Institute of Forest Biometry and Informatics Georg-August-University Göttingen Ecophysiological forest stand modelling with XL/Java and GroIMP via internet Dirk Lanwert Institut of Forest Biometry and Informatics Göttingen 2007

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Today: two aspects? Ecophysiological forest stand model 1. which method and scale uses the model 2. how to use the growth model as via internet dirk lanwert Slide 2

Institute of Forest Biometry and Informatics Georg-August-University Göttingen 1. Aspect Method and scale of the model

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Triangle of plant models dirk lanwert Base relationship between: Structure Process -> core business of FSPM Scale: higher aggegration Where we can find classical forest yield models? Quelle: Buck-Sorlin, Kurth Slide 4

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Foresters Aim dirk lanwert how to include spatial information in forest yield models without increasing to much complexity computing time demand on underlying information Short: how to intergrate reasonable the competition between individual trees within a stand in tree growth prediction Quelle: Kurth Slide 5

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Eccophysiological models dirk lanwert : clasical position of FSPM-models are a way to occupy the upper part of the model triangle for the use in forest practice. Slide 6

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Our proposal: 1. a ecophysiological forest stand model with individual trees 2. the estimation of light conditions within the stand using needle the biomass distribution (competition) 3. the calculation of the photosynthesis production efficiency using a relation between: –unshaded condition and shaded condition (biomass as independent variable) dirk lanwert method from Sloboda & Pfreundt 1989 Slide 7

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Stand data requirements dirk lanwert initial data requirements: spatial stem parameter: –position, d1.3, height, spatial crown parameter: –position, height, diameter Slide 8

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Model calculation cycle dirk lanwert 1. biomass in 5 compartments main: needles 2. vertical distribution of needle biomass on tree segments 3. shading biomass for each tree segment 4. net-photosynthesis depending on shading biomass 5. respiration, allocation and growth biomass Slide 9

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Structure: main features a tree consists of vertical segments each segment owns his needle mass (beta distribution) segments are the calculation units dirk lanwert needle mass per segment Slide 10

Institute of Forest Biometry and Informatics Georg-August-University Göttingen shading needle biomass calculated is all needle mass inside a cone of 60° divided by squared distance of the owner segment dirk lanwert Slide 11

Institute of Forest Biometry and Informatics Georg-August-University Göttingen relative photosynthetic production maximum production rate = unshaded conditions above the tree top shading needle biomass within the cone as independant variable of a reduction function dirk lanwert Slide 12

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Why it is a good idea to use XL and GroIMP 1 private void kalkuliereExterneBeschattung(float winkel) 2 { 3 [ 4 s:Segment -ancestor-> best:Bestand, 5 ( s.nadelMasseGesamt > 0.0f && best.aktiv == true) ::> 6 { 7 s.externeBeschattung = 0.0f; 8 // Ermitteln der beschattenden Segmente(a) für das aktuelle Segment (s) 9 for ((* b:Baum (-->)* a:Segment, 10 ( s.getParent() != b && b.getLastChild() in cone(s, false, winkel)), 11 ( a.nadelMasseGesamt > 0.0f && a in cone(s, false, winkel)) *)) 12 { 13s[externeBeschattung] += ( a.nadelMasseGesamt 14 * b.lichtTransmissionsKoeffizient / (distanceSquared(a, s) 15 + b.kalkuliereNadelMasseVerteilungKorrekturTerm())); 16}; 17if (s.externeBeschattung > 0.0f) s[color] = F_BESCHATTET; 18} 19.] 20} dirk lanwert Slide 13

Institute of Forest Biometry and Informatics Georg-August-University Göttingen 2. Aspect Internet Connection

Institute of Forest Biometry and Informatics Georg-August-University Göttingen The idea: 1. the model should be accessible remotly via http 2. necessary stand description data can be included as http-post multipart/formdata. 3. calculation results will be stored in a file 4. the result file will delivered on demand via http-get dirk lanwert Short: the model as a web-service Slide 15

Institute of Forest Biometry and Informatics Georg-August-University Göttingen The solution Generalised stand desctiption (Forester stand description: VRML Format) sending program ( http, http-post) (multipart/formdata ) dirk lanwert Modell GroIMP Caller build in web- server (part of GroIMP) conecting the web-server (XL/Java class, input/output methods) understanding multipart/formdata (httpform package) understanding forester stand description (forester package) using tree data ( model code) Slide 16

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Easy integration of the web-server import de.grogra.imp.net.*de.grogra.imp.net … protected void startup() // Startmethode für den HTTP-Server-Betrieb. { super.startup(); HttpResponse resp = HttpResponse.get(workbench()); if (resp != null) { runLater(resp); } protected void run (Object info) { HttpResponse resp = (HttpResponse) info;//object with all recieved data StringBuffer buf = new StringBuffer();// textbuffer for the answer buf.append("url=" + server + "/open?" + modelout + ";" + filename + "\n"); // write answer resp.setContent("text/text", "UTF-8", buf.toString()); //answer format resp.send(true); //send answer init();// start model closeWorkbench(); } dirk lanwert Slide 17

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Easy integration of the web-server protected void run (Object info) { … // Read the form-data HttpMultipartFormData n1 = httpstartup.verarbeiteHttpInput(info); // Read Forester-Description foresterDescriptionIn = httpstartup.readForesterDescriptionFormfield(n1); // Create and send answer String filename = httpstartup.createAnswer(info,n1,foresterDescriptionIn); init(); // initialise model if(foresterDescriptionIn != null){ // specific part: start ersterSchritt(); // construct stand for (apply (simulationsPeriode)) kompletterJahresDurchlauf(); // run one year periode abspeichern(foresterDescriptionIn, ( modelOutputDir + filename) ); //specific part: end } closeWorkbench(); } dirk lanwert Slide 18

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Step 1: send the vrml file dirk lanwert Slide 19

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Step 2: Model calculation with GroIMP dirk lanwert stored in file:bestand_ stored in file:bestand_ Slide 20

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Step 3: deliver vrml file with resulting stand dirk lanwert ufgb985.forst.uni-goettingen.de:5880/open?deliverscene.gs scene=bestand_ scene=bestand_ Slide 21

Institute of Forest Biometry and Informatics Georg-August-University Göttingen Thank you for your attention and Ole Kniemeyer for GroIMP