We quantified deviations in regional forest biomass from simple extrapolation of plot data by the biomass expansion factor method(BEF) versus estimates obtained from a local biomass model,based on large-scale empirica...We quantified deviations in regional forest biomass from simple extrapolation of plot data by the biomass expansion factor method(BEF) versus estimates obtained from a local biomass model,based on large-scale empirical field inventory sampling data.The sources and relative contributions of deviations between the two models were analyzed by the boosted regression trees method.Relative to the local model,BEF overestimated accumulative biomass by 22.12%.The predominant sources of the total deviation (70.94%) were stand-structure variables.Stand age and diameter at breast height are the major factors.Compared with biotic variables,abiotic variables had a smaller overall contribution (29.06%),with elevation and soil depth being the most important among the examined abiotic factors.Large deviations in regional forest biomass and carbon stock estimates are likely to be obtained with BEF relative to estimates based on local data.To minimize deviations,stand age and elevation should be included in regional forest-biomass estimation.展开更多
To determine the effects of different kinds of nitrogen fertilizer,especially high-efficiency slowrelease fertilizers,on soil pH,nitrogen(N)and microbial community structures in an acidic celery soil,four treatments(C...To determine the effects of different kinds of nitrogen fertilizer,especially high-efficiency slowrelease fertilizers,on soil pH,nitrogen(N)and microbial community structures in an acidic celery soil,four treatments(CK,no N fertilizer;NR,urea;PE,calcium cyanamide fertilizer;and SK,controlled-release N fertilizer)were applied,and soil pH,total soil N,inorganic N,and soil microbial biomass C were analyzed.Phospholipid fatty acids(PLFAs)were extracted and detected using the MIDI Sherlock microbial identification system.The PE treatment significantly improved soil pH,from 4.80 to>6.00,during the whole growth period of the celery,and resulted in the highest celery yield among the four treatments.After 14 d application of calcium cyanamide,the soil nitrate content significantly decreased,but the ammonium content significantly increased.The PE treatment also significantly increased soil microbial biomass C during the whole celery growth period.Canonical variate analysis of the PLFA data indicated that the soil microbial community structure in the CK treatment was significantly different from those in the N applied treatments after 49 d fertilization.However,there was a significant difference(P<0.05)in soil microbial community structure between the PE treatment and the other three treatments at the end of the experiment.Calcium cyanamide is a good choice for farmers to use on acidic celery land because it supplies sufficient N,and increases soil pH,microbial biomass and the yield of celery.展开更多
The recently discovered complete ammonia oxidizers comammox Nitrospira contain clades A and B that can establish an independent one-step nitrification process;however,little is known about their environmental drivers ...The recently discovered complete ammonia oxidizers comammox Nitrospira contain clades A and B that can establish an independent one-step nitrification process;however,little is known about their environmental drivers or habitat distributions in agricultural soils.Previous studies on comammox Nitrospira in paddy soils have mainly focused on small-scale samples,and there is a lack of multisite research on comammox Nitrospira in paddy soils.In this study,we conducted a survey of 36 paddy soils to understand the community structure,abundance,and diversity of comammox Nitrospira and the degree to which they are affected by environmental factors at a large scale.Comammox Nitrospira were found to be widely distributed among the paddy soils.The abundance of comammox Nitrospira clade A was mostly lower than that of clade B,whereas its diversity was mostly higher than that of clade B.Correlation analysis showed that multiple factors affected(P<0.05)the abundance of comammox Nitrospira,including soil pH,organic matter,total carbon,and total nitrogen,latitude,mean annual temperature,and mean annual precipitation.Moreover,there was a clear relationship between the comammox Nitrospira community and habitat,indicating that some amplicon sequence variants(ASVs)had a unique dominant position in specific habitats.Phylogenetic analysis showed that the ASVs of comammox Nitrospira clade A clustered with the known sequences in the paddy soils and were significantly different from the known sequences in other habitats,which may be related to the unique paddy field habitat.In contrast,comammox Nitrospira clade B showed no clear habitat dependence.These results support the wide distribution and high abundance of comammox Nitrospira in paddy soils and provide novel insights into nitrogen cycling and nutrient management in agricultural ecosystems.展开更多
Olfaction plays a crucial role for arthropods in foraging,mating,and oviposition.The odorant-binding protein(OBP)gene is considered one of the most important olfactory genes.However,little is known about its functions...Olfaction plays a crucial role for arthropods in foraging,mating,and oviposition.The odorant-binding protein(OBP)gene is considered one of the most important olfactory genes.However,little is known about its functions in predatory mites.Here,we used Neoseiulus barkeri,an important commercialized natural pest control,to explore the chemosensory characteristics of OBP.In this study,N.barkeri was attracted by methyl salicylate(MeSA)and showed higher crawling speeds under MeSA treatment.Then,we identified and cloned an OBP gene named Nbarobp2 and analyzed its expression profiles in the predatory mite.Nbarobp2 was 663 bp,was highly expressed in larval and nymphal stages,and was significantly upregulated in N.barkeri under MeSA treatment.Nbarobp2 encoded 202 amino acid residues with a molecular weight of 23 kDa(after removing the signal peptide).Sequence comparisons revealed that the OBPs in Arachnida shared 6 conserved cysteine sites,but were distinguishable from the OBPs of Insecta on the phylogenetic tree.RNA interference,Western blotting,and binding affinity assays further proved that Nbarobp2 was involved in volatile perception in predatory mites.This study shed light on the functional characteristics of OBPs in predatory mites,providing a new insight for better biological control.展开更多
基金supported by the Major Research Development Program of China(2016YFC0502704)National Science Foundation of China(31670645,31470578 and 31200363)+4 种基金National Forestry Public Welfare Foundation of China(201304205)Fujian Provincial Department of S&T Project(2013YZ0001-1,2015Y0083,2016Y0083,2016T3037 and 2016T3032)Key Laboratory of Urban Environment and Health of CAS(KLUEH-C-201701)Youth Innovation Promotion Association CAS(2014267)Key Program of the Chinese Academy of Sciences(KFZDSW-324)
文摘We quantified deviations in regional forest biomass from simple extrapolation of plot data by the biomass expansion factor method(BEF) versus estimates obtained from a local biomass model,based on large-scale empirical field inventory sampling data.The sources and relative contributions of deviations between the two models were analyzed by the boosted regression trees method.Relative to the local model,BEF overestimated accumulative biomass by 22.12%.The predominant sources of the total deviation (70.94%) were stand-structure variables.Stand age and diameter at breast height are the major factors.Compared with biotic variables,abiotic variables had a smaller overall contribution (29.06%),with elevation and soil depth being the most important among the examined abiotic factors.Large deviations in regional forest biomass and carbon stock estimates are likely to be obtained with BEF relative to estimates based on local data.To minimize deviations,stand age and elevation should be included in regional forest-biomass estimation.
基金financially supported by the Ningbo Agricultural Science and Education Project(2013NK29)the National Natural Science Foundation of China(41301251).
文摘To determine the effects of different kinds of nitrogen fertilizer,especially high-efficiency slowrelease fertilizers,on soil pH,nitrogen(N)and microbial community structures in an acidic celery soil,four treatments(CK,no N fertilizer;NR,urea;PE,calcium cyanamide fertilizer;and SK,controlled-release N fertilizer)were applied,and soil pH,total soil N,inorganic N,and soil microbial biomass C were analyzed.Phospholipid fatty acids(PLFAs)were extracted and detected using the MIDI Sherlock microbial identification system.The PE treatment significantly improved soil pH,from 4.80 to>6.00,during the whole growth period of the celery,and resulted in the highest celery yield among the four treatments.After 14 d application of calcium cyanamide,the soil nitrate content significantly decreased,but the ammonium content significantly increased.The PE treatment also significantly increased soil microbial biomass C during the whole celery growth period.Canonical variate analysis of the PLFA data indicated that the soil microbial community structure in the CK treatment was significantly different from those in the N applied treatments after 49 d fertilization.However,there was a significant difference(P<0.05)in soil microbial community structure between the PE treatment and the other three treatments at the end of the experiment.Calcium cyanamide is a good choice for farmers to use on acidic celery land because it supplies sufficient N,and increases soil pH,microbial biomass and the yield of celery.
基金supported by the National Natural Science Foundation of China(Nos.42077036 and 41877051)the Ningbo Municipal Science and Technology Bureau,China(No.202002N3079)。
文摘The recently discovered complete ammonia oxidizers comammox Nitrospira contain clades A and B that can establish an independent one-step nitrification process;however,little is known about their environmental drivers or habitat distributions in agricultural soils.Previous studies on comammox Nitrospira in paddy soils have mainly focused on small-scale samples,and there is a lack of multisite research on comammox Nitrospira in paddy soils.In this study,we conducted a survey of 36 paddy soils to understand the community structure,abundance,and diversity of comammox Nitrospira and the degree to which they are affected by environmental factors at a large scale.Comammox Nitrospira were found to be widely distributed among the paddy soils.The abundance of comammox Nitrospira clade A was mostly lower than that of clade B,whereas its diversity was mostly higher than that of clade B.Correlation analysis showed that multiple factors affected(P<0.05)the abundance of comammox Nitrospira,including soil pH,organic matter,total carbon,and total nitrogen,latitude,mean annual temperature,and mean annual precipitation.Moreover,there was a clear relationship between the comammox Nitrospira community and habitat,indicating that some amplicon sequence variants(ASVs)had a unique dominant position in specific habitats.Phylogenetic analysis showed that the ASVs of comammox Nitrospira clade A clustered with the known sequences in the paddy soils and were significantly different from the known sequences in other habitats,which may be related to the unique paddy field habitat.In contrast,comammox Nitrospira clade B showed no clear habitat dependence.These results support the wide distribution and high abundance of comammox Nitrospira in paddy soils and provide novel insights into nitrogen cycling and nutrient management in agricultural ecosystems.
基金This research was funded by the National Key R&D Program of China(2021YFC2600100)the National Natural Science Foundation of China(32072483,31901944)+2 种基金the Natural Science Foundation of Chongqing,China(cstc2020jcyj-msxmX0407)the Technology Innovation and Application Development Foundation of Chongqing,China(cstc2021jscx-lyjsAX0005)the Fundamental Research Funds for the Central Universities(SWUKQ22019).
文摘Olfaction plays a crucial role for arthropods in foraging,mating,and oviposition.The odorant-binding protein(OBP)gene is considered one of the most important olfactory genes.However,little is known about its functions in predatory mites.Here,we used Neoseiulus barkeri,an important commercialized natural pest control,to explore the chemosensory characteristics of OBP.In this study,N.barkeri was attracted by methyl salicylate(MeSA)and showed higher crawling speeds under MeSA treatment.Then,we identified and cloned an OBP gene named Nbarobp2 and analyzed its expression profiles in the predatory mite.Nbarobp2 was 663 bp,was highly expressed in larval and nymphal stages,and was significantly upregulated in N.barkeri under MeSA treatment.Nbarobp2 encoded 202 amino acid residues with a molecular weight of 23 kDa(after removing the signal peptide).Sequence comparisons revealed that the OBPs in Arachnida shared 6 conserved cysteine sites,but were distinguishable from the OBPs of Insecta on the phylogenetic tree.RNA interference,Western blotting,and binding affinity assays further proved that Nbarobp2 was involved in volatile perception in predatory mites.This study shed light on the functional characteristics of OBPs in predatory mites,providing a new insight for better biological control.
