Indicator semivariograms are indeed the perfect tools for
detecting the presence of scale-dependent correlations
A good reference for application of geostat structural tools
to ecological data is:
Rossi RE, Mulla DJ, Journel AG, Franz EH (1992) Geostatistical
tools for modeling and interpreting ecological spatial dependence.
Ecol. Monogr. 62: 277-314
Regarding the general issue of scale-dependent correlations,
you can take a look at the following references:
- Goovaerts P, Webster R (1994) Scale-dependent correlation
between topsoil copper and cobalt concentrations in Scotland.
Eur. J. Soil Sci. 45: 79--95
- Goovaerts P (1997) Geostatistics for natural resources evaluation.
Oxford Univ. Press, New-York, 483 pp.
| \ / | Pierre Goovaerts
|_ \ / _| Assistant professor
__|________\/________|__ Dept of Civil & Environmental Engineering
| | The University of Michigan
| M I C H I G A N | EWRE Building, Room 117
|________________________| Ann Arbor, Michigan, 48109-2125, U.S.A
_| |_\ /_| |_
| |\ /| | E-mail: goovaert@...
|________| \/ |________| Phone: (734) 936-0141
Fax: (734) 763-2275
On Wed, 15 Apr 1998, Yoshiro Nagao wrote:
> We collected several insect species(A,B,C,D...) at sampling locations.
> Species A and B are negatively correlated in number at each the location.
> However, when I make a interpolated picture by inverse distance weighting,
> the density picture for A and B are nearly similar and are overlapped.
> ( I made the programme.)
> I concluded that species A and B are in competition in micro habitat,
> but their macro habitat are rather same.
> Actually A and B are near on their phylogenic tree.
> How can I geo-statistically show such a scale dependent
> spatial correlation?
> "Variogram" is the suitable method?
> It would be appreciated if a good book on this matter is
> "Steve Friedman" <friedman@...> sama said:
> >I'm working with a very large regional analysis of presettlement vegetation
> >patterns using General Land Office records. This data set is a point base
> >system. Each point consists of from 1 - 4 entries for a tree species present
> >at that location, absence data is not included in the data collection process.
> >I'd like to model the presence of each species using indicator variograms for
> >comparisons between the species and secondly to compare results from
> >spatial autocorrelation for nominal data.
> >My questions:
> >1. Where can I find software applications for indicator variograms?
> >2. What is the relationship between indicator variograms and nominal
> > spatial autocorrelation? My assumption is that the techniques should
> > produce similar results. Am I correct?
> Nagao Yoshiro
> International Centre for Medical Research
> Kobe University
> Nagao Yoshiro
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