Bi-annual Conference of International Society for Ecological Economics.
From 01st - 14th July 2004
To be held in Montreal
Canada. http://www.iseemontreal2004.com/teaser/teaser_new.html
Fractal patterns in species distributions of some British scarce plants
By
Georges Herbert, CHEKUIMO TAGNE
P. O. Box 8047 Yaounde
Cameroon
Tel.: +237 761 5579
+237 220 8205
Email: azpa01@ureach.com chekuimo@hotmail.com

Type of Presentation : the abstract is intended for a Poster.
Name of Invited Symposium : Bi-annual Conference of International Society for Ecological
Economics, from 01st - 14th July 2004, to be held in Montreal, Canada.
Authors and Addresses : Georges Herbert, CHEKUIMO TAGNE, P. O. Box 8047
Yaounde-Cameroon ( chekuimo@hotmail.com
)/ Kunin, W. E ., Faculty of Biological
Sciences, school of Biology, Centre for Biodiversity and Conservation, Leeds University-UK
( W.E.Kunin@leeds.ac.uk
)/ Pocock, M.
, Faculty of Biological Sciences, school of Biology,
Centre for Biodiversity and Conservation, Leeds University-UK
( m.j.o.pocock@leeds.ac.uk
)/ Aston, R.
The theme of the 2004 meeting : "Challenging Boundaries: Economics, Ecology and
Governance"
Topic Area : Conservation issues concerning plants
Title : Fractal patterns in species distributions of some British scarce plants
Abstract : The analysis, measurement, and management of species abundance is central to ecology and conservation biology, but it has proved difficult to find a single index that adequately reflects the commonness or rarity of species across a range of spatial scales. The spatial distribution and fractal structure of two British scarce plants, Lobelia urens (heath lobelia) and Phyteuma orbiculare (round-headed rampion), have been examined at several different scales. The two species have similar degrees of local patchiness at scale coarser than
50 km and have contrasting coarse-scale between 50 km and 1 km scales, but differed consistently in the slopes of their scale-occupancy curves distributions at scale finer than 1 km. The slope of the spatial log-log plot of L urens is not constant, but varies systematically with scale, and from habitat to habitat at the same spatial scale. Abundance estimates suggest that the species P. orbiculare is found to be clumped at all scales, whereas L. urens is dispersed at intermediate scale. Fractal dimension analysis suggests that this changes through scale. The distribution varied in their pattern from highly clumped to randomly dispersed.
Fairly predictions of L. urens can be made from 50 m and 200 m.
Fractal dimension, Conservation issues, conservation schemes

Abstract : The analysis, measurement, and management of species abundance is central to ecology and conservation biology, but it has proved difficult to find a single index that adequately reflects the commonness or rarity of species across a range of spatial scales. The spatial distribution and fractal structure of two British scarce plants, <i>Lobelia urens</i>
(heath lobelia) and <i>Phyteuma orbiculare</i> (round-headed rampion), have been examined at several different scales. The two species have similar degrees of local patchiness at scale coarser than 50 km and have contrasting coarse-scale between 50 km and 1 km scales, but differed consistently in the slopes of their scale-occupancy curves distributions at scale finer than 1 km. The slope of the systematically with spatial log-log plot of <i>L urens</i> is not constant, but varies scale, and from habitat to habitat at the same spatial scale.
Abundance estimates suggest that the species <i>P. orbiculare</i> is found to be clumped at all scales, whereas <i>L. urens</i> is dispersed at intermediate scale. Fractal dimension analysis suggests that this changes through scale. The distribution varied in their pattern from highly clumped to randomly dispersed. Fairly predictions of <i>L. urens</i> can be made from 50 m and 200 m.
<i>Fractal dimension, Conservation issues, conservation schemes</i>
Chair own and Name of Contact : CHEKUIMO TAGNE Georges Herbert, P. O. Box
8047 Yaounde-Cameroon (chekuimo@hotmail.com)
CHEKUIMO_Bi-annual Conference ofISEE 2

Table :
Fractal dimension ( D b
) of the two focal species
Species 200-100 km 100-50 km
From National data (since 1987)
50-20 km 20-10 km 10 to 5 km
Phyteuma
Lobelia
1
1
1
0.58
0.68
0
0.84
0
0.62
0.22
Species 1 to
0.5 km
0.5 to
0.2 km
0.2 to
0.1 km
Form field surveys (June - July 2002)
0.1 to
0.05 km
0.05 to
0.02 km
0.02 to
0.01 km
0.01 to
0.005 km
Phyteuma 0.58 1 1.22 1.19 1.46 1.34 1.38
5 to 2 km
0.48
0
0.005 to
0.002 km
1.49
0.58 0.55 1.13 1.44 1.25 1.49 1.47 1.08 Lobelia
Figures :
2 to 1 km
0.52
0.19
0.002 to
0.001 km
1.30
1.09
Lobelia urens and Phyteuma orbiculare
1000000
100000
10000
1000
100
10
Phyteuma
Lobelia
1
Log Scale (km)
Figure 1 : Resolution of map grid calculated from linear regressions of “log (cells occupied)” against “log(map scale)”.
CHEKUIMO_Bi-annual Conference ofISEE 3

Lobelia urens
100000
10000
1000
100
10
Lobelia
Predictions from 100m and 1 km
Predictions from 50 m and 200 m
1
Log Scale (km)
Figure 2 : L. urens
’ predictions from 100m and 1 km (purple), and from 50 m and 200 m
(dark blue).
Phyteuma orbiculare
1000000
100000
Phyteuma orbiculare
Predictions from 100m and 1 km
Predictions from 50 m and 200 m
10000
1000
100
10
1
Log Scale (km)
Figure 3 :
P. orbiculare’s
predictions from 100m and 1 km (bright green), and from 50 m &
200 m (red)
CHEKUIMO_Bi-annual Conference ofISEE 4