Tree endophytic fungi play an important role in reducing insect herbivory,either by repelling them or kill-ing them directly.Identifying which fungi show such activ-ity could lead to new environmentally friendly pesti...Tree endophytic fungi play an important role in reducing insect herbivory,either by repelling them or kill-ing them directly.Identifying which fungi show such activ-ity could lead to new environmentally friendly pesticides.In this study,the Mediterranean basin climate conditions are projected to harshen in the next decades,will increase vulnerability of tree species to pest invasions.Endophytic fungi were isolated from wood and leaves of Quercus pyr-enaica,Q.ilex and Q.suber and tested for virulence against adults of the mealworm beetle,Tenebrio molitor L.using a direct contact method.Only 3 of 111 sporulating isolates had entomopathogenic activity,all identified as Lecanicillium lecanii.The pathogenicity of L.lecanii on T.molitor resulted in a median lethal time(TL50)of 14-16 d.Compared with commercial products,L.lecanii caused faster insect death than the nematode Steinernema carpocapsae and nuclear polyhedrosis virus(no effect on T.molitor survival),and slower than Beauveria bassiana(TL50=5),Beauveria pseu-dobassiana(TL50=8d)and Bacillus thuriengensis(80%mortality first day after inoculation).Mortality was also accelerated under water stress,reducing TL50 by an addi-tional 33%.Remarkably,water stress alone had a comparable effect on mortality to that of L.lecanii isolates.This study confirms T.molitor as a good model insect for pathogenicity testing and agrees with management policies proposed in the EU Green Deal.展开更多
Global agriculture must urgently adopt a new approach to ensure adequate food production for the increasing population in the current context of adverse conditions,while prioritizing environmental sustainability.This ...Global agriculture must urgently adopt a new approach to ensure adequate food production for the increasing population in the current context of adverse conditions,while prioritizing environmental sustainability.This change requires innovative and environmentally conscious methods,such as symbiotic-microorganisms-based products.Among these organisms,the genus Trichoderma stands out,as these fungal endophytes reside within many plant species including those in the Brassicaceae family and interact with them positively.Brassicaceae encompass numerous taxa of special agricultural and food interest,such as those known as oilseed brassicas(OSBs).Among these group are crops for obtaining canola and mustard seeds,commonly used for oil and spices production,respectively.OSBs are of greater interest for food because they are rich source of vitamins and minerals,and have also a great antimicrobial,antioxidant and antitumor potential application.Therefore,the improvement of these plant species(or of their cultivation methods)may ultimately lead to an improvement in human food and,accordingly,human health.This progress could go hand in hand with the Trichoderma fungal genus,either based on transgenesis with some of their genes,or using these fungi to formulate and produce bioinoculants.In relation to transgenesis,the most widely studied are those based on Trichoderma genes encoding endochitinases and Kelch-like family proteins,in both cases to achieve an antifungal effect against pathogenic fungi.With regard to Trichoderma-based products,these can be aimed at promoting plant growth,protecting crops against pathogens by acting as biological control agents(BCAs),or even reducing contaminants in the soil,such as heavy metals.The purpose of the present literature review is to analyse and discuss most of the existing studies to date on the interaction between OSB crops and Trichoderma fungi.展开更多
The Mediterranean region in central Chile is experiencing a significant decrease in precipitation due to climate change and the dynamics of the El Nino Southern Oscillation(ENSO).Droughts have increased in recent deca...The Mediterranean region in central Chile is experiencing a significant decrease in precipitation due to climate change and the dynamics of the El Nino Southern Oscillation(ENSO).Droughts have increased in recent decades,~with the most severe and longest drought of the last millennium occurring since 2010 in central Chile.The impact of ongoing water scarcity is leading to significant drought-related declines in tree growth and forest dieback in the Mediterranean region.A deep understanding of how tree species respond to climate is crucial to accurately predict how forests will respond to climate change.We examined the growth responses to climate of three endemic and threatened tree species of the Mediterranean forests of central Chile,Nothofagus macrocarpa,Cryptocarya alba and Persea lingue,in a protected area.We observed that the growth of all three species was highly dependent on water availability and ENSO,and that the evergreen species C.alba and P.lingue increased their sensitivity to hydroclimate more than the deciduous species N.macrocarpa.These relationships were consistent across much of southern South America,highlighting the dependence of these species on water availability at large geographic scales.We found that there is a relationship between local water availability and ENSO that has intensified temporally and expanded geographically in recent decades.The xerophyllous species C.alba showed greater resistance and increasing resilience to severe droughts,while P.lingue and N.macrocarpa showed greater growth decline during droughts,possibly due to their preference for wetter environments.Our results highlight the crucial role of ENSO-driven water availability and drought in limiting tree growth and threatening the conservation of Mediterranean forests in central Chile.展开更多
Neighborhood competition is a critical driver of individual tree growth,and aboveground biomass(AGB)accumulation,which together play key roles in forest dynamics and carbon storage.Therefore,accurate biomass estimatio...Neighborhood competition is a critical driver of individual tree growth,and aboveground biomass(AGB)accumulation,which together play key roles in forest dynamics and carbon storage.Therefore,accurate biomass estimation is essential for understanding ecosystem functioning and informing forest management strategies to mitigate climate change.However,integrating neighborhood competition into biomass estimation models,particularly for young mixed forest stands,remains unexplored.In this study,we examined how incorporating neighborhood competition improves biomass prediction accuracy and how the influence of neighborhood competition differs between Scots pine(Pinus sylvestris L.)and Pyrenean oak(Quercus pyrenaica Willd.),as well as the relative contributions of intra-and interspecific competition to AGB.Our findings revealed that including neighborhood competition alongside tree size variables(DBH and total tree height)significantly improved the predictive accuracy of AGB models for Scots pine.This addition reduced the root mean square error(RMSE)by 14% and improved the model efficiency factor(MEF)by 15%.Furthermore,intraspecific competition in Scots pine slightly reduced AGB,whereas interspecific competition had a significant negative effect on AGB.In contrast,DBH alone was the best predictor of AGB for Pyrenean oak,as neighborhood competition did not improve model performance.Also,intra-and interspecific competition in Pyrenean oak had positive but nonsignificant effects on AGB.These findings highlight the important role of competition in biomass models and suggest species-specific approaches in competition dynamics to inform sustainable forest management and climate change adaptation strategies.展开更多
The use of mobile laser scanning to survey forest ecosystems is a promising,scalable technology to describe forest 3D structures at high resolution.To confirm the con-sistency in the retrieval of forest structural par...The use of mobile laser scanning to survey forest ecosystems is a promising,scalable technology to describe forest 3D structures at high resolution.To confirm the con-sistency in the retrieval of forest structural parameters using hand-held laser scanning(HLS),before operationalizing the method,confirming the data is crucial.We analyzed the per-formance of tree-level mapping based on HLS under differ-ent phenology conditions on a mixed forest in western Spain comprising Pinus pinaster and two deciduous species,Alnus glutinosa and Quercus pyrenaica.The area was surveyed twice during the growing season(July 2022)and once in the deciduous season(February 2022)using several scan-ning paths.Ground reference data(418 trees,15 snags)was used to calibrate the HLS data and to assess the influence of phenology when converting 3D data into tree-level attrib-utes(DBH,height and volume).The HLS-based workflow was robust at isolating tree positions and recognizing stems despite changes in phenology.Ninety-six percent of all pairs matched below 65 cm.For DBH,phenology barely altered estimates.We observed a strong agreement when comparing HLS-based tree height distributions.The values exceeded 2 m when comparing height measurements,confirming height data should be carefully used as reference in remote sensing-based inventories,especially for deciduous species.Tree volume was more precise for pines(r=0.95,and rela-tive RMSE=21.3–23.8%)compared to deciduous species(r=0.91–0.96,and relative RMSE=27.3–30.5%).HLS data and the forest structural complexity tool performed remark-ably,especially in tree positioning considering mixed forests and mixed phenology conditions.展开更多
Background: Understanding the role of species identity in interactions among individuals is crucial for assessing the productivity and stability of mixed forests over time. However, there is limited knowledge concerni...Background: Understanding the role of species identity in interactions among individuals is crucial for assessing the productivity and stability of mixed forests over time. However, there is limited knowledge concerning the variation in competitive effect and response of different species along climatic gradients. In this study, we investigated the importance of climate, tree size, and competition on the growth of three tree species: spruce(Picea abies), fir(Abies alba), and beech(Fagus sylvatica), and examined their competitive response and effect along a climatic gradient.Methods: We selected 39 plots distributed across the European mountains with records of the position and growth of 5,759 individuals. For each target species, models relating tree growth to tree size, climate and competition were proposed. Competition was modelled using a neighbourhood competition index that considered the effects of inter-and intraspecific competition on target trees. Competitive responses and effects were related to climate.Likelihood methods and information theory were used to select the best model.Results: Our findings revealed that competition had a greater impact on target species growth than tree size or climate. Climate did influence the competitive effects of neighbouring species, but it did not affect the target species? response to competition. The strength of competitive effects varied along the gradient, contingent on the identity of the interacting species. When the target species exhibited an intermediate competitive effect relative to neighbouring species, both higher inter-than intraspecific competitive effects and competition reduction occurred along the gradient. Notably, species competitive effects were most pronounced when the target species' growth was at its peak and weakest when growing conditions were far from their maximum.Conclusions: Climate modulates the effects of competition from neighbouring trees on the target tree and not the susceptibility of the target tree to competition. The modelling approach should be useful in future research to expand our knowledge of how competition modulates forest communities across environmental gradients.展开更多
Background:National and international institutions periodically demand information on forest indicators that are used for global reporting.Among other aspects,the carbon accumulated in the biomass of forest species mu...Background:National and international institutions periodically demand information on forest indicators that are used for global reporting.Among other aspects,the carbon accumulated in the biomass of forest species must be reported.For this purpose,one of the main sources of data is the National Forest Inventory(NFI),which together with statistical empirical approaches and updating procedures can even allow annual estimates of the requested indicators.Methods:Stand level biomass models,relating the dry weight of the biomass with the stand volume were developed for the five main pine species in the Iberian Peninsula(Pinus sylvestris,Pinus pinea,Pinus halepensis,Pinus nigra and Pinus pinaster).The dependence of the model on aridity and/or mean tree size was explored,as well as the importance of including the stand form factor to correct model bias.Furthermore,the capability of the models to estimate forest carbon stocks,updated for a given year,was also analysed.Results:The strong relationship between stand dry weight biomass and stand volume was modulated by the mean tree size,although the effect varied among the five pine species.Site humidity,measured using the Martonne aridity index,increased the biomass for a given volume in the cases of Pinus sylvestris,Pinus halepensis and Pinus nigra.Models that consider both mean tree size and stand form factor were more accurate and less biased than those that do not.The models developed allow carbon stocks in the main Iberian Peninsula pine forests to be estimated at stand level with biases of less than 0.2 Mg·ha^(-1).Conclusions:The results of this study reveal the importance of considering variables related with environmental conditions and stand structure when developing stand dry weight biomass models.The described methodology together with the models developed provide a precise tool that can be used for quantifying biomass and carbon stored in the Spanish pine forests in specific years when no field data are available.展开更多
Large in-stream wood (LW) is a critical component of riparian systems that increases heterogeneity of flow regimes and provides high quality habitat for salmonids and other fishes. We present four sampling-based ...Large in-stream wood (LW) is a critical component of riparian systems that increases heterogeneity of flow regimes and provides high quality habitat for salmonids and other fishes. We present four sampling-based methods to estimate two-dimensional LW for a 61-hectare river restoration project on the South Fork McKenzie River near Rainbow, OR (USA). We manually delineated LW area, from unoccupied aircraft systems (UAS) multispectral imagery for 40 randomly selected 51.46 m<sup>2</sup> hexagonal plots. Seven auxiliary variables were extracted from the imagery and imagery derivatives to be incorporated in four estimators by summarizing spectral statistics for each plot including Random forest (RF) classification of segmented imagery (Cohen’s kappa = 0.75, balanced accuracy = 0.86). The four estimators were: difference estimator, simple linear regression estimator with one auxiliary variable, general regression estimator with seven auxiliary variables, and simple random sample without replacement. We assessed variance of the estimators and found that the simple random sample without replacement produced the largest estimate for LW area and widest confidence interval (17,283 m<sup>2</sup>, 95% CI 10,613 - 23,952 m<sup>2</sup>) while the generalized regression approach resulted in the smallest estimate and narrowest confidence interval (16,593 m<sup>2</sup>, 95% CI 13,054 - 20,133 m<sup>2</sup>). These methods facilitate efficient estimates of critical habitat components, that are especially suited to efforts that seek to quantify large amounts of these components through time. When combined with traditional sampling methods, classified imagery acquired via UAS promises to enhance the temporal resolution of the data products associated with restoration efforts while minimizing the necessity for potentially hazardous field work.展开更多
RNA interference(RNAi)-based control technologies are gaining popularity as potential alternatives to synthetic fungicides in the ongoing effort to manage plant pathogenic fungi.Among these methods,spray-induced gene ...RNA interference(RNAi)-based control technologies are gaining popularity as potential alternatives to synthetic fungicides in the ongoing effort to manage plant pathogenic fungi.Among these methods,spray-induced gene silencing(SIGS)emerges as particularly promising due to its convenience and feasibility for development.This approach is a new technology for plant disease management,in which double-stranded RNAs(dsRNAs)targeting essential or virulence genes are applied to plants or plant products and subsequently absorbed by plant pathogens,triggering a gene silencing effect and the inhibition of the infection process.Spray-induced gene silencing has demonstrated efficacy in laboratory settings against various fungal pathogens.However,as research progressed from the laboratory to the greenhouse and field environments,novel challenges arose,such as ensuring the stability of ds RNAs and their effective delivery to fungal targets.Here,we provide a practical guide to SIGS for the control of plant pathogenic fungi.This guide outlines the essential steps and considerations needed for designing and assessing dsRNA molecules.It also addresses key challenges inherent to SIGS,including delivery and stability of ds RNA molecules,and how nanoencapsulation of dsRNAs can aid in overcoming these obstacles.Additionally,the guide underscores existing knowledge gaps that warrant further research and aims to provide assistance to researchers,especially those new to the field,encouraging the advancement of SIGS for the control of a broad range of fungal pathogens.展开更多
One of the most promising tools for the control of fungal plant diseases is spray-induced gene silencing(SIGS).In SIGS,small interfering RNA(siRNA)or double-stranded RNA(dsRNA)targeting essential or virulence-related ...One of the most promising tools for the control of fungal plant diseases is spray-induced gene silencing(SIGS).In SIGS,small interfering RNA(siRNA)or double-stranded RNA(dsRNA)targeting essential or virulence-related pathogen genes are exogenously applied to plants and postharvest products to trigger RNA interference(RNAi)of the targeted genes,inhibiting fungal growth and disease.However,SIGS is limited by the unstable nature of RNA under environmental conditions.The use of layered double hydroxide or clay particles as carriers to deliver biologically active dsRNA,a formulation termed BioClay^(TM),can enhance RNA durability on plants,prolonging its activity against pathogens.Here,we demonstrate that dsRNA delivered as BioClay can prolong protection against Botrytis cinerea,a major plant fungal pathogen,on tomato leaves and fruit and on mature chickpea plants.BioClay increased the protection window from 1 to 3 weeks on tomato leaves and from 5 to 10 days on tomato fruits,when compared with naked dsRNA.In flowering chickpea plants,BioClay provided prolonged protection for up to 4 weeks,covering the critical period of poding,whereas naked dsRNA provided limited protection.This research represents a major step forward for the adoption of SIGS as an eco-friendly alternative to traditional fungicides.展开更多
基金supported by LIFE project MYCORESTORE“Innovative use of mycological resources for resilient and productive Mediterranean forests threatened by climate change,LIFE18 CCA/ES/001110”projects VA178P23 and VA208P20 funded by JCYL(Spain),both co-financed by FEDER(UE)budget.
文摘Tree endophytic fungi play an important role in reducing insect herbivory,either by repelling them or kill-ing them directly.Identifying which fungi show such activ-ity could lead to new environmentally friendly pesticides.In this study,the Mediterranean basin climate conditions are projected to harshen in the next decades,will increase vulnerability of tree species to pest invasions.Endophytic fungi were isolated from wood and leaves of Quercus pyr-enaica,Q.ilex and Q.suber and tested for virulence against adults of the mealworm beetle,Tenebrio molitor L.using a direct contact method.Only 3 of 111 sporulating isolates had entomopathogenic activity,all identified as Lecanicillium lecanii.The pathogenicity of L.lecanii on T.molitor resulted in a median lethal time(TL50)of 14-16 d.Compared with commercial products,L.lecanii caused faster insect death than the nematode Steinernema carpocapsae and nuclear polyhedrosis virus(no effect on T.molitor survival),and slower than Beauveria bassiana(TL50=5),Beauveria pseu-dobassiana(TL50=8d)and Bacillus thuriengensis(80%mortality first day after inoculation).Mortality was also accelerated under water stress,reducing TL50 by an addi-tional 33%.Remarkably,water stress alone had a comparable effect on mortality to that of L.lecanii isolates.This study confirms T.molitor as a good model insect for pathogenicity testing and agrees with management policies proposed in the EU Green Deal.
基金This publication is part of the R&D project“PID2022-142403OA-I00(BIOCROPPING)”,funded by MCIN and“FEDER A way of doing Europe”.
文摘Global agriculture must urgently adopt a new approach to ensure adequate food production for the increasing population in the current context of adverse conditions,while prioritizing environmental sustainability.This change requires innovative and environmentally conscious methods,such as symbiotic-microorganisms-based products.Among these organisms,the genus Trichoderma stands out,as these fungal endophytes reside within many plant species including those in the Brassicaceae family and interact with them positively.Brassicaceae encompass numerous taxa of special agricultural and food interest,such as those known as oilseed brassicas(OSBs).Among these group are crops for obtaining canola and mustard seeds,commonly used for oil and spices production,respectively.OSBs are of greater interest for food because they are rich source of vitamins and minerals,and have also a great antimicrobial,antioxidant and antitumor potential application.Therefore,the improvement of these plant species(or of their cultivation methods)may ultimately lead to an improvement in human food and,accordingly,human health.This progress could go hand in hand with the Trichoderma fungal genus,either based on transgenesis with some of their genes,or using these fungi to formulate and produce bioinoculants.In relation to transgenesis,the most widely studied are those based on Trichoderma genes encoding endochitinases and Kelch-like family proteins,in both cases to achieve an antifungal effect against pathogenic fungi.With regard to Trichoderma-based products,these can be aimed at promoting plant growth,protecting crops against pathogens by acting as biological control agents(BCAs),or even reducing contaminants in the soil,such as heavy metals.The purpose of the present literature review is to analyse and discuss most of the existing studies to date on the interaction between OSB crops and Trichoderma fungi.
基金funded by Gobierno de Chile with the project“An atlas of droughts for Chile:1000 years of space-time changes and variations throughout the territory”(grant number FONDECYT 1181956).
文摘The Mediterranean region in central Chile is experiencing a significant decrease in precipitation due to climate change and the dynamics of the El Nino Southern Oscillation(ENSO).Droughts have increased in recent decades,~with the most severe and longest drought of the last millennium occurring since 2010 in central Chile.The impact of ongoing water scarcity is leading to significant drought-related declines in tree growth and forest dieback in the Mediterranean region.A deep understanding of how tree species respond to climate is crucial to accurately predict how forests will respond to climate change.We examined the growth responses to climate of three endemic and threatened tree species of the Mediterranean forests of central Chile,Nothofagus macrocarpa,Cryptocarya alba and Persea lingue,in a protected area.We observed that the growth of all three species was highly dependent on water availability and ENSO,and that the evergreen species C.alba and P.lingue increased their sensitivity to hydroclimate more than the deciduous species N.macrocarpa.These relationships were consistent across much of southern South America,highlighting the dependence of these species on water availability at large geographic scales.We found that there is a relationship between local water availability and ENSO that has intensified temporally and expanded geographically in recent decades.The xerophyllous species C.alba showed greater resistance and increasing resilience to severe droughts,while P.lingue and N.macrocarpa showed greater growth decline during droughts,possibly due to their preference for wetter environments.Our results highlight the crucial role of ENSO-driven water availability and drought in limiting tree growth and threatening the conservation of Mediterranean forests in central Chile.
基金the 2019 call for the predoctoral contract at the University of Valladolid cofinanced by Banco de Santander and projects‘CLU-2019-01-Unidad de Excelencia Instituto iuFOR’,‘PID2021-126275OB-C21’and‘PID2021-126275OB-C22’-Integrated Forest Management along complexity gradients(IMFLEX)‘MCIN/AEI/10.13039/501100011033/FEDER,UE’,which received financial support from the Regional Government of Castilla and León,Spainthe European Regional Development Fund(ERDF).
文摘Neighborhood competition is a critical driver of individual tree growth,and aboveground biomass(AGB)accumulation,which together play key roles in forest dynamics and carbon storage.Therefore,accurate biomass estimation is essential for understanding ecosystem functioning and informing forest management strategies to mitigate climate change.However,integrating neighborhood competition into biomass estimation models,particularly for young mixed forest stands,remains unexplored.In this study,we examined how incorporating neighborhood competition improves biomass prediction accuracy and how the influence of neighborhood competition differs between Scots pine(Pinus sylvestris L.)and Pyrenean oak(Quercus pyrenaica Willd.),as well as the relative contributions of intra-and interspecific competition to AGB.Our findings revealed that including neighborhood competition alongside tree size variables(DBH and total tree height)significantly improved the predictive accuracy of AGB models for Scots pine.This addition reduced the root mean square error(RMSE)by 14% and improved the model efficiency factor(MEF)by 15%.Furthermore,intraspecific competition in Scots pine slightly reduced AGB,whereas interspecific competition had a significant negative effect on AGB.In contrast,DBH alone was the best predictor of AGB for Pyrenean oak,as neighborhood competition did not improve model performance.Also,intra-and interspecific competition in Pyrenean oak had positive but nonsignificant effects on AGB.These findings highlight the important role of competition in biomass models and suggest species-specific approaches in competition dynamics to inform sustainable forest management and climate change adaptation strategies.
文摘The use of mobile laser scanning to survey forest ecosystems is a promising,scalable technology to describe forest 3D structures at high resolution.To confirm the con-sistency in the retrieval of forest structural parameters using hand-held laser scanning(HLS),before operationalizing the method,confirming the data is crucial.We analyzed the per-formance of tree-level mapping based on HLS under differ-ent phenology conditions on a mixed forest in western Spain comprising Pinus pinaster and two deciduous species,Alnus glutinosa and Quercus pyrenaica.The area was surveyed twice during the growing season(July 2022)and once in the deciduous season(February 2022)using several scan-ning paths.Ground reference data(418 trees,15 snags)was used to calibrate the HLS data and to assess the influence of phenology when converting 3D data into tree-level attrib-utes(DBH,height and volume).The HLS-based workflow was robust at isolating tree positions and recognizing stems despite changes in phenology.Ninety-six percent of all pairs matched below 65 cm.For DBH,phenology barely altered estimates.We observed a strong agreement when comparing HLS-based tree height distributions.The values exceeded 2 m when comparing height measurements,confirming height data should be carefully used as reference in remote sensing-based inventories,especially for deciduous species.Tree volume was more precise for pines(r=0.95,and rela-tive RMSE=21.3–23.8%)compared to deciduous species(r=0.91–0.96,and relative RMSE=27.3–30.5%).HLS data and the forest structural complexity tool performed remark-ably,especially in tree positioning considering mixed forests and mixed phenology conditions.
基金This publication is based upon work from COST Action CLIMO(CA15226) supported by COST (European Cooperation in Science and Technology)the UMBRACLIM project (PID2019-111781RB-I00)funded by the Spanish Ministry for Science and Innovation. Teresa Valor was contracted with a grant“Juan de la Cierva-Formaci on”(FJC2018-036673-I). Z.S. received funds from the grant no. APVV-20-0365 and from project TreeAdapt supported by the MPRV SR. Aitor Ameztegui is supported by a Serra-Húnter fellowship by the Generalitat de Catalunya。
文摘Background: Understanding the role of species identity in interactions among individuals is crucial for assessing the productivity and stability of mixed forests over time. However, there is limited knowledge concerning the variation in competitive effect and response of different species along climatic gradients. In this study, we investigated the importance of climate, tree size, and competition on the growth of three tree species: spruce(Picea abies), fir(Abies alba), and beech(Fagus sylvatica), and examined their competitive response and effect along a climatic gradient.Methods: We selected 39 plots distributed across the European mountains with records of the position and growth of 5,759 individuals. For each target species, models relating tree growth to tree size, climate and competition were proposed. Competition was modelled using a neighbourhood competition index that considered the effects of inter-and intraspecific competition on target trees. Competitive responses and effects were related to climate.Likelihood methods and information theory were used to select the best model.Results: Our findings revealed that competition had a greater impact on target species growth than tree size or climate. Climate did influence the competitive effects of neighbouring species, but it did not affect the target species? response to competition. The strength of competitive effects varied along the gradient, contingent on the identity of the interacting species. When the target species exhibited an intermediate competitive effect relative to neighbouring species, both higher inter-than intraspecific competitive effects and competition reduction occurred along the gradient. Notably, species competitive effects were most pronounced when the target species' growth was at its peak and weakest when growing conditions were far from their maximum.Conclusions: Climate modulates the effects of competition from neighbouring trees on the target tree and not the susceptibility of the target tree to competition. The modelling approach should be useful in future research to expand our knowledge of how competition modulates forest communities across environmental gradients.
文摘Background:National and international institutions periodically demand information on forest indicators that are used for global reporting.Among other aspects,the carbon accumulated in the biomass of forest species must be reported.For this purpose,one of the main sources of data is the National Forest Inventory(NFI),which together with statistical empirical approaches and updating procedures can even allow annual estimates of the requested indicators.Methods:Stand level biomass models,relating the dry weight of the biomass with the stand volume were developed for the five main pine species in the Iberian Peninsula(Pinus sylvestris,Pinus pinea,Pinus halepensis,Pinus nigra and Pinus pinaster).The dependence of the model on aridity and/or mean tree size was explored,as well as the importance of including the stand form factor to correct model bias.Furthermore,the capability of the models to estimate forest carbon stocks,updated for a given year,was also analysed.Results:The strong relationship between stand dry weight biomass and stand volume was modulated by the mean tree size,although the effect varied among the five pine species.Site humidity,measured using the Martonne aridity index,increased the biomass for a given volume in the cases of Pinus sylvestris,Pinus halepensis and Pinus nigra.Models that consider both mean tree size and stand form factor were more accurate and less biased than those that do not.The models developed allow carbon stocks in the main Iberian Peninsula pine forests to be estimated at stand level with biases of less than 0.2 Mg·ha^(-1).Conclusions:The results of this study reveal the importance of considering variables related with environmental conditions and stand structure when developing stand dry weight biomass models.The described methodology together with the models developed provide a precise tool that can be used for quantifying biomass and carbon stored in the Spanish pine forests in specific years when no field data are available.
文摘Large in-stream wood (LW) is a critical component of riparian systems that increases heterogeneity of flow regimes and provides high quality habitat for salmonids and other fishes. We present four sampling-based methods to estimate two-dimensional LW for a 61-hectare river restoration project on the South Fork McKenzie River near Rainbow, OR (USA). We manually delineated LW area, from unoccupied aircraft systems (UAS) multispectral imagery for 40 randomly selected 51.46 m<sup>2</sup> hexagonal plots. Seven auxiliary variables were extracted from the imagery and imagery derivatives to be incorporated in four estimators by summarizing spectral statistics for each plot including Random forest (RF) classification of segmented imagery (Cohen’s kappa = 0.75, balanced accuracy = 0.86). The four estimators were: difference estimator, simple linear regression estimator with one auxiliary variable, general regression estimator with seven auxiliary variables, and simple random sample without replacement. We assessed variance of the estimators and found that the simple random sample without replacement produced the largest estimate for LW area and widest confidence interval (17,283 m<sup>2</sup>, 95% CI 10,613 - 23,952 m<sup>2</sup>) while the generalized regression approach resulted in the smallest estimate and narrowest confidence interval (16,593 m<sup>2</sup>, 95% CI 13,054 - 20,133 m<sup>2</sup>). These methods facilitate efficient estimates of critical habitat components, that are especially suited to efforts that seek to quantify large amounts of these components through time. When combined with traditional sampling methods, classified imagery acquired via UAS promises to enhance the temporal resolution of the data products associated with restoration efforts while minimizing the necessity for potentially hazardous field work.
基金funded by the Spanish Ministry of Science,Innovation and Universities(Project No.PID2023-148417OAI00)the Spanish Ministry of Science and Innovation and by the European Union through the Next Generation Funds(Project No.PLEC2021-008076)+5 种基金funded by the Junta de Castilla y León through the projects“VAP208P20”,“VA178P23”the program“CLU-2019-01 and CL-EI-2021-05-iuFOR Unit of Excellence”co-funded by the European Regional Development Fundsupport from the European Union's Horizon Europe research and innovation programme under the MSCA agreement No.101068728PhD fellowships funded by Junta de Castilla y León(Orden EDU/601/2020 and Orden EDU/1508/2020)a Juan de la Cierva postdoctoral fellowship funded by MCIU/AEI/10.13039/501100011033 and“NextGenerationEU”/PRTR(Spain)。
文摘RNA interference(RNAi)-based control technologies are gaining popularity as potential alternatives to synthetic fungicides in the ongoing effort to manage plant pathogenic fungi.Among these methods,spray-induced gene silencing(SIGS)emerges as particularly promising due to its convenience and feasibility for development.This approach is a new technology for plant disease management,in which double-stranded RNAs(dsRNAs)targeting essential or virulence genes are applied to plants or plant products and subsequently absorbed by plant pathogens,triggering a gene silencing effect and the inhibition of the infection process.Spray-induced gene silencing has demonstrated efficacy in laboratory settings against various fungal pathogens.However,as research progressed from the laboratory to the greenhouse and field environments,novel challenges arose,such as ensuring the stability of ds RNAs and their effective delivery to fungal targets.Here,we provide a practical guide to SIGS for the control of plant pathogenic fungi.This guide outlines the essential steps and considerations needed for designing and assessing dsRNA molecules.It also addresses key challenges inherent to SIGS,including delivery and stability of ds RNA molecules,and how nanoencapsulation of dsRNAs can aid in overcoming these obstacles.Additionally,the guide underscores existing knowledge gaps that warrant further research and aims to provide assistance to researchers,especially those new to the field,encouraging the advancement of SIGS for the control of a broad range of fungal pathogens.
基金partially supported by the Australian Research Council Research Hub for Sustainable Crop Protection(IH190100022)funded by the Australian GovernmentNational Institute of Health(R35GM136379)+5 种基金National Science Foundation(IOS 2020731)United State Department of Agriculture(2021-67013-34258)the CIFAR‘Fungal Kingdom’fellowship to H.J.supported by MINECO(PID2019-110459RB-I00)MICINN(PLEC2021-008076)supported by an Advance Queensland Industry Research Fellowship。
文摘One of the most promising tools for the control of fungal plant diseases is spray-induced gene silencing(SIGS).In SIGS,small interfering RNA(siRNA)or double-stranded RNA(dsRNA)targeting essential or virulence-related pathogen genes are exogenously applied to plants and postharvest products to trigger RNA interference(RNAi)of the targeted genes,inhibiting fungal growth and disease.However,SIGS is limited by the unstable nature of RNA under environmental conditions.The use of layered double hydroxide or clay particles as carriers to deliver biologically active dsRNA,a formulation termed BioClay^(TM),can enhance RNA durability on plants,prolonging its activity against pathogens.Here,we demonstrate that dsRNA delivered as BioClay can prolong protection against Botrytis cinerea,a major plant fungal pathogen,on tomato leaves and fruit and on mature chickpea plants.BioClay increased the protection window from 1 to 3 weeks on tomato leaves and from 5 to 10 days on tomato fruits,when compared with naked dsRNA.In flowering chickpea plants,BioClay provided prolonged protection for up to 4 weeks,covering the critical period of poding,whereas naked dsRNA provided limited protection.This research represents a major step forward for the adoption of SIGS as an eco-friendly alternative to traditional fungicides.
