Name: development of an individual-tree basal area increment model using a linear mixed-effects approach
Uploaded: 2020-07-03T13:00:00
Description: Watch this Scientific Journal Video about Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach at JoVE.com

Denne forskning blev finansieret af grundforskningsfondene for de centrale universiteter, tilskudsnummer 2019GJZL04. Vi takker professor Weisheng Zeng på Academy of Forest Inventory and Planning, National Forestry and Grassland Administration, Kina for at give adgang til data.

1. Udarbejdelse af data
<ol><li>Forbered modelleringsdata, som omfatter oplysninger om individuelle træer (art og diameter i brysthøjde ved 1,3 m) og plotoplysninger (hældning, aspekt og højde). I denne undersøgelse blev dataene indhentet fra den 8. (2009) og 9. (2014) kinesiske nationale skovbeholdning i Xinjiang-provinsen, nordvest Kina, som omfatter 21.898 observationer af 779 prøveområder. Disse prøveområder er firkantede med en størrelse på 1 Mu (kinesisk arealenhed svarende til 0,067 ha) og er systemat...

<ol>
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Et afgørende spørgsmål for udviklingen af mixed effects-modeller er at afgøre , hvilke parametre der kan behandles som tilfældige effekter , og hvilke der bør betragtes som faste virkninger34,35. Der er foreslået to metoder. Den mest almindelige tilgang er at behandle alle parametre som tilfældige effekter og derefter få den bedste model valgt af AIC, BIC, Loglik og LRT. Dette var den metode, der anvendes af vores undersøgelse35....

Sammenlignet med lige ældre monokultur har skovforvaltning af ujævne arter af blandede arter med flere mål fået øget opmærksomhed på det seneste1,2,3. Forudsigelse af forskellige forvaltningsalternativer er nødvendig for at formulere robuste skovforvaltningsstrategier, især for komplekse skovsorter af ujævne arter af blandede arter4. Modeller for skovvækst og udbytte er i vid udstrækning blevet anvendt til at forudsige udvikling og høst af træer eller bevoksning under forskellige forvaltningsordninger5,6,7. Skovvækst- og udbyttemodeller klassificeres i individuelle træmodeller, størrelsesklassemodeller og helstandsvækstmodeller6,7,8. Desværre er modeller i størrelsesklassen og helhedsmodeller ikke egnede til ujævne skove af blandede arter, som kræver en mere detaljeret beskrivelse for at støtte beslutningsprocessen for skovforvaltning. Af denne grund har individuelle trævækst- og udbyttemodeller fået øget opmærksomhed gennem de sidste par årtier på grund af deres evne til at lave forudsigelser for skovstande med en række arters sammensætninger, strukturer og forvaltningsstrategier9,10,11.
Almindelig mindst kvadratisk regression (OLS) er den mest anvendte metode til udvikling af individuelle trævækstmodeller12,13,14,15. Datasættene for individuelle trævækstmodeller , der gentagne gange er indsamlet over en bestemt periode på den samme prøvetagningsenhed (dvs. Den hierarkiske stokastiske struktur overtræder ols-regressions grundlæggende antagelser, nemlig uafhængige residualer og normalt distribuerede data med lige store afvigelser. Derfor giver brugen af OLS-regression uundgåeligt partiske estimater af standardfejlen i parameterestimater for disse data13,14.
Mixed effects-modeller er et effektivt værktøj til analyse af data med komplekse strukturer, f.eks. Mixed effects-modeller består af både faste komponenter, der er fælles for hele populationen, og tilfældige komponenter, som er specifikke for hvert prøveudtagningsniveau. Desuden tager modeller med blandede effekter højde for heteroscedasticitet og autokorrelation i tid og rum ved at definere ikke-diagonale varians-kovariansstrukturmatrixer17,18,19. Af denne grund er blandede effekter modeller blevet flittigt brugt i skovbrug, såsom i diameter-højde modeller20,21, krone modeller22,23, selvfortyndende modeller24,25, og vækstmodeller26,27.
Her var hovedformålet at udvikle en individuel-træ basal område tilvækst model ved hjælp af en lineær blandet effekt tilgang. Vi håber, at den blandede virkning kan anvendes i vid udstrækning.

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development of an individual-tree basal area increment model using a linear mixed-effects approach

Her har vi udviklet en individuel-træ model af 5-årige basal område stigninger baseret på et datasæt, herunder 21898 Picea asperata træer fra 779 prøve parceller beliggende i Xinjiang-provinsen, nordvest Kina. For at forhindre høje korrelationer mellem observationer fra den samme prøvetagningsenhed udviklede vi modellen ved hjælp af en lineær blandet effektmetode med tilfældig ploteffekt for at tage højde for stokastisk variation. Forskellige træ- og standniveauvariabler, såsom indekser for træstørrelse, konkurrence og tilstand på stedet, blev inkluderet som faste effekter for at forklare restvariationen. Desuden blev heteroscedasticitet og autokorrelation beskrevet ved at indføre variansfunktioner og autokorrelationsstrukturer. Den optimale lineære mixed effects-model blev bestemt af flere fit-statistikker: Akaikes informationskriterium, Bayesian-informationskriterium, logaritme sandsynlighed og en sandsynlighedsforholdstest. Resultaterne viste, at signifikante variabler af individuelle træ basale areal stigning var den omvendte omdannelse af diameter ved brysthøjde, det basale areal af træer større end emnet træet, antallet af træer pr hektar, og elevation. Desuden blev fejl i variansstrukturen modelleret mest af eksponentiel funktion, og autokorrelationen blev i væsentlig grad korrigeret af den autoregressive struktur (AR(1)). Udførelsen af den lineære mixed-effects model blev væsentligt forbedret i forhold til modellen ved hjælp af almindelige mindst firkanter regression.

Den grundlæggende model for forøgelse af basalområdet for P. asperata blev udtrykt som Ligning (7). Parameterestimaterne, de tilsvarende standardfejl og statistikkerne over manglende tilpasning fremgår af tabel 2. Restområdet er vist i figur 1. Udtalt heteroscedasticitet af residualerne blev observeret. <img alt="Equation 7" src="/files/ftp_upload/60827/60827eq7.jpg">(7)
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Watch this Scientific Journal Video about Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach at JoVE.com

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Mixed effects-modeller er fleksible og nyttige værktøjer til analyse af data med en hierarkisk stokastisk struktur inden for skovbrug og kan også bruges til at forbedre skovvækstmodellernes ydeevne betydeligt. Her præsenteres en protokol, der syntetiserer oplysninger vedrørende lineære blandede effektmodeller.

Udvikling af en individuel-Tree Basal Area Increment Model ved hjælp af en lineær mixed-effects tilgang

Here, we developed an individual-tree model of 5-year basal area increments based on a dataset including 21898 Picea asperata trees from 779 sample plots ...

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Spatial Multiobjective Optimization of Agricultural Conservation Practices using a SWAT Model and an Evolutionary Algorithm

Spatial Multiobjective Optimering af landbrugsprodukter Conservation Practices ved hjælp af en SWAT Model og en Evolutionary Algorithm

Finding the cost-efficient (i.e., lowest-cost) ways of targeting conservation practice investments for the achievement of specific water quality goals ...

A Semi-quantitative Approach to Assess Biofilm Formation Using Wrinkled Colony Development

En semi-kvantitativ tilgang til Vurdere biofilmdannelse Brug Rynket Colony Udvikling

Biofilms, or surface-attached communities of cells encapsulated in an extracellular matrix, represent a common lifestyle for many bacteria. Within a ...

Conversion of a Capture ELISA to a Luminex xMAP Assay using a Multiplex Antibody Screening Method

Omdannelse af en ELISA til en Luminex xMAP assay under anvendelse af en multiplex antistof screeningsmetode

The enzyme-linked immunosorbent assay (ELISA) has long been the primary tool for detection of analytes of interest in biological samples for both life ...

Cell Tracking Using Photoconvertible Proteins During Zebrafish Development

Cellesporing hjælp Photoconvertible proteiner under zebrafisk Development

Embryogenesis is a dynamic process that is best studied by using techniques that allow the documentation of developmental changes in vivo. The use of ...

Assessing Species-specific Contributions To Craniofacial Development Using Quail-duck Chimeras

Vurdere artsspecifikke bidrag til kraniofaciale Development Brug Quail-ænder kimærer

The generation of chimeric embryos is a widespread and powerful approach to study cell fates, tissue interactions, and species-specific contributions to ...

Development of a Quantitative Recombinase Polymerase Amplification Assay with an Internal Positive Control

Udvikling af en kvantitativ rekombinase Polymerase amplifikationsanalyse med et indre Positiv kontrol

It was recently demonstrated that recombinase polymerase amplification (RPA), an isothermal amplification platform for pathogen detection, may be used to ...

Using a Whole-mount Immunohistochemical Method to Study the Innervation of the Biliary Tract in Suncus murinus

Using a Whole-mount Immunohistochemical Method to Study the Innervation of the Biliary Tract in Suncus murinus

Brug af en helmonteret immunhistokemisk metode til at studere indervation af galdevejen i<em&gt; Suncus murinus</em

This work describes the whole-mount immunohistochemistry staining method in detail, using neurofilament protein antibody to label the innervation of the ...

Mass Spectrometry Analysis to Identify Ubiquitylation of EYFP-tagged CENP-A (EYFP-CENP-A)

Mass Spectrometry Analysis to Identify Ubiquitylation of EYFP-tagged CENP-A EYFP-CENP-A

Massespektrometri analyse til at identificere allestedsnærværendelation af EYFP-tagged CENP-A (EYFP-CENP-A)

Studying the structure and the dynamics of kinetochores and centromeres is important in understanding chromosomal instability (CIN) and cancer ...

Quantification of Cell-Substrate Adhesion Area and Cell Shape Distributions in MCF7 Cell Monolayers

Kvantificering af celleunderlagsadhæsionsområde og celleformfordelinger i MCF7-cellemonolag

The methods presented here quantify some parameters of confluent adherent cell monolayers from multiple appropriately stained confocal images: adhesion to ...