Diversity in soil fungi from undisturbed and disturbed Celtis tala and Scutia buxifolia forests in the eastern Buenos Aires province (Argentina)

The rhizospheric soil microfungi from a native forest (undisturbed and disturbed) were studied using soil dilution plate and soil washing methods. Fungi were isolated using slightly acid and alkaline culture media. 54 taxa were isolated: 49 from undisturbed forest soil and 37 from disturbed forest soil. Acremonium sp., Aspergillus ustus, Coemansia pectinata, Doratomyces stemonitis, Fusarium solani, F. oxysporum, Gliocladium roseum, Humicola fusco-atra, Mortierella sp., Penicillium lilacinum, Trichoderma harzianum, and T. koningii, showed the highest frequency, in both, undisturbed and disturbed forests. In undisturbed soil forest the biodiversity index was 3.97 whereas in disturbed ones was 3.89.     

Materials for the fungus flora of Japan (53)

Two interesting ascomycetes are described as new to Japan:Ascotricha amesii (Xylariaceae), isolated from garden soil in Osaka; andAuxarthron reticulatum, isolated from forest soil in Tokyo. ADicyma anamorph is associated with the former species. (52): Tubaki, K., Tokumasu, S. and Konno, M., Nippon Kingakukai Kaiho38: 249–250. 1997.     

Emericella omanensis,a new species from Oman soil

A new species ofEmericella isolated from forest soil in the Oman,E. omanensis, is described and illustrated. It differs from the other known species of the genus in having bivalvate ascospores with a tuberculate or verruculose convex wall. The new species is compared with the closely related speciesE. desertorum andE. echinulata.     

<Emphasis Type="Italic">Kazachstania wufongensis</Emphasis> sp. nov., an ascosporogenous yeast isolated from soil in Taiwan

A new yeast species, Kazachstania wufongensis, is proposed in this paper based on six strains isolated from soil in Taiwan. The species may produce one to four ellipsoidal ascospores in each ascus, directly transformed from diploid cells. Genus assignment and distinction of the species from other recognized species of Kazachstania is based on morphological and physiological characteristics, and on phylogenetic analysis of nucleotide sequences of the D1/D2 domains of the large subunit (LSU) rRNA gene. Sequence analysis of the D1/D2 domains of the LSU rRNA gene reveals that K. wufongensis is a member of the Kazachstania exigua complex, and its phylogenetically closest relatives are K. exigua, K. barnettii, K. bulderi, and K. turicensis. The species can be further differentiated from the other phylogenetically related species based on internal transcribed spacer sequence and electrophoretic karyotype. Therefore, the new species Kazachstania wufongensis sp. nov. is proposed. The type strain of this new species, which was isolated from forest soil in Wufong, Hsinchu, Taiwan, is FN21S03^T (=CBS 10886^T = BCRC 23138^T).     

Effects of Forest Use on Aphyllophoraceous Fungal Community Structure in Sarawak, Malaysia

Aphyllophoraceous fungi are expected to reflect changes in the environmental conditions caused by forest use. To reveal the effects of forest uses on the fungal community structure, we performed a 3‐month survey of aphyllophoraceous species in five forest types (undisturbed primary forest, isolated patches of primary forest, old and young fallow forest, and rubber plantations) in Sarawak, Malaysia in 2005. We used a canonical correspondence analysis (CCA) to reveal the relationships between fungal community composition and the environmental variables (canopy openness, soil water potential, amount and composition of coarse woody debris, litter mass, basal area, plant species composition). A total of 155 samples from 67 species were collected during the study period. The fungal species density represented by the number of species in a transect differed significantly among forest types. The fungal species density increased significantly with increasing number of pieces of coarse woody debris (CWD), but decreased significantly with increasing the scores of second axis of principal component analysis (PCA) for plant species composition. In the CCA ordination, automatic forward selection revealed that only the number of pieces of CWD significantly affected the fungal species composition. The occurrences of Flabellophora licmophora, Coriolopsis retropicta, Microporus vernicipes, and Amauroderma subrugosum were positively correlated with the number of pieces of CWD. Our study clearly demonstrated that forest use negatively affected aphyllophoraceous fungal diversity and suggest that the quantity of CWD would be an important determinant of fungal diversity and composition.     

喀斯特森林常见树种倒木分解对土壤真菌群落组成及分布规律的影响

倒木是森林生态系统的重要组分,其分解调控着土壤的养分循环,同时也影响着土壤微生物群落结构。但目前鲜见关于倒木分解对土壤微生物群落影响方面的报道。选取贵州茂兰喀斯特常绿落叶阔叶混交林中处于轻、中和重度腐烂等级的狭叶润楠（Machilus rehderi）、枫香（Liquidambar formosana）、青冈栎（Cyclobalanopsis glauca）和圆果化香（Platycarya longipes）4种常见树种倒木为研究对象,以距倒木外围的3个不同水平距离（10cm、30cm和50cm）的土壤样品为实验材料,分析倒木树种、腐烂等级和距离对土壤真菌种类及多样性的影响。结果表明：1）喀斯特森林4种树种倒木所影响土壤真菌群落在门级分类上主要为子囊菌门、担子菌门和毛霉门,优势属有Mortierella spp.、Phlebia spp.、Pluteus spp.和Chaetomium spp.等;2）倒木的树种对土壤真菌群落相对丰度的影响有差异,圆果化香倒木下的土壤真菌丰富度Chao1指数显著高于青冈栎;3）随腐烂程度加深,4种树种倒木下的土壤真菌群落多样性呈显著增加趋势;4）土壤真菌群落丰度随着距倒木距离的增大（10-50cm）变化明显,如狭叶润楠影响的Pluteus spp.、Mortierella spp.和Ganoderma spp.,枫香的Chaetomium spp.,圆果化香的Mortierella spp.和青冈栎的Phlebia spp.和Oliveonia spp.等。本研究量化了喀斯特森林倒木所影响的土壤真菌群落组成及分布规律,在一定程度上为倒木分解与土壤微生物群落之间的作用机制的深入探索提供了科学依据。     

Four endoparasitic nematode destroying fungi isolated from Sand Ridge State Forest soil

A survey to determine the endoparasitic nematode destroying fungi located within Sand Ridge State Forest of Illinois was conducted from 1 January to 3 April 1973. A total of seven nematode destroying fungal species were isolated from the collected soil samples. Harposporium helicoides, H. crassum, H. lilliputanum are endoparasitic nematophagous fungi that have been isolated previously from the forest soil. Acrostalagmus gonoides, A. obovatus, Cephalosporium balanoides, and Monacrosporium cionopagum are nematophagous fungal species that had not been isolated previously from Illinois soil. Soil pH's and soil nutrient levels were not important in the isolation frequency of the collected endoparasitic nematode destroying fungi.     

Occurrence and diversity of plasmids in populations of streptomycetes in soil

Studies were made of naturally occurring plasmids hosted in Streptomyces strains isolated from two different terrestrial ecosystems: an agricultural field and a protected forest area. Six out of the 147 screened isolates contained plasmids. The strains containing these plasmids were all isolated from the agricultural soil. Plasmids were not found among the strains isolated from the forest area. Cross hybridization of the six newly isolated plasmids revealed very high similarities between four of them. However, no similarities were found between the six newly isolated plasmids and well studied streptomycete plasmids such as pIJ101 and SCP2^*. The host strains of the four similar plasmids belonged to three different species S. anulatus, S. rochei and S. diastaticus. This implies a possible conjugative transfer of these plasmids within the streptomycete population in the agricultural area. The reason for the absence of streptomycete plasmids from the populations derived from the forest area is discussed.     

Factors Limiting the Survival of Native Tree Seedlings Used in Conservation Efforts at the Edges of Forest Fragments in Upland Madagascar

We tested four reforestation techniques in tropical forest fragments that were damaged by fire in upland Madagascar. We conducted a full‐factorial experiment on the survival of transplanted seedlings of five native tree species in grassland plots adjacent to the forest fragments in the Ambohitantely Forest Reserve. The species studied were Dodonaea madagascariensis, Filicium decipiens, Olea lancea, Podocarpus madagascariensis, and Rhus taratana. A total of 480 seedlings were planted; 207 survived the 15 months of the experiment. The factors examined were distance of the reforestation plots from the forest, mixing of forest soil into the plots, application of chemical fertilizers, experimental shading of plots, and the cover of naturally establishing shrubs. Both increasing the distance of plots from the forest edge and adding chemical fertilizers significantly reduced the survival of all seedlings. The surprising negative effects of fertilization may be partly due to increased competition from naturally establishing shrubs that are adapted to exploit high nitrogen levels. Mixing soil from the forest areas into the plots did not change seedling survival. Shading reduced the survival of D. madagascariensis seedlings and did not increase the survival of any species. These findings suggest that the success of reforestation projects can be increased by planting seedlings close to the existing forest fragments. Reforestation of similar tropical forests is likely to be more successful if efforts are focused on expanding the size of existing fragments of tropical forest, rather than on establishing new fragments in grassland openings.     

Community dynamics of evergreen broadleaf forests in southwestern Japan. II. Species composition and density of seeds buried in the soil of a climax evergreen oak forest

The species composition and density of seeds in the soil of a climax evergeen oak forest in the Kasugayama Forest Reserve, Nara, Japan were studied by directly extracting seeds from soil samples and using soil samples in planting boxes as the basis of germination tests. A total of 33 species were identified from all seeds collected in 6 stands: 11 evergreen broadleaf, 15 deciduous broadleaf, 2 coniferous, 2 liana, 1 herb, and 2 grass species. Species producing sap fruits and dry fruits accounted for 60% and 40% of the total number of species, respectively. The species composition of all the seeds was independent of the species composition of the forest vegetation. The mean density of the seeds was 22,134 seeds/m²·5 cm.Eurya japonica, of which seeds were found in all soil samples, was the most abundant species, followed byCryptomeria japonica, Ilex micrococca, andBoehmeria longispica. Pioneer species such asMallotus japonicus, Zanthoxylum ailanthoides, andAralia elata were found in all soil samples in spite of the paucity of adult trees in the forest. Seeds of evergreen oaks were relatively aboundant but no viable seeds were found. ViableE. japonica, I. micrococca, Symplocos prunifolia, andB. longispica seeds were abundant.     

自然林下与田间根腐三七根际微生物群落特征及比较分析

【背景】三七根际微生物群落特征与其土传根腐病害密切相关,而针对自然林下根腐三七的相关研究鲜见报道。【目的】比较分析自然林下与田间根腐三七根际土壤微生物群落的组成特征,结合土壤理化性质与酶活性分析,为三七根腐病害防治与仿野生栽培提供科学依据。【方法】采集自然林下与田间根腐三七根际土壤,利用高通量测序技术,分析土壤细菌与真菌群落的物种组成与多样性,并测定土壤理化性质和酶活性。【结果】自然林下与田间根腐三七根际土壤中细菌和真菌群落组成具有明显差异,自然林下根腐三七根际土壤中担子菌门(Basidiomycota)、酸杆菌门(Acidobacteria)和疣微菌门(Verrucomicrobia)的相对丰度较高,而田间根腐三七根际土壤中子囊菌门(Ascomycota)、变形菌门(Proteobacteria)和绿弯菌门(Chloroflexi)的相对丰度较高。在属分类水平,镰刀菌属(Fusarium)是自然林下根腐三七根际土壤中的优势菌群,相对丰度为17.30%,而癣囊腔菌属(Plectosphaerella)是田间根腐三七根际土壤中的优势菌群,相对丰度为22.55%;Candidatus Ba...     

甘南黄河流域4种典型林分土壤C、N、P化学计量特征

土壤碳（C）、氮（N）、磷（P）是参与植物光合作用和影响生态系统初级生产力的主要元素。甘南高原是黄河流域重要的生态屏障,为了解该区不同林分土壤养分状况的差异,选取该区4种典型林分：云杉林、华北落叶松林、巴山冷杉林以及岷江冷杉糙皮桦混交林为研究对象,研究土壤C、N、P化学计量特征。结果表明：（1）岷江冷杉及糙皮桦混交林土壤C、N含量最高,云杉林土壤N、P含量最低。不同林分间P含量差异显著（P<0.05）,不同土层间C、N含量差异均显著（P<0.05）。（2）云杉林土壤C ： N值显著高于其他林分,岷江冷杉及糙皮桦混交林土壤N ： P及C ： P高于其他林分。（3）海拔、土壤pH、容重与土壤含水量是影响土壤养分的重要因素。土壤C含量与N、P含量均显著相关（P<0.05）。总体来说,不同林分土壤化学计量特征具有显著差异,混交林土壤养分状况较纯林好,未来森林管理和植被建设中,可以通过选择合适的树种和提高树种多样性有效改善森林土壤质量。     

喀斯特典型地区烟管荚蒾AM真菌多样性研究

烟管荚蒾是喀斯特地区灌木丛的主要组成植物。以茂兰喀斯特森林为采样地点,对烟管荚蒾AM真菌进行了分离、鉴定与多样性分析,并对优势菌种进行初步的接种研究。结果表明:烟管荚蒾根系的菌根侵染率为82.1%,从根际土壤分离到AM真菌2属16种,球囊霉属(Glomus)7种,无梗囊霉属(Acaulospora)9种。优势种为根内球囊霉(Glomus intraradices)、皱壁无梗囊霉(Acaulospora rugosa)和刺无梗囊霉(A. spinosa)。优势菌种接种紫花苜蓿(Medicago sativa),促生作用明显,并显著提高了SOD、POD和CAT酶活性。该研究对于探讨喀斯特地区AM真菌的多样性与独特性,筛选优良的宿主植物和与之高效共生的AM真菌具重要意义。     

Losses of seeds of temperate trees to soil fungi: effects of habitat and host ecology

Evidence suggests that impacts of fungal pathogens on tree recruitment tend to be greater in the forest understory than in openings, and that shade-tolerant trees are less vulnerable than shade-intolerant species. To investigate the role that harmful soil fungi may have in reducing regeneration of temperate trees, we applied fungicide to buried seeds of matched pairs of species differing in their relative shade tolerance and/or successional status (Acer negundo versus Acer saccharum, Prunus virginiana versus Prunus serotina, and Pinus strobus versus Tsuga canadensis), in three habitats that differed in their degree of openness (old field, forest gap, and forest understory). Our results indicated that soil fungi reduced germination of A. negundo, P. virginiana, P. serotina. and T. canadensis, and reduced viability of ungerminated seeds of P. strobus; no significant effects of fungi on seeds of A. saccharum were detected. However, we found seeds were not less likely to survive following burial in forest understory than in gaps. As well, results for only one species pair (A. negundo versus A. saccharum) were consistent with the prediction that shade-intolerant or successional species should be more susceptible to fungal attack than mature forest species. These results contrast with other studies of temperate and especially tropical forest trees.     

A huge,undescribed soil ciliate (Protozoa: Ciliophora) diversity in natural forest stands of Central Europe

We investigated 12 natural forest stands in eastern Austria for soil ciliate diversity, viz., eight beech forests and two lowland and Pinus nigra forests each. The stands span a wide range of climatic (e.g., 543–1759 mm precipitation, 160–1035 m above sea-level) and abiotic (e.g., pH 4–7.4) factors. Samples were taken twice in autumn and late spring and analysed with the non-flooded Petri dish method. Species were identified in vivo, in silver preparations, and in the scanning electron microscope. A total of 233 species were found, of which 30 were undescribed, a surprising number showing our ignorance of soil ciliate diversity, even in Central Europe. Species number varied highly from 45 (acidic beech on silicate) to 120 (floodplain forest) and was strongly correlated with pH and overall habitat quality, as measured by climate, the C/P quotient (ratio of r-selected colpodean and k-selected polyhymenophorean ciliates), and the proportion of mycophagous ciliate species; multivariate analysis showed further important variables, viz., the general nutrient status (glucose, nitrogen, C/ N ratio) and microbial (urease) activity. The highest species number occurred in one of the two floodplain soils, supporting the intermediate disturbance hypothesis. The three main forest types could be clearly distinguished by their ciliate communities, using similarity indices and multidimensional scaling. Individual numbers varied highly from 135^–1 (lowland forest) to 10,925 ml^–1 (beech on silicate) soil percolate and showed, interestingly, a weak correlation with soil protozoan phospholipid fatty acids. Eight of the 30 new species found and a forgotten species, Arcuospathidium coemeterii (Kahl 1943) nov. comb., are described in detail, as examples of how species were recognized and soil protozoan diversity should be analyzed: Latispathidium truncatum bimicronucleatum, Protospathidium fusioplites, Erimophrya sylvatica, E. quadrinucleata, Paragonostomum simplex, Periholosticha paucicirrata, P. sylvatica, and Australocirrus zechmeisterae.     

缙云山4种林分土壤无机磷与活性铝的含量及分布

为探索不同林分对土壤中无机磷与活性铝的含量及分布的影响,以及无机磷与活性铝之间的相互关系,以在我国西南地区酸性土壤上的农林经营管理提供理论和实践依据。研究以缙云山广泛分布的4种林分类型：山莓、马尾松、楠竹和柑橘林土壤为对象,采用酸性土壤无机磷分级方法和铝试剂比色法测定了土壤剖面A、B和C层中各形态的无机磷与活性铝的含量,分析了不同林分土壤中无机磷和活性铝的含量和分布特征。结果表明,林分类型显著影响土壤中无机磷与活性铝的含量与分布,且铁磷(Fe-P)、交换态铝(Ex-Al)和羟基铝(Hy-Al)的含量和比例还受到土壤层次的影响。4种林分相比,山莓林能促进闭蓄态磷(O-P)的形成,而马尾松、楠竹和柑橘林则有利于Al-P、Fe-P和Ca-P的形成;柑橘林有利于低活性的腐殖酸铝(Al-AH)形成,而山莓、马尾松和楠竹林促进高活性的Ex-Al或Hy-Al溶出;Ex-Al、Al-P和Fe-P在土层的分布上有表层富集现象,而Hy-Al集中分布于B层。此外,土壤Ex-Al和Al-P与Fe-P之间,Hy-Al和Ca-P之间均呈显著(P<0.05)正相关。因此,林分类型显著影响土壤无机磷与活性铝的含...     

Exotic earthworm effects on hardwood forest floor, nutrient availability and native plants: a mesocosm study

A greenhouse mesocosm experiment, representing earthworm-free North American Acer-dominated forest floor and soil conditions, was used to examine the individual and combined effects of initial invasion by three European earthworm species (Dendrobaena octaedra, Lumbricus rubellus and Lumbricus terrestris) on the forest floor and upper soil horizons, N and P availability, and the mortality and biomass of four native understory plant species (Acer saccharum, Aquilegia canadensis, Aralia racemosa, and Carex pensylvanica). All the three earthworm species combined caused larger impacts on most variables measured than any single earthworm species. These included loss of O horizon mass, decreased thickness of the O horizon and increased thickness of the A horizon, and higher availability of N and P. The latter finding differs from field reports where nutrients were less available after invasion, and probably represents an initial transient increase in nutrient supply as earthworms consume and incorporate the O horizon into the A horizon. Earthworms also increased mortality of plants and decreased total mesocosm plant biomass, but here the impact of all the three earthworm species was no greater than that of L. terrestris and/or L. rubellus alone. This study corroborates field studies that European earthworm invasions alter North American forest ecosystem processes by initiating a cascade of impacts on plant community composition and soil properties.     

天山林区土壤真菌多样性及其群落结构

土壤真菌群落结构对森林生态系统功能的维持具有重要作用,目前对天山林区土壤微生物的种类和群落结构了解甚少。为了解天山不同植被类型下土壤真菌的群落动态及优势菌属,使用Illumina MiSeq高通量测序技术,研究天山林区根际土与非根际土中真菌群落组成及多样性。结果表明:(1)对有效序列进行OTU聚类(operational taxonomic unit)后共得到14121个OTUs,经注释划分为7个门、33个纲、109个目、255个科、444个属、677个种;(2)子囊菌门(Ascomycota)和担子囊菌门(Basidiomycota)是天山植物的优势菌门,灌丛中相对丰度较高的有帚枝霉属(Sarocladium)、鬼笔属(Lysurus)、Microidium;云杉林中相对丰度较高的属有镰刀属(Fusarium)、赤霉属(Gibberella)、丝盖伞属(Inocybe);(3)灌丛与云杉林土壤真菌的群落结构和丰富度有显著差异,灌丛土壤真菌的多样性和丰富度更高,云杉林中阴坡的土壤真菌丰富度较高而阳坡和林窗较低;(4)丝盖伞属(Inocybe)、被孢霉属(Mortierella)、赤霉属(Gibberella)、镰刀属(Fusarium)与云杉的生长可能具有密切的关系。本文推测,根际土壤真菌的多样性和丰富度较低可能是导致云杉幼苗成活率低等更新障碍的问题。