxylic beetles (Col., Buprestidae, Cerambycidae, Scolytinae) across sections of forest edges

Abstract:  We evaluated the preferred home ranges of three saproxylic beetle taxa along transects from the open field into the forest interior, and from the forest floor up to the canopy. By means of trap sets on metal scaffolds, vertical and horizontal strata were sampled across two types of forest edges: soft-edge ecotones with a gradual transition from the field into the forest and hard edges with an abrupt transition. The forest edges consisted of different strata such as herbaceous fringe, shrub belt, unmanaged forest and managed forest. The thermophilic buprestids were mainly caught in the open land (herbaceous fringe and agricultural land) and in the upper forest mantle. In general, the cerambycids were most abundant in the open land and the lower forest mantle, but a few species favoured the forest interior. The bark beetles (Scolytinae) were equally distributed in all habitats. These distribution patterns of the taxa were observed in terms of both species numbers and abundances. Each species with at least five collected specimens was assigned to one of the three habitat types: open land, forest mantle and forest interior. Of 74 ranked species, only 16% were prevalent in the forest interior and are thus considered to be true forest species. The other 84% of the species were attributed to open land or the forest mantle and are, therefore, forest edge species. Soft forest edges generally supported a higher species richness than hard edges, particularly as regards Cerambycidae and Scolytinae. In terms of Shannon diversity, soft edges tended to be more diverse in buprestids and cerambycids. Overall, the forest interior showed the least species richness and diversity. Therefore, for the conservation of saproxylic beetles, not only the amount and quality of dead wood is important, but also the presence and design of forest boundary structures.     

广西森林土壤丝状真菌的生态分布

真菌种类多,分布广,对人类的生产和生活关系非常密切,因此近来对真菌特别是丝状真菌的研究日益引起高度重视。1981—1990年我们对桂北龙胜县里骆林区、桂中宜山县庆远林区、桂南岑溪县七坪林区和桂西田林县老山林区森林土壤微生物区系进行了分析,其中丝状真菌是我们重点研究的内容之一。在上述森林土壤中共分离出丝状真菌2084株,经鉴定归属于25属。现将广西森林土壤丝状真菌生态分布的研究结果报道如下。     

东喜马拉雅山地区木材腐朽菌研究5.多孔菌的多样性（英文）

对中国西南部的东喜马拉雅山地区进行了16次野外考察,共采集孔状木生真菌标本约2 440号。本文是对这些标本研究的总结。报道该地区多孔菌391种,给出了每种的寄主和生长基质。灰皮多孔菌Polyporus cuticulatus为新种,对该种进行了描述和绘图,并提供了ITS和LSU序列。     

大兴安岭林区多孔菌的区系组成与种群结构

本文在过去10 a野外调查和室内鉴定及分析研究的基础上,对大兴安岭林区多孔菌的区系组成和种群结构进行了分析,发现大兴安岭林区的多孔菌具有较高的多样性,共有5目11科56属129种,占中国多孔菌区系的21.36%,优势科是多孔菌科。种的区系地理成分分为7类,以北温带成分和世界广布成分为主,具有明显的北温带成分的区系特征。大兴安岭的多孔菌常见种较多,种群结构中共生菌3种,寄生菌27种,腐生菌占大多数,有99种。在能够引起木材腐朽的126种真菌中,白腐菌93种,占多数,褐腐菌33种,占少数,但该地区褐腐菌所占比例明显高于全国范围内褐腐菌在多孔菌中的比例。通过对大兴安岭主要树种上的种群结构进行比较,表明阔叶树上的木材腐朽菌绝大部分是白色腐朽菌,而针叶树上的白腐菌与褐腐菌数量相差不大,褐腐菌对于针叶林特别是落叶松的更新具有非常重要的作用。     

Patterns of saproxylic beetle succession in loblolly pine

• 1 Patterns of insect succession in dead wood remain unclear, particularly beyond the first several years of decay. In the present study, saproxylic beetles were sampled from loblolly pine (Pinus taeda L.) logs aged between 1 month and 9 years old using both emergence traps attached to logs in the field and rearing bags in the laboratory.
• 2 Species richness peaked within the first year as a result of a diverse assemblage of bark beetles, wood‐borers and predators associated with young logs. After the phloem phase, there were no significant differences in species richness among decay classes.
• 3 Beetle communities differed significantly among decay classes, with 25 and seven species being significantly associated with young and old logs, respectively.

     

Dependence on Fire in Wood-living Insects: An Experiment with Burned and Unburned Spruce and Birch Logs

Several boreal wood-living insect species breed exclusively in recently burned forest. However, the reason for this dependence on fire is largely unknown. Here wood-living insects and other arthropods were sampled from burned and unburned logs of birch and spruce in a burned forest, together with unburned logs at a clearing and in an uncut forest, during two years of succession after tree death. Burned spruce logs hosted fewer beetles than unburned logs. Notably, bark-beetles and their associated fauna, responded negatively to fire-scorching of the logs while arthropods that feed on ascomycete fungi responded positively. Fire-scorched logs more often had visible ascomycete fungi, and lost their bark faster than unburned logs. However, despite this obvious effect of fire-scorching of the logs, the species composition in burned and unburned logs at the burned site was more similar than in unburned logs at the three different sites. A larger diversity of beetles, when measured with rarefaction, was found for fire-scorched logs. When sites were compared, birch logs had the most diverse fauna at the burned site and spruce logs in the uncut forest. Pyrophilous insect species were almost exclusively confined to the burned forest, but occurred in both burned and unburned logs. These species may be divided into two groups: (1) mycophagous species that need burned substrate per se because ascomycete fungi are favoured by burning, and (2) phloem-feeders and predators that are favoured by some habitat characteristic of recently burned forest rather than of burned wood.     

多年卧孔菌属五个中国新记录种

报道了多年卧孔菌属Perenniporia5个中国新记录种。非洲多年卧孔菌Perenniporia africana采自安徽省,孔口表面浅黄色至赭色,且骨架菌丝不分枝;下延多年卧孔菌P.decurrata采自云南省,担子果盖形,具较小孔口和担孢子;椭圆孢多年卧孔菌P.ellipsospora采自云南省,担子果平伏,孔口圆形至多角形,担孢子不平截;硬多年卧孔菌P.inflexibilis采自福建省,担子果盖形,孔口表面灰白至浅褐色,担孢子无色至浅黄色;黄多年卧孔菌P.xantha采自海南省,孔口较小,表面呈黄色,且在KOH试剂中呈深褐色。根据采集的标本材料提供了它们的详细描述和显微结构图。     

Patterns of invertebrate food availability and the persistence of an avian insectivore on the brink

Globally, insectivorous birds are at high risk of decline. One explanation of this relates to changes in invertebrate resources due to anthropogenic pressures. The northern population of the eastern bristlebird (Dasyornis brachypterus) relies heavily on invertebrate food resources, and has experienced an 80% population reduction over the past 40 years. We investigated invertebrate abundance and nutritional quality across 23 currently and historically occupied northern bristlebird sites to determine whether extant territories were associated with more, or more nutritious, invertebrate resources. Pitfall and leaf‐litter invertebrate sampling were done in both breeding and non‐breeding seasons from 2014 to 2016. There was no difference in abundance, biomass or nutritional value of invertebrates between occupied and abandoned territories; however, within territories invertebrate abundance and nutritional value did correspond to the habitat characteristics with which bristlebirds are associated. Nutritional value of invertebrates increased with proximity to rainforest, while the abundance of macro‐invertebrates (>1 mm) was correlated with grass height. Bristlebird territories are often close to rainforest margins, and these ecotones may provide more nutritious mesic‐associated invertebrates. Higher abundances of large invertebrates in tall grasses may also contribute to the known association of bristlebirds with tall grasses. Maintenance of tall grass adjacent to rainforest through appropriate fire and grazing management is likely to be important for northern bristlebird recovery and long‐term persistence of the population.     

Dead trees left in clear-cuts benefit saproxylic Coleoptera adapted to natural disturbances in boreal forest

Forest management alters the pattern of forest dynamics from that in natural conditions in the boreal region. In order to examine how certain forestry measures matching natural dynamics affect forest insects, we compared assemblages of saproxylic Coleoptera on dead, standing birch trunks left behind in eight clear-cut areas with corresponding assemblages in seven mature forests in southern and eastern Finland. We used trunk-window traps for sampling. Distinct beetle assemblages were associated with the different habitats. Median numbers of species or specimens caught did not differ between closed forests and clear-cuts, but individual beetle species occurred unevenly among the habitats. Several beetle species associated with open forest habitat, e.g. burned forests or storm-damage areas, including species regarded as threatened in Finland, were found almost exclusively, in clear-cuts. Correspondingly, a number of beetle species occurring frequently in closed forests were not found in clear-cuts. We conclude that dead trunks left in the clear-cut areas may host not only generalist saproxylic species but also many beetle species specialized to warm, sun-exposed environments, and such species may not be able to survive in closed forests. Management measures matching suppressed natural disturbances are found useful in preserving diversity in managed forests.     

不同程度铅锌污染区丛枝菌根真菌和深色有隔内生真菌侵染特征

对陕西凤县铅硐山铅锌矿区4个不同程度铅锌污染样地植物根系的丛枝菌根真菌(AMF)和深色有隔内生真菌(DSE)进行了资源和分布调查。结果表明:(1)无铅锌污染的矿山上调查的15种植物中除黄连木没有检测到AMF侵染、栓皮栎和酸模不能被DSE侵染外,其他植物均能与AMF和DSE共生,但平均侵染率较低,仅分别为32.3%和25.9%;铅锌轻度污染的尾矿荒地和铅中度污染、锌重度污染的尾矿坝植物根系内AMF和DSE侵染率明显提高,AMF的平均侵染率分别为53.3%和68.3%,DSE的平均侵染率分别为38.6%和54.2%;铅锌重度污染的废弃冶炼厂样地植物AMF侵染率明显下降,平均只有17.6%,而DSE的侵染没有受重金属污染的抑制,仍达到60.3%。(2)4个样地植物根际土壤中AMF孢子分布不均匀,每克土的孢子密度在0.08～6.84个,平均为1.5个。对4个样地均有分布的狼牙刺、博落回、山蒿和秦岭风毛菊的AMF、DSE侵染状况调查发现,轻度和中度的铅锌污染能促进AMF与宿主共生关系的建立,而重度污染则显著抑制AMF侵染;AMF孢子密度没有呈现一定的规律性,且与AMF侵染率之间没有显著相关性;DSE侵染率与土壤锌含量存在显著正相关关系(r=0.505,P<0.05),而与土壤铅含量没有显著相关性。可见,AMF和DSE能够广泛存在于铅硐山铅锌矿区,尤其是DSE表现出较强的耐受性和适应性。