This study investigated patterns of tree and fern species diversity and turnover along an elevational gradient in northern Ecuador. It found that (1) fern diversity decreased with increasing elevation while tree diversity followed a hump-shaped pattern, (2) turnover rates were higher for ferns than trees but became similar when analyzing ferns in the same elevational range as trees, and (3) elevation was the main factor structuring plant communities more so than geographic distance or soil conditions.

1. Species diversity and turnover of trees and ferns along
Northern Ecuador Andean foothills
Gabriel M. Moulatlet1, Byron Maza1,3, Marina Rodes Blanco1, Karolina Riaño2
1Universidad Regional Amazónica Ikiam-ECU; 2 Cátedra CONACyT, Universidad de Guadalajara-MEX, 3Universidad Yachay-ECU

2. 1) The eastern flank of the Andes of Ecuador
represents a major data gap on species diversity.
2) It is formed by a long altitudinal gradient where
mountains of diverse orogenetic stages are found
3) Ecological filtering may have promoted similar
diversity patterns of distinct taxa
4) Here, we investigate alpha and beta diversity
patterns of trees and ferns along an altitudinal
gradient

3. Pteridophytes 10 plots1 - 418 m to 3471 m
Trees 9 plots2 - 373 m to 1826 m
1 – Magnusson et al. 2005. Biota Neotropica; 2- Cueva et al. 2012. MAE Ecuador - Proyecto ENF; 3 – Anderson et al 2011. Ecology Letters
Napo province of Ecuador
Species sampling
1) Alpha diversity (species number) and Principal
Coordinate analysis (PCoA) to model
community structure patterns along
elevational gradient
2) Beta diversity to compare turnover rates
3) Mantel Tests to model pair-wise dissimilarities
as a function of elevation and
geographic distance
Analysis3
643
3447
3308
3465
3471
1558 611
2018
1767
418
-1
0
1
-0.5 0.0 0.5 1.0
PCoA 2
PCoA1
Ferns - Abundances
643
3447
3308
3465
3471
1558 611
2018
1767
418
-1.5
-1.0
-0.5
0.0
0.5
1.0
-0.5 0.0 0.5 1.0
PCoA 2
PCoA1
Ferns - Occurrence
373389
394
892
1007
1195
1421
15761826
-0.4
-0.2
0.0
0.2
0.4
-0.2 0.0 0.2
PCoA 2
PCoA1
Trees - Abundances
373
389 394
892
1007
1195
14211576
1826-0.2
0.0
0.2
0.4
-0.2 0.0 0.2
PCoA 2
PCoA1
Trees - Occurrence
373 - 3471
Elevation range (m)
Patterns of floristic similarity between plots. Numbers = Elevation
0.25 - 70
Distance between plots
(Km)

4. *Adj R.Squared = 0.74*Adj R.Squared = 0.74*Adj R.Squared = 0.74*Adj R.Squared = 0.74*Adj R.Squared = 0.74*Adj R.Squared = 0.74*Adj R.Squared = 0.74*Adj R.Squared = 0.74*Adj R.Squared = 0.74*Adj R.Squared = 0.745
10
20
30
35
500 1500 2500 3500
Elevation
Richness
Ferns
R.Squared = 0.44R.Squared = 0.44R.Squared = 0.44R.Squared = 0.44R.Squared = 0.44R.Squared = 0.44R.Squared = 0.44R.Squared = 0.44R.Squared = 0.44
60
70
80
90
100
500 1000 1500
Elevation
Richness
Trees
*Adj R.Squared = 0.78*Adj R.Squared = 0.78*Adj R.Squared = 0.78*Adj R.Squared = 0.78*Adj R.Squared = 0.78*Adj R.Squared = 0.78*Adj R.Squared = 0.78*Adj R.Squared = 0.78*Adj R.Squared = 0.78*Adj R.Squared = 0.78
-0.50
-0.25
0.00
0.25
500 1500 2500 3500
Elevation
PCoA1-PA
*Adj R.Squared = 0.62*Adj R.Squared = 0.62*Adj R.Squared = 0.62*Adj R.Squared = 0.62*Adj R.Squared = 0.62*Adj R.Squared = 0.62*Adj R.Squared = 0.62*Adj R.Squared = 0.62*Adj R.Squared = 0.62
-0.2
0.0
0.2
0.4
500 1000 1500
Elevation
PCoA1-PA
*Adj R.Squared = 0.81*Adj R.Squared = 0.81*Adj R.Squared = 0.81*Adj R.Squared = 0.81*Adj R.Squared = 0.81*Adj R.Squared = 0.81*Adj R.Squared = 0.81*Adj R.Squared = 0.81*Adj R.Squared = 0.81*Adj R.Squared = 0.81
-0.25
0.00
0.25
500 1500 2500 3500
Elevation
PCoA1-ABU
*Adj R.Squared = 0.82*Adj R.Squared = 0.82*Adj R.Squared = 0.82*Adj R.Squared = 0.82*Adj R.Squared = 0.82*Adj R.Squared = 0.82*Adj R.Squared = 0.82*Adj R.Squared = 0.82*Adj R.Squared = 0.82
-0.25
0.00
0.25
500 1000 1500
Elevation
PCoA1-ABU
0 500 1000 1500 2000 2500 3000
1.00.80.60.40.20.0
Distance
Similarity
Ferns: b = 0.06 , pseudo.r = 0.36
Trees: b = 0.1 , pseudo.r = 0.72
Ferns (subset): b = 0.15 , pseudo.r = 0.61
0.0
0.2
0.4
0.6
Ferns(subset)xDistance
Ferns(subset)xElevation
FernsxDistance
FernsxElevation
TreesxDistance
TreesxElevation
TreesxElevation-Distance
TreesxElevation-Soils
TreesxSoils
TreesxSoils-Distance
Correlation(r)
Alpha diversity (species number)
1) Pteridophyte alpha
diversity decrease
towards higher
elevations; Tree alpha
diversity is hump-
shaped
Turnover rates
2) Turnover rates (b) are
stronger for ferns than
trees. Fern data was
subset to tree plot
range showed similar
turnover rates.
Mantel test
3) Elevation is the main factor
structuring communities, more
than geographic distance or
even soil conditions.

5. 1) Higher fern alpha diversity in the low altitudes can be due higher
nutrient accumulation by intensive erosion process in the area.
2) Elevation is the main driver of both community structure, most likely
because it correlates with optimum moisture and temperature
conditions for most species.
3) Turnover rates are similar for a fern and trees at the same elevational
range. Both groups are exposed to similar environmental filtering that
shaped species communities.
4) Our preliminary results indicate that trees and fern communities may
be driven by similar environmental conditions. Further research will
help to disentangle the main drivers of alpha and beta patterns.
Discussion & Conclusions