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Modelling fuel loads of understorey vegetation and forest floor components in pine stands in NW Spain

Forest Ecosystems 2022年第6期9卷 775-789页

作者： Jose A.Vega Stefano Arellano-Perez Juan Gabriel Alvarez-Gonzalez Cristina Fernandez Enrique Jimenez Pedro Cuinas Jose María Fernandez-Alonso Daniel J.Vega-Nieva Fernando Castedo-Dorado Cecilia Alonso-Rego Teresa Fontúrbel Ana Daría Ruiz-Gonzalez Centro de Investigacion forestal de Lourizan PO Box 12736080PontevedraSpain Unidad de Gestion Ambiental y forestal Sostenible(UXAFORES) Departamento de Ingeniería AgroforestalEscuela Politecnica Superior de IngenieríaUniversidad de Santiago de CompostelaCampus Universitario s/n27002LugoSpain Facultad de Ciencias forestales Universidad Juarez del Estado de DurangoRío Papaloapan y Blvd.Durango s/nCol.Valle del Sur34120DurangoMexico departamento de ingeniería y Ciencias Agrarias Universidad de LeonCampus de Ponferrada24401PonferradaSpain

In this study,310 destructively sampled plots were used to develop two equation systems for the three main pine species in NW Spain(P.pinaster;P.radiata and P.sylvestris):one for estimating loads of understorey fuel components by size and condition(live and dead)and another one for forest floor fuels.Additive systems of equations were simultaneously fitted for estimating fuel loads using overstorey,understorey and forest floor variables as regressors.The systems of equations included both the effect of pine species and the effect of understorey compositions dominated by ferns-brambles or by woody species,due to their obvious structural and physiological differences.In general,the goodness-of-fit statistics indicated that the estimates were reasonably robust and accurate for all of the fuel fractions.The best results were obtained for total understorey vegetation,total forest floor and raw humus fuel loads,with more than 76%of the observed variability explained,whereas the poorest results were obtained for coarse fuel loads of understory vegetation with a 53%of observed variability explained.To reduce the overall costs associated with the field inventories necessary for operational use of the models,the additive systems were fitted again using only overstorey variables as potential regressors.Only relationships for fine(derstorey vegetation and total forest floor fuel loads were obtained,indicating the complexity of the forest overstorey-understorey and overstorey-forest floor relationships.Nevertheless,these models explained around 52%of the observed variability.Finally,equations estimating the total understorey vegetation and the total forest floor fuel loads based only on canopy cover were fitted.These models explained only 26%-32%of the observed variability;however,their main advantage is that although understorey vegetation in forested landscapes is largely invisible to remote sensing,canopy cover can be estimated with moderate accuracy,allowing for landscape-scale estimates of total fuel lo

关键词： Area-based approach Additive equation systems Live and dead fine fuel Pinus pinaster Pinus radiata Pinus sylvestris

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Disturbance and forest recovery in the Monarch Butterfly Biosphere Reserve,Mexico

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Journal of Forestry Research 2020年第5期31卷 1551-1566页

作者： Jose Lopez-Garcıa Rafael M.Navarro-Cerrillo Instituto de Geografıa Universidad Nacional Autonoma de MexicoCiudad UniversitariaC.P.04510 CoyoacanDFMexico Departamento de Ingenierıa Forestal Universidad de CordobaCampus de RabanalesCarretera Nacional IV km 39614014 CordobaSpain

Analysis of the change in forest cover is important to determine stand dynamics and the processes involved in disturbance and recovery.Forests of the core zone of the Monarch Butterfly Biosphere Reserve were studied using photo interpretation techniques,considering biennial changes between 1999 and 2013 and changes over the whole period of study 1999–2013.Error matrices were elaborated to determine the processes of change involved in both recovery and disturbance.The biennial changes for the whole period amounted to 2274 ha;343 ha accounted as degraded in more than one biennial period.The total changes in forest cover between 1999 and 2013 involved 4902 ha,out of which,2912 ha were affected by disturbance,and 1990 ha were recovered.For density and 2013 vegetation cover maps,the overall accuracy was 95.6%and 90.2%,respectively.By combining both maps,gradual processes were revealed that were not evident in separate analyses.This methodology is useful for the management and conservation of natural protected areas.

关键词： Illegal logging Forest density change Forest recovery Conifer forests Monarch Butterfly Biosphere Reserve

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Analysing changes in spatial point patterns:A proposal using data from a forest thinning experiment

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Forest Ecosystems 2022年第6期9卷 878-887页

作者： Christian Salas-Eljatib Joaquín Riquelme-Alarcon Pablo J.Donoso Diego Ponce Daniel P.Soto Centro de Modelacion y Monitoreo de Ecosistemas Escuela de Ingeniería ForestalUniversidad MayorSantiagoChile Vicerrectoría de Investigacion y Postgrado Universidad de La FronteraTemucoChile departamento de Silvicultura y Conservacion de la Naturaleza Universidad de ChileSantiagoChile Instituto de Bosques y Sociedad Universidad Austral de ChileValdiviaChile Corporacion Nacional forestal ValdiviaChile departamento de Ciencias Naturales y Tecnología Universidad de AysenCoyhaiqueChile

Spatial patterns reveal critical features at the individual and community levels.However,how to evaluate changes in spatial characteristics remains largely unexplored.We assess spatial changes in spatial point patterns by augmenting current statistical functions and indices.We fitted functions to describe unmarked and marked(tree size)spatial patterns using data from a large-scale silvicultural experiment in southern Chile.Furthermore,we compute the mingling index to represent spatial tree diversity.We proffer the pair correlation function difference before and after treatment to detect changes in the unmarked-point pattern of trees and the semivariogram-ratio to evaluate changes in the marked-point pattern.Our research provides a quantitative assessment of a critical aspect of forest heterogeneity:changes in spatial unmarked and marked-point patterns.The proposed approach can be a powerful tool for quantifying the impacts of disturbances and silvicultural treatments on spatial patterns in forest ecosystems.

关键词： Spatial diversity Marked-point process Spatial heterogeneity Conspecific Variable-density thinning Nothofagus

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Functional leaf and size traits determine the photosynthetic response of 10 dryland species to warming

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Journal of Plant Ecology 2016年第6期9卷 773-783页

作者： Enrique Valencia JoséL.Quero Fernando T.Maestre departamento de Biología y Geología Física y Química InorgánicaEscuela Superior de Ciencias Experimentales y TecnologíaUniversidad Rey Juan CarlosC/Tulipán s/n28933 MóstolesSpain departamento de ingeniería forestal Escuela Técnica Superior de Ingeniería Agronómica y de MontesUniversidad de Córdoba Campus de Rabanales CrtaN-IV km.396C.P.14071 CórdobaSpain

Aims Relatively few studies so far have assessed how ongoing global warming will affect the photosynthetic performance of dryland plant species.We evaluated the effects of warming on the photosynthetic rates of 10 species with contrasting functional attributes,and whether their functional traits modulated photosynthetic responses to warming.Methods A common garden experiment was conducted over 2 years with distinct environmental conditions(drier vs.wetter year).The experiment was designed as a randomized block design with two treatments:warming(control vs.~2.9℃ temperature increase)and species(Agropyron cristatum,Festuca ovina,Lygeum spartum,Medicago sativa,Plantago lanceolata,Psoralea bituminosa,Sanguisorba minor,Hedysarum coronarium,Dorycnium pentaphyllum and Phlomis herba-venti).We linked functional traits measurements with temporal variations in photosynthetic responses to warming.Important Findings In the drier year,warming increased photosynthetic rates at the beginning of the growing season,suggesting a modification in the growing period(earlier spring).In the wetter year,functional traits modulated photosynthetic responses to warming.Larger species with shorter leaves(e.g.M.sativa)had higher photosynthetic rates under warming compared to smaller species with larger leaves(e.g.F.ovina).Our results highlight the importance of(i)studying photosynthetic responses along different years and(ii)considering functional traits when evaluating photosynthetic responses to climate change,particularly in stressful environments such as drylands.

关键词： photosynthesis climate change Mediterranean functional traits open top chambers

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Distribution of Malpighia mexicana in Mexico and its implications for Barranca del Río Santiago

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Journal of Forestry Research 2021年第3期32卷 1095-1103页

作者： Martín Tena Meza Rafael MaNavarro-Cerrillo Diego Brizuela Torres Instituto de Botánica Centro Universitario de Ciencias Biológicas y AgropecuariasUniversidad de GuadalajaraMéxicoCamino Ramón Padilla Sánchez No.2100.Nextipac45200 ZapopanJaliscoMexico depto.ingeniería forestal Laboratorio de SelviculturaDendrocronología y Cambio ClimáticoDendrodatLab-ERSAFUniversidad de CórdobaCampus de RabanalesCtra.N-IVkm.39614071 CórdobaSpain departamento de Producción forestal Centro Universitario de CienciasBiológicas y AgropecuariasUniversidad de GuadalajaraMéxicoCamino Ramón Padilla Sánchez No.2100 Nextipac45200 ZapopanJaliscoMexico

Wild plants represent relatively unexplored resource of high economic potential,especially as an alternative to developing new crops and,even more relevant,for improving existing crops and contributing to nutrition and health.The wild species M alpighia mexicana(manzanita)has a wide tradition of food,medicinal and ornamental use in Mexico.It is part of the American-origin group of tropical shrubs that produce edible red fruits,such as A cerola,which is considered the most important natural source of vitamin C in the world.Given the role played by M.mexicana in Mexico,and particularly in Barranca del Río Santiago(Santiago River Canyon),we modelled its potential distribution in both geographical areas.We used species'records from databases,local herbaria and records collected by the authors as well as climatic variables representing long term average,variability and extreme conditions of temperature and precipitation.To fit the models we used the modelling algorithm Maxent and selected an adequate configuration by testing a range of model complexity settings.The results indicate a clear species preference for warm-dry tropical forest,most extensively in the Balsas river depression and the central valleys of Oaxaca.The probability of the species presence in the western region was also high,although the probability was also high for smaller surface areas,such as the region of Santiago river canyons,which are covered by warm-dry tropical forests.

关键词： Malpighia mexicana Maxent Warmdry tropical forest Río Santiago Genetic resources Ecological niche model Manzanita

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激光冲击工艺对6061-T6铝合金侵蚀性能的影响（英文）

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Transactions of Nonferrous Metals Society of China 2016年第6期26卷 1522-1530页

作者： J.IBARRA E.RODRíGUEZ O.JIMéNEZ G.GóMEZ-ROSAS M.FLORES J.VERDUZCO J.CHáVEZ Universidad de Guadalajara Departamento de Ingeniería de Proyectos Universidad de Guadalajara Departamento de Física Centro Universitario de Ciencias Exactas e Ingenierías

采用激光冲击工艺处理6061-T6铝合金,研究了二氧化硅砂对其侵蚀磨损性能的影响。其中冲击角为15°、30°、60°、90°,粒子速率为37和58 m/s,采用两种激光进行辐照。采用3D轮廓测量法表征了侵蚀形貌,并采用SEM研究其侵蚀机理。结果表明... 详细信息

采用激光冲击工艺处理6061-T6铝合金,研究了二氧化硅砂对其侵蚀磨损性能的影响。其中冲击角为15°、30°、60°、90°,粒子速率为37和58 m/s,采用两种激光进行辐照。采用3D轮廓测量法表征了侵蚀形貌,并采用SEM研究其侵蚀机理。结果表明,冲击角较小时,侵蚀磨损最大。侵蚀强度和侵蚀机理不受激光冲击工艺的影响,而与侵蚀的高应变速率有关。侵蚀图之间的差异是由于激光冲击工艺造成的表面粗糙度不同。最大质量损失和最大侵蚀深度分别出现在冲击角度为15°和30°时。最后,发现了明显的侵蚀机理的转移,从低角度的切割机制到90°时的凹坑形成。

关键词： 6061-T6铝合金侵蚀磨损激光冲击工艺

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development and screening of(Ca-P-Si-F)-PEO coatings for biodegradability control of Mg-Zn-Ca alloys

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Journal of Magnesium and Alloys 2022年第8期10卷 2220-2237页

作者： Lara Moreno Marta Mohedano Raul Arrabal Endzhe Matykina departamento de ingeniería Química y de Materiales Facultad de Ciencias QuímicasUniversidad Complutense de Madrid28040 MadridSpain

PEO coatings were developed on MgZnxCayalloys for biomedical applications using different treatment times and a novel transparent electrolyte containing Ca,P,Si and F.Surface characteristics and chemical composition of studied materials were evaluated using scanning electron microscopy,X-ray diffraction and optical metrology.Corrosion investigations were performed for uncoated and coated materials using potentiodynamic polarization,electrochemical impedance spectroscopy and hydrogen evolution measurements in three media(0.9wt.%NaCl,α-MEM and inorganic part ofα-MEM).Findings revealed that Zn-rich intermetallics favour the formation of large voids in the coatings.Ca,P,F and Si are successfully incorporated into the coatings.Coatings consist of crystalline phases(Mg O,Mg F_(2)and Ca,Si-rich compounds)and amorphous material.Aminoacids and organic components ofα-MEM solution accelerate corrosion of the bare substrates but have no significant influence on the corrosion resistance of coated specimens.Therefore,inorganicα-MEM can be considered as an appropriate medium for fast screening of PEO coatings.The relatively small amount of F content in the barrier layer facilitates early failure of the coatings,which show undercoating corrosion.Zn-rich intermetallic particles in the undercoating crevice induce a more aggressive corrosive environment and enhanced micro-galvanic couple effect with the Mg matrix.This leads to faster degradation of the coated alloys compared to the bare substrates.

关键词： Magnesium Biomaterials Plasma electrolytic oxidation Corrosion

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Photoelectrochemical CO_(2) electrolyzers: From photoelectrode fabrication to reactor configuration

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Journal of Energy Chemistry 2023年第10期85卷 455-480,I0012页

作者： Jose Antonio Abarca Guillermo Díaz-Sainz Ivan Merino-Garcia Angel Irabien Jonathan Albo departamento de ingenierías Química y Biomolecular Universidad de CantabriaETSIITAvenida de los Castros s/n39005 SantanderSpain

The photoelectrochemical conversion of CO_(2) into value-added products emerges as an attractive approach to alleviate climate change. One of the main challenges in deploying this technology is, however, the development and optimization of(photo)electrodes and photoelectrolyzers. This review focuses on the fabrication processes, structure, and characterization of(photo)electrodes, covering a wide range of fabrication techniques, from rudimentary to automated fabrication processes. The work also highlights the most relevant features of(photo)electrodes, with special emphasis on how to measure and optimize them. Finally, the review analyses the integration of(photo)electrodes in different photoelectrolyzer architectures, analyzing the most recent research work that comprises photocathode, photoanode,photocathode-photoanode, and tandem photoelectrolyzer configurations to ideally achieve self-sustained CO_(2) conversion systems. Overall, comprehensive guidelines are provided for future advancements in developing effective devices for CO_(2) conversion, bridging the gap towards the use of sunlight as the unique energy input and practical applications.

关键词： decarbonization CO_(2)photoelectroreduction (Photo)Electrodes Fabrication techniques Photoelectrolyzer configuration

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Environmental degradation through mining for energy resources:The case of the shrinking Laguna Santa Rosa wetland in the Atacama Region of Chile

Energy Geoscience

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Energy Geoscience 2022年第2期3卷 182-190页

作者： Mohammad Ayaz Alam Rosa Sepúlveda departamento de Geología Facultad de IngenieríaUniversidad de AtacamaAvenida Copayapu 485CopiapoRegion de AtacamaChile

As the world strives to replace fossil fuels with clean energy e reflected by global surge in the number of electric vehicles e the environmental impact of mining all the lithium(Li)needed to enable such a transformation has become a problem in its own right.In South America,the biggest problem is the excessive use of water in Li extraction process in one of the driest areas in the world.Apart from causing severe friction over water rights between local communities and mining companies,it puts enormous pressure on the region's fragile and poorly understood wetland ecosystems.Wetlands are one of the most threatened ecosystems on the Earth,despite their great importance as habitats for a vast number of species and corresponding to one of the most productive environments.Present work is the outcome of an investigation on Laguna Santa Rosa's(LSR)vulnerability resulting from ongoing metal mining operations in its surroundings that require a large volume of water extracted from local aquifers,in addition to a high evaporation rate in the area.This groundwater-dependent wetland will soon be further vulnerable with the commencement of water-intensive Li mining at Salar de Maricunga,with the extraction project already having an environmental impact study approved.Sustainability of this wetland protected under the Ramsar Convention and home to numerous wildlife species habiting this highland sector of the Andean Cordillera is vital for the associated ecosystems.The variation in the water surface area of LSR has been deciphered through the application of a Landsat-5 Thematic Mapper(TM)satellite image collection.This has been done both for the hydrological year 2016e2017 and 1993-2014 period.A decreasing trend in the water surface area of LSR,a hypersaline lake at the southern extreme of Salar de Maricunga,a salt flat in the Atacama Region of Chile,was observed through the study of satellite images between 1993 and 2014,showing shrinking of this wetland.However,this shrinking trend was punctuated by extreme rainfall and cons

关键词： Laguna Santa Rosa Salar de Maricunga Lithium Water Wetland Ecosystem

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Growth phenology adjusts to seasonal changes in water availability in coexisting evergreen and deciduous mediterranean oaks

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Forest Ecosystems 2023年第5期10卷 535-546页

作者： Filipe Campelo Alvaro Rubio-Cuadrado Fernando Montes Michele Colangelo Cristina Valeriano J.Julio Camarero department of Life Sciences University of CoimbraCalçada Martim de FreitasCoimbra3000-456Portugal departamento de Sistemas y Recursos Naturales Escuela Tecnica Superior de Ingeniería de MontesForestal y Del Medio NaturalUniversidad Politecnica de MadridCiudad Universitaria S/n28040MadridSpain Instituto Pirenaico de Ecología(IPE-CSIC) Avda.Montanana 1005E-50192ZaragozaSpain departamento de Dinamica y Gestion forestal Instituto de Ciencias Forestales(ICIFOR-INIA-CSIC)Ctra.La Coruna Km 7.528040MadridSpain Scuola di Scienze Agrarie ForestaliAlimentari e AmbientaliUniversita Della BasilicataViale Dell’Ateneo Lucano 1085100PotenzaItaly

Different leaf(evergreen vs.deciduous habit)and xylem(diffuse-vs.ring-porous wood)traits represent contrasting strategies to face seasonal changes in water availability and temperature.However,how contrasting leaf and xylem habits of coexisting tree species affect stem wood formation and tree-ring development remains poorly understood.Here,we investigated the spatio-temporal patterns of wood formation in two deciduous oaks(Quercus faginea and Quercus petraea)and two evergreen oaks(Quercus ilex and Quercus suber)coexisting in seasonally dry Mediterranean forests along an aridity gradient in Spain.We hypothesized that growth responses to drought and intra-and inter-annual growth patterns would differ between functional groups.We simulated intra-and interannual growth using a modified version of the Vaganov-Shashkin(VS)process-based,growth model.The VS model simulations were used to estimate growth changes under a high emission scenario(RCP 8.5)for the current distribution of the study oak species and to forecast their future performance under warm(4.8℃)conditions in the Iberian Peninsula.Our simulations indicate that climate warming would induce a shortening of the ringgrowth season and a reduction of radial growth in evergreen and deciduous Mediterranean oaks,particularly in dry sites from southern and eastern Iberia currently occupied by Q.ilex and Q.faginea.Evergreen oaks may better recover after dry periods than deciduous oaks by resuming growth after the summer drought.Low soil water availability in spring would be more detrimental to growth of deciduous oaks.Process-based growth models should be refined and validated to better forecast changes in tree growth as a function of climate.

关键词： Process-based growth model Quercus ilex Quercus suber Quercus faginea Quercus petraea Tree-ring growth

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