Sand-fflled splash cups were used to study the erosive power of rainfall and throughfall in the humid subtropics of Southeast China. The splash cup measurements yielded precise and reproducible results under both open field conditions and forest vegetation. The splash cups were exposed to specific forest stands of different ages and to selected species （Schima superba, Castanopsis eyrei, Daphniphyllum oldhamii, Lithocarpus glaber） in the Gutianshan （古田山） National Nature Reserve （GNNR）. The results of the measurements under forest vegetation show that the erosive power of throughfall drops to be 2.59 times higher compared to the open field. This accentuates the importance of shrub, herb and litter layers in forest ecosystems to protect the soil against erosion. Coalescing drops from leaves and branches （drips） are responsible for this notable gain in erosive power. Moreover, differences in sandloss between the investigated tree species （deciduous, evergreen） revealed that the erosion potential and the spatial heterogeneity of throughfall are species-specific. This highlights the importance of selecting specific species for afforestation projects considering the prevention of soil erosion.
Pestalotiopsis is a taxonomically confused,pathogenic and chemically creative genus requiring a critical reexamination using a multi-gene phylogeny based on ex-type and ex-epitype cultures.In this study 40 isolates of Pestalotiopsis,comprised of 28 strains collected from living and dead plant material of various host plants from China were studied by means of morphology and analysis of ITS,β–tubulin and tef1 gene sequence data.Based on molecular and morphological data we describe 14 new species(Pestalotiopsis asiatica,P.chinensis,P.chrysea,P.clavata,P.diversiseta,P.ellipsospora,P.inflexa,P.intermedia,P.linearis,P.rosea,P.saprophyta,P.umberspora,P.unicolor and P.verruculosa)and three species are epitypified(P.adusta,P.clavispora and P.foedans).Of the 10 gene regions(ACT,β-tubulin,CAL,GPDH,GS,ITS,LSU,RPB 1,SSU and tef1)utilized to resolve cryptic Pestalotiopsis species,ITS,β–tubulin and tef1 proved to be the better markers.The other gene regions were less useful due to poor success in PCR amplification and/or in their ability to resolve species boundaries.As a single gene tef1 met the requirements for an ideal candidate and functions well for species delimitation due to its better species resolution and PCR success.Althoughβ-tubulin showed fairly good differences among species,a combination of ITS,β-tubulin and tef1 gene data gave the best resolution as compared to single gene analysis.This work provides a backbone tree for 22 ex-type/epitypified species of Pestalotiopsis and can be used in future studies of the genus.
Aims The aim of our research was to understand small-scale effects of topography and soil fertility on tree growth in a forest biodiversity and ecosystem functioning(BEF)experiment in subtropical SE China.Methods Geomorphometric terrain analyses were carried out at a spatial resolution of 5×5 m.Soil samples of different depth increments and data on tree height were collected from a total of 566 plots(667 m2 each).The soils were analyzed for carbon(soil organic carbon[SOC]),nitrogen,acidity,cation exchange capacity(CEC),exchangeable cations and base saturation as soil fertility attributes.All plots were classified into geomorphological units.Analyses of variance and linear regressions were applied to all terrain,soil fertility and tree growth attributes.Important Findings In general,young and shallow soils and relatively small differences in stable soil properties suggest that soil erosion has truncated the soils to a large extent over the whole area of the experiment.This explains the concurrently increasing CEC and SOC stocks downslope,in hollows and in valleys.However,colluvial,carbon-rich sediments are missing widely due to the convexity of the footslopes caused by uplift and removal of eroded sediments by adjacent waterways.The results showed that soil fertility is mainly influenced by topography.Monte-Carlo flow accumulation(MCCA),curvature,slope and aspect significantly affected soil fertility.Furthermore,soil fertility was affected by the different geomorphological positions on the experimental sites with ridge and spur positions showing lower exchangeable base cation contents,especially potassium(K),due to leaching.This geomorphological effect of soil fertility is most pronounced in the topsoil and decreases when considering the subsoil down to 50 cm depth.Few soil fertility attributes affect tree height after 1-2 years of growth,among which C stocks proved to be most important while pH_(KCl)and CEC only played minor roles.Nevertheless,soil acidity and a high proportion of Al on the exchange complex affe
Aims Plant diversity has been linked to both increasing and decreasing levels of arthropod herbivore damage in different plant communities.So far,these links have mainly been studied in grasslands or in artificial tree plantations with low species richness.Furthermore,most studies provide results from newly established experimental plant communities where trophic links are not fully established or from stands of tree saplings that have not yet developed a canopy.Here,we test how tree diversity in a species-rich subtropical forest in China with fully developed tree canopy affects levels of herbivore damage caused by different arthropod feeding guilds.Methods We established 27 plots of 30×30 m area.The plots were selected randomly but with the constraint that they had to span a large range of tree diversity as required for comparative studies in contrast to sample surveys.We recorded herbivore damage caused by arthropod feeding guilds(leaf chewers,leaf skeletonizers and sap feeders)on canopy leaves of all major tree species.Important Findings Levels of herbivore damage increased with tree species richness and tree phylogenetic diversity.These effects were most pronounced for damage caused by leaf chewers.Although the two diversity measures were highly correlated,we additionally found a significant interaction between them,whereby species richness increased herbivory mostly at low levels of phylogenetic diversity.Tree species with the lowest proportion of canopy leaf biomass in a plot tended to suffer the highest levels of herbivore damage,which is in contrast to expectations based on the resource concentration hypothesis.Our results are in agreement with expectations of the dietary mixing hypothesis where generalist herbivores with a broad spectrum of food plants benefit from increased resource diversity in tree species-rich forest patches.
Aims Mycorrhizal fungi can re-distribute nutrients among plants through formation of underground common mycorrhizal networks and therefore may alter interspecific plant competition.However,the effect of ectomycorrhizal(EM)fungi on interspecific plant competition in subtropical forests is poorly understood.In this study,we investigated the effects of EM fungal identity and diversity on the outcome of interspecific competition of plant species in relation to different successional stages in a Chinese subtropical forest.Materials and Methods This study selected four woody plant species,i.e.a pioneer tree Pinus massoniana,a late-pioneer tree Quercus serrata,a midsuccessional tree Cyclobalanopsis glauca and a late-successional tree Lithocarpus glaber in a Chinese subtropical forest.The outcomes of interspecific competition were investigated in the seedlings of three plant pairs,i.e.between Cy.glauca and Pin.mas-soniana,between Q.serrata and Pin.massoniana,and between Li.glaber and Q.serrata in a pot experiment.In the Cy.glauca-Pin.massoniana combination,plants in monoculture and two-species mixture were uninoculated or inoculated with EM fungi Paxillus involutus,Pisolithus tinctorius,Cenococcum geophilum,Laccaria bicolor and a mixture of these four fungal species.In the Q.ser-rata-Pin.massoniana and Li.glaber-Q.serrata combinations,plants in monocultures and two-species mixtures were uninoculated or inoculated with EM fungi Pis.tinctorius,Ce.geophilum,La.bicolor and a mixture of these three fungal species.EM root colonization rate and seedling biomass of each plant species were measured,and the outcomes of interspecific competition were estimated using competitive balance index after 6-month cultivation.Important Findings All EM fungal inoculation significantly promoted a competitive ability of the mid-successional tree Cy.glauca over the pioneer tree Pin.massoniana compared with the uninoculated control treatment,and the extent to which EM fungi affected the outcome of interspecific competition was dependent on EM fu
