similar to: VEGAN: R functions for vegetation ecologists

Displaying 20 results from an estimated 1000 matches similar to: "VEGAN: R functions for vegetation ecologists"

2003 Dec 15
0
packages for ecologists - summary
Dear R user, I asked for packages which should be mentioned in a ecological related presentation of R and would like to summarize the replies. First of all E. Paradis pointed out, that he would prefer to see R presented in a different way, please read his whole reply https:// www.stat.math.ethz.ch/pipermail/r-help/2003-December/041951.html. Packages which
2001 Feb 17
0
Krebs for R (was Re: canonical correspondence analysis)
R-ecologists: Anyone wanting to create a Krebs package for R can do so using the C-source code avalaible at: ftp://gause.biology.ualberta.ca/pub/jbrzusto/krebs/source.zip Barry J. Cooke Current mailing address: Ph.D. Candidate 3971 NW 23 Circle Environmental Biology and Ecology Gainesville, Florida, USA Department of Biological Sciences 32605
2009 May 27
1
vegan metaMDS question
The design decision in metaMDS says that it uses: Minchin, P.R. (1987) An evaluation of relative robustness of techniques for ecological ordinations. Vegetatio 71, 145-156. This is the paper that I found by the same name. Is this the correct reference? Minchin, Peter R.1987. An Evaluation of the Relative Robustness of Techniques for Ecological Ordination. Vegetatio. Vol. 69, No. 1/3: 89-107.
2010 Apr 13
1
vegan (ordisurf): R² for smoothed surfaces
Dear r-helpers, I just read in an article by Virtanen et al. (2006) where vegetation-environment relationships are studied by fitting smoothed surfaces on an NMDS ordination using GAMs (Wood 2000). The authors describe, that they used R? as goodness-of-fit statistic, which they compare to the R? of fitted vectors. Calculations were carried out using the package vegan (Oksanen). I know that I can
2012 Jul 27
1
labeling loading vectors in vegan
Hello, I am using vegan to do an NMDS plot and I would like to suppress the labels for the loading vectors. Is this possible? Alternatively, how can I avoid overlap? Many thanks for the help. Example code: #perform NMDS using metaMDS() function spe.nmds<-metaMDS(data, distance='bray',k=2 , engine = "isoMDS", autotransform=F, trymax=1000) #calculate the loading (i.e.,
2013 Sep 06
1
Fwd: calculating dissimilarity index of islands (vegan and betapart)
Dear List, This is Elaine, a postgraduate studying in bird distributions in East Asia. I want to calculate Simpson dissimilarity index, based on a presence/absence matrix of bird species in islands in East Asia. (matrix row: 36 islands/matrix column: species ID) (R package vegan to make NMDS and R package betapart) In most papers using vegan for NMDS and betapart for dissimilarity
2007 Aug 24
1
Adding new points to a metaMDS ordination ("vegan" pkg)
Hi, I've been using R for a while now but I've got a problem with metaMDS (in the vegan package) that I can't quite figure out. I have a set of proportion data (from 0-1, rows sum to 1) that I apply metaMDS to using the command: nMDS.set=metaMDS(sqrt(test.set),distance="euclidean",k=3,zerodist="add",autotransform=FALSE) I am using a squared-chord distance
2010 Nov 12
1
repeated measure test
Hi, This is a question regarding technique rather than an R specific issue. I have been asked to evaluate a 30+ year long term continuous survey of bird presence/absence data that has an associated ocular estimate of the vegetation community percent coverage. The data are organized by subpopulations (5), and by year ( 1991 - present). We are interested in gaining understanding on whether bird
2013 Apr 26
1
NMDS in Vegan: problems in stressplot, best solution
Hello, I can draw a basic stress plot for NMDS with the following code in package Vegan. > stressplot(parth.mds, parth.dis) When I try to specify the line and point types, it gives me error message. > stressplot(parth.mds, parth.dis, pch=1, p.col="gray", lwd=2, l.col="red") Error in plot.xy(xy, type, ...) : invalid plot type In the above code, if I removed line type,
2009 Sep 09
2
"predict"-fuction for metaMDS (vegan)
Dear r-Community, Step1: I would like to calculate a NMDS (package vegan, function metaMDS) with species data. Step2: Then I want to plot environmental variables over it, using function envfit. The Problem: One of these environmental variables is cos(EXPOSURE). But for flat releves there is no exposure. The value is missing and I can't call it 0 as 0 stands for east and west. Therefore I
2008 Apr 14
1
Vegan R^2 and tau values for metaMDS
I am using the function metaMDS with jaccard distances to ordinate a set of constituent by site matrix. I can post this data if it would be helpful, but it is large to include in an email. I can also provide reproducable code if necessary. I would like to get an R^2 value for the axes of the ordination configuration that I get with metaMDS in the vegan package is there a way to do this- is it
2012 May 09
1
reception of (Vegan) envfit analysis by manuscript reviewers
I'm getting lots of grief from reviewers about figures generated with the envfit function in the Vegan package. Has anyone else struggled to effectively explain this analysis? If so, can you share any helpful tips? The most recent comment I've gotten back: "What this shows is which NMDS axis separates the communities, not the relationship between the edaphic factor and the
2007 Sep 05
1
ecological meaning of randomForest vegetation classification?
Hi, everyone, I haven't found anything similar in the forum, so here's my problem (I'm no expert in R nor statistics): I have a data set of 59.000 cases with 9 variables each (fractional coverage of 9 different plant types, such as deciduous broad-leaved temperate trees or evergreen tropical trees etc.), which was generated by a vegetation model. In order to evaluate the quality of
2012 Oct 04
4
Creating vegetation distance groups from one column
Hi R listers, I am trying to group distances of nests to the vegetation into classes that are define by (0-5m, 6-10m, 11-15m, 16-20m, 21-25m, 26-30m, 31-35m, 36-40m, 41-45m, 46-50m, 51-55m, 56-60m). Each row is a nest and all the distances to the vegetation is in a column. In plyr, I have tried - below script but I think I am going about this the wrong way and am not successful. #Veg index
2003 Dec 09
2
packages for ecologists
Hello R-user, sorry for this very off-topic question. But I shall present R to my dept. (pro's and con's and what it can do). The pro's and con's are easy but not what R can do (additional to the "normal" statistics). I looked through the packages, but the enormous amount of packages makes it very difficult for me to decide which one is worth mentioning. I used
2008 Nov 11
1
data type problem for vegan package
Dear all, I'm using R2.8 version, and am trying to do NMDS and calculate other diversity indices in vegan package. The problem is that it works with a small set of data (43 X 23; row by column), but the following error message comes up with a larger data set (43 X 104) (it seems not large to me at all). I made it sure that all data are of numeric type as required. >gh1.H=diversity(gh1)
2008 Nov 12
1
gam help (really a vegan question)
What does Generalized Cross Validation score mean. I preform and ordisurf on an ordination (nmds) with an environmental variable. I am trying to figure out "how well" the environmental varibles predict/explain the sites placements in species space. Any help would be greatly appreciated. Any pointers to literature... would be welcome. thanks in advance, -- Stephen Sefick Research
2012 Jul 13
0
How to simulate the relationship of vegetation and groundwater in Minqin Oasis, Gansu Province, China
*Dear **Madam**/**Sir,* *What would happen if we irrigate the degraded land using the desalinated saline water in Minqin Oasis, Gansu Province, China? Can we prevent the disappearing of Minqin Qasis?* * * *Background:* *1. **The Minqin Oasis is surrounded by two deserts, Badain Jaran Desert and Tengger Desert. * *2. **Water is the root of ecological
2008 May 23
0
how to compute "explained variance" in metaMDS(vegan)?
Dear all, I used metaMDS (vegan) to generate two NMDS axis and now I would like to know the amount of variance explained for each axis. Is there a way to do that? kind regards, miltinho [[alternative HTML version deleted]]
2011 Sep 23
0
vegan rda na adaptation
Dear R users, I know, the topic is more related to the r-sig-ecology. I decided to post it to the r-help as some specific topics of my question deals with NA-values and RDA (R vegan) and an adaptated RDA code due to a specific study design (including a second matrix). I am calculating a RDA for a dependent matrix (different variables for tree performance) and different explanatory