The life of Xuan Zhou, founding father of the Gastrodia elata cultivation and industry in China

Those familiar with Gastrodia elata Blume(Tianma,天麻)in China will most certainly recognise the name of Xuan Zhou(周铉),the first postgraduate student of Professor Zheng-Yi Wu(吴征镒),widely respected professor of botany and an academician of the Chinese Academy of Sciences(Peng et al.,2013).Xuan Zhou(abbreviated S.Chow in taxonomic citations,also Chou,Hsüan in Wade-Giles transliterations)(Fig.1)was born in Xinzheng,in the central Chinese Province of Henan on 4 May 1926.He graduated from Tongji University in 1951.He took part in and successfully passed the first national post-graduate examination held by the Chinese Academy of Sciences in 1956 and became a candidate for an Associate Doctor degree(equivalent to MSc)under the tutelage of Prof.Wu.

Different environmental factors drive tree species diversity along elevation gradients in three climatic zones in Yunnan,southern China

Elevational patterns of tree diversity are well studied worldwide.However,few studies have examined how seedlings respond to elevational gradients and whether their responses vary across climatic zones.In this study,we established three elevational transects in tropical,subtropical and subalpine mountain forests in Yunnan Province,southern China,to examine the responses of tree species and their seedlings to elevational gradients.Within each transect,we calculated species diversity indices and composition of both adult trees and seedlings at different elevations.For both adult trees and seedlings,we found that species diversity decreased with increasing elevation in both tropical and subalpine transects.Species composition showed significant elevational separation within all three transects.Many species had specific elevational preferences,but abundant tree species that occurred at specific elevations tended to have very limited recruitment in the understory.Our results highlight that the major factors that determine elevational distributions of tree species vary across climatic zones.Specifically,we found that the contribution of air temperature to tree species composition increased from tropical to subalpine transects,whereas the contribution of soil moisture decreased across these transects.

Estimating potential harvestable biomass for bioenergy from sustainably managed private native forests in Southeast Queensland, Australia

Background： Australia＇s energy future is at the crossroads and the role of renewable sources is in focus. Biomass from sustainably managed forests provide a significant opportunity for electricity and heat generation and production of liquid fuels. Australia has extensive native forests of which a significant proportion are on private land. However, there is limited knowledge on the potential capacity of this resource to contribute to the expansion of a biomass for bioenergy industry. In addition, there are concerns on how to reconcile biomass harvesting with environmental protection. Methods： We used regional ecosystem vegetation mapping for Queensland to stratify harvestable forests within the 1.8 m hectares of private native forests present in the Southeast Queensland bioregion in 2014. We used a dataset of 52,620 individual tree measurements from 541 forest inventory plots collected over the last 10 years. Tree biomass was estimated using current biomass allometric equations for Australia. Biomass potentially available from selective sawlog harvesting and silvicultural treatment across the bioregion was calculated and mapped. Results： Current sawlog harvesting extracts 41.4% of the standing tree biomass and a biomass for bioenergy harvest would retain on average 36% of felled tree biomass on site for the protection of environmental and fauna habitat values. The estimated area extent of harvestable private native forests in the bioregion in 2013 was 888,000 ha and estimated available biomass for bioenergy in living trees was 13.6 million tonnes （t）. The spotted gum （Corymbio citriodora subsp, variegata） forests were the most extensive, covering an area of 379,823 ha and with a biomass for bioenergy yield of 14.2 t-ha-1 （with approximately 11.2 t.ha-1 of the biomass harvested from silvicultural thinning and 3 t.ha-1 recovered from sawlog harvest residual）. Conclusions： Silvicultural treatment of private native forests in the Southeast Queensland bioregion, has the capacity to supply a large quantity of biomass for bioenergy. The availability of a biomass for bioenergy market, and integration of sawlog harvesting and silvicultural treatment operations, could provide land owners with additional commercial incentive to improve the management of private native forests. This could potentially promote restoration of degraded forests, ecological sustainability and continued provision of wood products.

Land use and dingo baiting are correlated with the density of kangaroos in rangeland systems

Rangelands worldwide have been subject to broadscale modification,such as widespread predator control,intro-duction of permanent livestock water and altered vegetation to improve grazing.In Australia,these landscape changes have resulted in kangaroos(i.e.large macropods)populations increasing over the past 200 years.Kan-garoos are a key contributor to total grazing pressure and in conjunction with livestock and feral herbivores have been linked to land degradation.We used 22 years of aerial survey data to investigate whether the density of 3 macropod species in the southern rangelands of Western Australia was associated with:(i)land use,including type of livestock,total livestock,density of feral goats,type of land tenure,and kangaroo commercial harvest effort;(ii)predator management,including permitted dingo control effort,estimated dingo abundance,and presence of the State Barrier Fence(a dingo exclusion fence);and(iii)environmental variables:ruggedness,rainfall,fractional cover,and total standing dry matter.Red kangaroos(Osphranter rufus)were most abundant inflat,open vegetation,on pastoral land,where area permitted for dingo control was high,and numbers were positively associated with antecedent rainfall with a 12-month delay.Western grey kangaroos(Macropus fuliginosus)were most abundant onflat,agricultural land,but less abundant in areas with high permitted dingo control.Euros(Osphranter robustus)were most abundant in rugged pastoral land with open vegetation,where permitted dingo control was high.While environmental variables are key drivers of landscape productivity and kangaroo populations,anthropogenic factors such as land use and permitted dingo control are strongly associated with kangaroo abundance.

An investigation on the best-fit models for sugarcane biomass estimation by linear mixedeffect modelling on unmanned aerial vehicle-based multispectral images:A case study of Australia

Due to the worldwide population growth and the increasing needs for sugar-based products,accurate estimation of sugarcane biomass is critical to the precise monitoring of sugarcane growth.This research aims to find the imperative predictors correspond to the random and fixed effects to improve the accuracy of wet and dry sugarcane biomass estimations by integrating ground data and multi-temporal images from Unmanned Aerial Vehicles(UAVs).The multispectral images and biomass measurements were obtained at different sugarcane growth stages from 12 plots with three nitrogen fertilizer treatments.Individual spectral bands and different combinations of the plots,growth stages,and nitrogen fertilizer treatments were investigated to address the issue of selecting the correct fixed and random effects for the modelling.A model selection strategy was applied to obtain the optimum fixed effects and their proportional contribution.The results showed that utilizing Green,Blue,and Near Infrared spectral bands on models rather than all bands improved model performance for wet and dry biomass estimates.Additionally,the combination of plots and growth stages outperformed all the candidates of random effects.The proposed model outperformed the Multiple Linear Regression(MLR),Generalized Linear Model(GLM),and Generalized Additive Model(GAM)for wet and dry sugarcane biomass,with coefficients of determination(R2)of 0.93 and 0.97,and Root Mean Square Error(RMSE)of 12.78 and 2.57 t/ha,respectively.This study indicates that the proposed model can accurately estimate sugarcane biomasses without relying on nitrogen fertilizers or the saturation/senescence problem of Vegetation Indices(VIs)in mature growth stages.

Changes in the ground surface temperature in permafrost regions along the Qinghaie-Tibet engineering corridor from 1900 to 2014:A modified assessment of CMIP6

Numerous studies were published in the last two decades to evaluate and project the permafrost changes in its thermal state,mainly based on the soil temperature datasets from the Coupled Model Intercomparison Project(CMIP),and discuss the impacts of permafrost changes on regional hydrological,ecological and climatic systems and even carbon cycles.However,limited monitored soil temperature data are available to validate the CMIP outputs,resulting in the over-projection of future permafrost changes in CMIP3 and CMIP5.Moreover,future permafrost changes in CMIP6,particularly over the QinghaieTibet Plateau(QTP),where permafrost covers more than 40%of its territory,are still unknown.To address this gap,we evaluated and calibrated the monthly ground surface temperature(GST;5 cm below the ground surface),which was often used as the upper boundary to simulate and project permafrost changes derived from 19 CMIP6 Earth System Models(ESMs)against in situ measurements over the QTP.We generated the monthly GST series from 1900 to 2014 for five sites based on the linear calibration models and validated them through the three other sites using the same calibration methods.Results showed that all of the ESMs could capture the dynamics of in situ GST with high correlations(r>0.90).However,large errors were detected with a broad range of centred root-mean-square errors(1.14-4.98℃).The Top 5 model ensembles(MME5)performed better than most individual ESMs and averaged multi-model ensembles(MME19).The calibrated GST performed better than the GST obtained from MME5.Both annual and seasonal GSTs exhibited warming trends with an average annual rate of 0.04℃ per decade in the annual GST.The average seasonal warming rate was highest in winter and spring and lowest in summer.This reconstructed GST data series could be used to simulate the long-term permafrost temperature over the QTP.