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African Journal of Environmental Economics and Management ISSN 2375-0707 Vol. 10 (1), pp. 001-011, 
January, 2022. Available online at www.internationalscholarsjournals.org © International Scholars Journals 

 

Author(s) retain the copyright of this article. 
 

 

Full Length Research Paper 

 

When ecological functions are more important than 
richness: A conservation approach 

 
Vagner Santiago do Vale*, Ivan Schiavini, Ana Paula de Oliveira and André Eduardo Gusson 

 
Laboratory of Plant Ecology, Federal University of Uberlandia (Campus Umuarama), CEP: 38 400-902, 

Uberlândia - MG, Brazil. 
 

Accepted 7 October, 2021 
 

In this work, we utilize the assessment of functional groups (FG) and functional diversity (FD) to 
evaluate and compare the ecological functions of two types of dry forest of South Eastern Brazil. 
Hence, we hypothesized that forests with different species richness could have similar FD and FG, but 
distinct ecological functions. The floristic composition from two physiognomies (deciduous and 
semideciduous forests) of six tree communities was carried out in the state of Minas Gerais, South-
Eastern Brazil. The inventory was pooled together considering the traits of species such as: shade 
tolerance, deciduousness and desiccation tolerance of seeds; one structural feature: position on 
vertical strata; and two animal-plant interactions: dispersal syndrome and pollination syndrome. We 
chose two multivariate analyses to infer to the functional groups and used the one-way ANOVA to test 
differences between the abundance of the groups in the two physiognomies. The difference in FD 
between the two physiognomies was tested using the Shannon diversity index and the Hutcheson t-
test. Both physiognomies had the same FG and FD. The most abundant group in the semi-deciduous 
forest was G1, which occupied lower communities (shade tolerant and perennial), whereas G4 for 
deciduous forest was anemochoric and autochoric of superior community strata that is light 
demanding. The functional diversity between the two physiognomies showed that semi-deciduous 
contains more species than the deciduous ones (75% more species) and are more diverse with the 
Shannon index of 3.3. Hence, the number of species alone had little importance when we analysed 
functions in ecosystems. The more abundant groups in each forest had completely different traits and 
were complementary in their functions to the ecosystem. In this case, a species-rich and less- species-
rich system provided different key functions to the ecosystem despite their differences in species 
richness, diversity or physiognomic type. The use of species-rich and less- species- rich areas would 
present different key groups, and as such, this may be the best alternative to choose priority areas for 
conservation. 

 
Key words: Complementarity, deciduous forest, dry forest, functional diversity, functional groups, semi-

deciduous forest. 

 
INTRODUCTION 

 
The classification of functional groups (FGs) reduces a 
large number of species in a small group of functional 
types, which incorporate the same responses to 
perturbations or are similar with regard to dispersion, 
competition and survival processes (Hubbell, 2005; Skov, 
2000). Groups of species may also reveal features of  
 
 
 
*Corresponding author. E-mail: vsvale@hotmail.com. 

 
 
 
 
system functionality (Swaine and Whitmore, 1988) which 
would be difficult to detect when looking at the species 
separately.  

The use of FGs is particularly important because the 
diversity of functional types is more important than the 
diversity of species for many aspects of ecosystem 
performance (Pendry et al., 2007) . For example, plant 
reproductive success tends to increase with the functional 
diversity of pollinators (Fontaine et al., 2006). 
Additionally, functional diversity increase plant 



2 

 

 
 
 

 

productivity and light penetration in a grassland-savanna, 
but species diversity does not (Tilman et al., 1997). Thus, 
functional diversity (FD) can be defined as a variety of 
life-history traits presented by an assemblage of 
organisms (Fontaine et al., 2006; Mayfield et al., 2005) 
and it is critical for the maintenance of ecosystem 
processes and properties (Tilman et al., 1997).  

The usual measure of FD is the number of functional 
groups in a community (Hooper and Vitousek, 1997; 
Tilman et al., 1997) and the number of species and traits 
that influence the functional groups (Petchey and Gaston, 
2002b, 2006). A greater number of traits and species are 
associated with more functional groups and, therefore, 
more FD (Petchey, 2004; Petchey and Gaston, 2002a), 
although this is not always true. However, a greater 
number of species does not necessarily mean more traits 
(Petchey and Gaston, 2002a) or more FD and FG. 
Hence, we hypothesize that forests with differences in 
species richness could have similar FD and FG, but 
distinct ecological functions in the ecosystem.  

For a good representation of ecological functions, we 
need to choose traits that represent important functions to 
systems. Most studies on functional diversity in plant 
communities have focused on the importance of traits 
associated with plant physiology, like sunlight interception 
or shadow tolerance (Girao et al., 2007). Little is still 
known with regards to the functional diversity of traits that 
affect ecosystem functioning, such as those related to 
plant- animal interactions (Fontaine et al., 2006; Mayfield 
et al., 2005), mainly on the tropical ecosystems with high 
diversity and complex interactions. Therefore, studies 
which associate plant physiology and plant-animal 
interactions are needed to better understand and 
compare forest systems.  

To test the hypothesis we used a Brazilian seasonally 
dry tropical forest, one of the most threatened 
ecosystems in Brazil (Espirito-Santo et al., 2009). Also, 
dry forests are neglected by research and conservation 
efforts compared to the tropical rain forests (Sanchez-
Azofeifa et al., 2005), maybe because they lower the 
diversity of plant species on the seasonal forests. Dry 
forests can be subdivided into seasonal deciduous and 
semi-deciduous forests (Oliveira-Filho and Ratter, 2002). 
Both are physiognomically identical in terms of structural 
parameters (height of canopy, density and basal area) 
and appear next to each other or are connected in the 
landscape, but the first one is less rich in species. 
However, we know little about the ecological functions in 
the ecosystem of these threatened forests, and as such, 
comparisons of ecological functions in similar 
physiognomic environments are still lacking. We aimed to 
answer the following questions to test our hypothesis: (1) 
Can less-species-rich forests have similar functional 
diversities as compared to species-rich forests? (2) Are 
the functional groups of these forests similar? (3) Do 
similar functional groups have the same value of the 
ecosystem? (4) Can the functional diversity in 

  
 
 
 

 

complementary forests justify different conservation efforts? 

 
METHODS 
 
The study was conducted in six fragments of seasonal forests in the 
state of Minas Gerais, South-eastern Brazil at coordinates 18°56’ S 
and 48°12’ W, 18°40’ S and 48°24’ W, 18°29' S and 48°22' W for 
semideciduous sites and 18°48’ S and 48°07’ W, 18°47’ S and 
48°06’ W, 18°39’S and 48°25’ W for deciduous sites. The sites were 
in the same climatic zone, characterized by warm temperatures 
throughout the year with a rainy summer and a dry winter. The 
regional climate is Aw (tropical savannic) according to the Köppen 
classification (1948), with a mean annual precipitation of 228.5 mm 
in each wet month (October to march) and 35.5 mm in each dry 
month (April to September), and a mean annual temperature of 
23.7°C available in a weather station called the 5° Meteorological 
District/Uberlândia Station, Brazil. A plant species list for three 
seasonal deciduous and three semi-deciduous sites was collected in 
arboreal community studies (Kilca et al., 2009; Siqueira et al., 2009; 
Vale et al., 2009). An area of one hectare was sampled at each site 
and all trees, with a circumference at breast height (CBH to 1.3 m 
above ground floor), that are equal to or larger than 15 cm were 
measured. Only species with at least five individuals in each site 
were analysed. The data of the three deciduous sites were united as 
one sample and the same was done with the data for the three 
semi-deciduous sites. 

For each species, data were collected for three physiological 
traits: (1) shade tolerance, (2) deciduousness and (3) desiccation 
tolerance of seeds; one structural feature: (4) position on vertical 
strata; and two animal-plant interactions: (5) dispersal syndrome 
and (6) pollination syndrome. These characteristics are illustrated in 
Table 1. Information about these ecological attributes were 
researched in scientific articles and specialist books, field 
observations, specialist conferences and the analyses previously 
performed on the structure of tree communities (Table 1) . A total of 
53 species in the deciduous forest and 93 species in the semi-
deciduous forest were analysed. The complete list of species, with 
the occurrence, density, matrix of treats and group is shown in 
Appendix 1. The same species found in both forests were 
considered once in the matrix. Therefore, a matrix with 132 species 
and 19 traits (Table 1 and Appendix 1) was used for analysis. We 
converted the data into a presence/absence matrix with species 
and their ecological attributes. The columns were exclusive for each 
characteristic. Following this, a matrix of ecological distance was 
produced (Petchey and Gaston, 2002b). The functional groups 
were derived by the distance matrix, using the “cluster” and the 
“correspondence” analyses. 

 
Cluster analysis 
 
The groups were defined by euclidian distance and a dendrogram 
generated through the group average (UPGMA). Multivariate 
clustering methods were used to see which groups of plant species 
would emerge. These methods calculated the similarity or 
association measures based on the extent to which species have 
attributes in common (Leishman and Westoby, 1992). The 
cophenetic correlation for the generated dendrogram was 
calculated. The coefficient of cophenetic correlation (equivalent to 
the Pearson coefficient) was proposed as a measure of how a 
dendrogram maintains the original pair wise distances (Bussab and 
Morettin, 1990). The statistical analyses were performed using the 
FITOPAC SHELL 1.6.4 program (Shepherd, 2004). 

 
Correspondence analysis (CA) 
 
This exploratory technique could represent the correspondence 



3 

 

 
 
 

 
Table 1. Characteristics and their respective ecological functions used for the distance ecological matrix.  

 
Trait Classification  Categories  Ecological function 

Dispersion syndrome Diaspores dispersed by wind  Anemochory  Long dispersion, which is affected slightly by fragmentation. 

 Free fall or ballistic mechanisms  Autochorory  Short distance dispersion, highly affected by fragmentation. 
 Birds  Ornitochory  Medium distance of dispersion, affected by fragmentation and 
     a resource for birds. 
 Mammals  Mammaliochory  Short distance dispersion, highly affected by fragmentation 
     and a resource for mammals. 

Deciduousness Species were all leaves     
 Fall off during some period of the dry station  Deciduous  High litter release and canopy opened to other plants. 
 Remain during the entire year  Perennials  Shade and refuge for animals, increases shading to other 
     plants. 

Shadow tolerance Light environment required for establishment     
 Tolerate shade under other trees  Shade tolerant  Low growing species and climax species, related to maturity 
     of forest. 
 Need direct sunlight to develop  Light demanding  Fast growing species, generally represent initial stages of 
     regeneration. 

Vertical strata Based on the stature commonly reached by adult     
 individuals     

 Always reaches the canopy  Typical canopy  Represents greater biomass accumulation and shades 
     smaller species. 
 Sometimes, it reaches the canopy  Intermediate strata  Integrate canopy and understory, generally representing 
     some strata. 
 Usually do not reach the upper layers of the  Typical understory  Low basal area but high density species, is a distinct habitat 
 forest    for animals than canopy. 

Seed desiccation Related to how seeds remain in the environment     
tolerance until the next season     

 Seeds are able to survive until the next season  Orthodox  Form seed banks in forest. 
 Seeds are unable to survive until the next  Non-orthodox  Form a "bank of seedlings" but not a seed bank 
 season     



4 

 

     Vale et al. 273 

Table 1. Contd.       
       

Pollination syndrome Species were classified by animal pollinator      
 Body size under 5 mm  Very small insects  Prevent inbreeding, promotes genetic variability and a  
     resource to very small insects.  

 Small bees, wasps and flies (body size 5-12 mm)  Small insects  Prevent inbreeding, promotes genetic variability and a  
     resource to bees, wasps and flies.  

 Bees with large size body (more than 12 mm)  Large bees  Prevent inbreeding, promotes genetic variability and a  

     resource to big, solitary bees.  

 Beetles  Beetles  Prevent inbreeding, promotes genetic variability and a  
     resource to beetles.  

 Butterflies and moths  Lepidoptera  Prevent inbreeding, promotes genetic variability and a  
     resource to moths and butterflies.  

 Bats  Bats  Prevent inbreeding, promotes genetic variability and a  
     resource to bats.  

 

 
between species. We considered this technique 
appropriate for detecting functional groups because the 
ecological distance between the species is expressed 
graphically. This analysis was performed using FITOPAC 
SHELL 1.6.4 program (Shepherd, 2004).  

To compare the functional diversity, we calculated 
Shannon diversity index (Brower et al., 1997) for the 
functional groups that is resultant from the cluster and 
correspondence analysis. Unlike the traditional Shannon 
index, the abundance of species is replaced by abundance 
of groups. Therefore we treat the Shannon index value for 
functional groups like functional diversity. Then we 
calculated and compared the significance of these indices 
with Hutcheson t-test for the deciduous and semi-
deciduous forests (Brower et al., 1997).  

One-way ANOVA was used to test differences in the 
abundance of groups between deciduous and semi-
deciduous forests, and to test differences in group species 
number per plot. For these tests, we randomly selected 50 
plots in the deciduous and semi-deciduous forests. The 
Bonferroni post-hoc procedure was applied to assess 
differences in group abundance among the sites. 
Abundance data were transformed into a logarithmic scale 
(base 10) for data standardization.  

The intention of these analyses was to determine if the 
areas with lower species richness and diversity have 
priority for conservation and if these criteria are valid for dry 
forests. We think that these methods, using FD and 

 

 
FG, could help in prioritizing conservation by focusing on 

ecosystem functionality. 
 
 

RESULTS 

 

The 53 tree species analysed here represented 
92% of the individuals found in the deciduous 
sites. The 93 tree species analysed in semi-
deciduous sites represented 91% of the total of 
individuals in this physiognomy. These high 
values indicate the high representation of species 
analysed in these systems.  

Appendix I shows the list of species used for the 
analysis of functional groups with the number of 
individuals and the respective attributes of each 
one.  

The dendrogram formed five groups (Figure 1) 
with a high cophenetic correlation of 0.77, thus the 
dendrogram and species ecological differentiation 
showed a good correlation. Therefore the number 
of functional groups is the same for both forests 
(five). The Hutcheson t-test for the Shannon index 
value found between forests for the five groups 

 

 

was not significant (p > 0.1; df > 500). This means 
that these forests have the same functional 
diversity. However, in the correspondence 
analysis of ecological distances, we could only 
view four cohesive groups. This was because two 
of the groups formed in the dendrogram (G3a and 
G3b) were joined together in the CA (Figure 2). All 
four groups contained deciduous and semi-
deciduous species. Therefore, the FG found in 
both analyses was strictly the same. The 
Hutcheson t-test for the Shannon index value 
found between the four groups in CA was not 
significant (p > 0.1; df > 500). This means that 
these forests have the same functional diversity 
for CA groups too, just like cluster analyses.  

After it was found that there were no great 
differences between both multivariate techniques, 
we concluded that both techniques were 
satisfactory for showing FG in forests. As there 
were no major ecological differences between 
groups G3a and G3b in the cluster analysis, 
hence we chose to use the results of the CA for 
the remainder of the analysis. Table 2 shows the 
ecological characteristics of the four groups found 



5 

 

  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Figure 1. Functional groups based on 
ecological distance formed by clustering in 
six seasonal dry tropical forests in South-
eastern Brazil. A cluster was defined by the 
Euclidian distance and UPGMA method. 
Group characteristics are shown in Table 2. 

 

 

in the semi-deciduous and deciduous forests. 
The abundance (number of individuals in each group) 

of the four groups varied between the forests. G1 was the 
most abundant group in semi-deciduous forests, while G4 
was the most abundant in deciduous forests (Figure 3a), 
but both groups had the same abundance according to 
the Bonferroni test (p > 0.05; df = 7). The five other 
groups showed no significant differences for abundance. 
The Bonferroni test showed that G1D, G3D, G3S, G2D 
and G4S had the same weight to ecosystem in terms of 
the number of individuals (p > 0.05; df = 7) (D is for 
deciduous and S is for semi-deciduous forest). One group 
(G2S - species on lower layers of the community is shade 
tolerant, deciduous, ornitochoric and pollinated by small 
insects and lepidoptera) was underrepresented in the 
semi-deciduous forest. These results reflect the 
environmental differences between both forests. As such, 
deciduous forests have more water deficit in soil during 
the dry season (Oliveira-Filho and Ratter, 2002), which 
influences the deciduousness in these sites. However, 
this feature of water stress in soil clearly separated the 
two physiognomies, not only due to the deciduousness 
which interferes with floristic and structural variations, but 

 
 
 
 

 

also in the main functions of these forests (compares G1 
and G4 in Table 2).  

Unlike the abundance, the number of species per group 
showed different results. The two most species-rich 
groups were the same as the most abundant groups for 
the forests (G1S and G4D - Figure 3b). However, the 
other groups were significantly different according to the 
Bonferroni test. Group G4S had more species than the 
remaining five groups and G3S had more species than 
the other remaining four groups (p < 0.01; df = 7). 
Therefore, these four groups (G1S, G4D, G4S and G3S) 
were more redundant in the ecosystem than the others 
were. As such, the remaining groups had the same 
number of species (p > 0.05; df = 7). These results show 
that the number of species do not always have a relation 
with the abundance of the groups formed. G3 has the 
same abundance for both deciduous and semi-deciduous 
forests (Figure 3a), but is much richer in the species on 
semi-deciduous forest (Figure 3b). The inverse occur in 
G2, with same richness (Figure 3b), but more abundant 
on deciduous sites (Figure 3a).  

When analysing the similar groups for both forests, we 
could see differences for groups per physiognomy. For 
example, G1 had more species and individuals in the 
semi-deciduous forest than in the deciduous forest 
(Figures 3a and 3b), and G4 was more abundant in the 
deciduous forest (p < 0.01; df = 7), but the number of 
species in both physiognomies was the same (p > 0.05; 
df = 7). Group G3 had the same number of individuals (p 
> 0.05; df = 7) in both forests, but the species number 
was much greater in the semi-deciduous forest (p < 0.01; 
df = 7) . Finally, G2 was more abundant in the deciduous 
forest (p < 0.01; df = 7), but the species number was the 
same in both physiognomies (p > 0.1; df  
= 7). This means that functional groups may have a 
greater influence on the floristic composition or structure 
in forests, depending on soil moisture. In the deciduous 
forest (drier) there was a greater variation in forest 
structure than in the number of species (greater 
abundance of G2 and G4 - Figure 3a, but no variation in 
the number of species in these groups - Figure 3b). 
Furthermore, the semi-deciduous forest was more rich in 
species (G3 - Figure 3b), but there was no variation in the 
abundance of this group (G3 - Figure 3a). 
 

 

DISCUSSION 

 

Can less-species-rich forests have similar functional 

diversities to species-rich forests? 
 
Seasonal dry tropical forests (deciduous and semi-
deciduous) are present in all tropical regions, but mainly 
in the neotropics (Miles et al., 2006). Deciduous forests 
are more associated with a water deficit in the dry season 
and are less rich in species (Oliveira-Filho and Ratter, 
2002; Ratter, 1992). However, the functional diversity, or 



6 

 

   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
  

-0.3 
   

0   0.05   0.1 0.15   0.2  0.25   0.3  0.35   0.4  0.45   0.5 
 

-0.45   -0.4  -0.35   -0.25   -0.2  -0.15   -0.1  -0.05  
 

         

         

          
Eixo 1 (65.21%) 

 
Figure 2. Functional groups based on ecological distance formed by correspondence analysis in six seasonal dry tropical forests in 
south-eastern Brazil. The black circles represent semi-deciduous species, the empty circles represent deciduous species and the 
grey circles represent species common to both physiognomies. The black solid lines show Group 1, the grey solid lines denote 
Group 2, the grey dotted lines denote Group 3 and the black dotted lines show Group 4. However, group characteristics are shown 
in Table 2. 
 
 

 
Table 2. Functional groups formed by correspondence and cluster analysis and their respective characteristics for six 

seasonal dry forests in Minas Gerais, Brazil.  
 

Functional 
Main determinant characteristics of the functional groups  

groups  

 
   

Group 1 (G1) Occupies lower layers of the community and is shade tolerant and perennial. Provides fruit 
 resources to birds. The pollination is performed by small insects, lepidoptera and very small 
 insects. There are non-orthodox seeds. 

Group 2 (G2) Occupies lower layers of the community and is shade tolerant. Unlike G1, it is deciduous. This 
 group provides fruit resources to birds. The pollination is performed by small insects and 
 lepidoptera. There is no distinction in tolerance of desiccation of seeds. 

Group 3 (G3) This is a zoochoric group from higher layers providing resources to mammals and birds. This 
 group is perennial and has shade-tolerant and light-demanding species. The greatest 
 diversification of pollinators occurs in this group (small insects, very small insects, moths, 
 butterflies and beetles). Most species are non-orthodox. 

Group 4 (G4) This is the only group that is abiotically dispersed (anemochoric and autochoric) and is fully 
 deciduous. It occupies the superior community strata and is light demanding. This is the only 
 group pollinated by large bees, but is still pollinated by small insects and lepidoptera. Most 
 species in this group are orthodox. 



7 

 

  
 
 
 

 
2.0 

 
 
 

1.5 
 
 

 
1.0 

 
 

 
0.5 

 
 

 
0.0 

 
 
 

 
Figure 3. One-way analysis of variance for the log number of individuals “A” and number of species “B” per group (G1, G2, G3 
and G4) for deciduous (D) and semi-deciduous (S) seasonal dry tropical forests with the Bonferroni post-hoc test. The same 

letters denote that there is no statistical difference and the different letters represent significant differences. The black points 
represent the means and the lines represent standard deviations. 

 
 

 

the extent of functional differences among the species in 
a community (Tilman et al., 2001), could be the same in 
deciduous forests as in semi-deciduous ones, despite 
their difference in species richness. Our results 
exemplified this. Semi-deciduous forests contain more 
species than the deciduous ones (75% more species) 
and are more diverse (the Shannon index for semi-
deciduous forests is above 3.3 and less than 2.8 in 
deciduous forests) (Kilca et al., 2009; Siqueira et al., 
2009; Vale et al., 2009), but both have the same FD 
(four) as shown by the study’s results. Hence, the number 
of species alone has little importance when analysing 
functions in ecosystems. Other studies demonstrated FD 
having a greater impact on ecosystem processes than 
species diversity (Tilman et al., 1997) and addressing 
questions about ecosystem processes (Chapin et al., 
2000; Diaz et al., 2001; Tilman et al., 2001). In some 
systems, a decrease in species richness can even lead to 
an increase in functional richness/diversity, increasing the 
number of ecosystem processes (Loreau et al., 2001; 
Micheli and Halpern, 2005). Thereby, less-species-rich 
systems could present similar FD to species-rich systems 
and both are important to ecosystem maintenance. Here, 
deciduous forest (a less rich system) has the same FD 
than semi-deciduous forest (a richer system). Thus we 
cannot neglect systems with lower species richness 
because, for some ecological attributes, they present the 
same number of functions systems with greater species 
richness. Many conservations efforts focus more on 
species-rich systems. However, we have demonstrated 
that systems with lower species richness could posses 
the same 

 
 
 

 

number of functions as species-rich systems, therefore 

having the same ecological importance. 
 
 

Are the functional groups of these forests similar? 

 

The functional groups in both forests were exactly the 
same in the attributes that were analysed. This was 
because the species in the deciduous forest had the 
same ecological functions than semi-deciduous species, 
even though there were fewer species. However, the 
number of species per group and number of individuals 
per group greatly varied. This could be observed in G1 
and even more clearly in G3. G1 was more abundant and 
much richer in species in the semi-deciduous forest, while 
G3 was equally abundant in both forests but was much 
richer in species in the semi-deciduous forest. This 
variation in species richness between these forests could 
be important when considering the ecological redundancy 
of the species in a group. This is particularly important 
because a greater number of species with similar 
characteristics represents a greater ecological 
redundancy (Walker et al., 1999). The higher the 
redundancy, the lower the chance of one species’ loss, 
resulting in the loss of a function to the ecosystem 
(Micheli and Halpern, 2005). Many species in a group 
represents more species capable of occupying the niche 
of a species affected by a perturbation (Loreau, 2000; 
Walker, 1992). If a rare species becomes extinct, this can 
be compensated by the growth of a similar dominant 
species (Smith and Knapp, 2003). In the case of a low 
redundancy, the loss of a species with a determinate 



8 

 

 
 
 

 

functional trait could have a great impact on the 
community, and the reverse is also true (Micheli and 
Halpern, 2005). In deciduous forests, some 
characteristics are more dangerous because fewer 
species do these functions (like G3). The study areas are 
in a threatened seasonal biome, in the Brazilian 
Savannas (Cerrado) (Myers et al., 2000). During the dry 
season in the savannas, the forests could be an 
important refuge for animals, particularly vertebrate 
dispersers. A greater number of plant species represents 
a greater capacity for maintaining vertebrate species 
(mainly for birds and mammals in this case) in the case of 
a disturbance. Species with ecological redundancy could 
not have the same tolerance to disturbance (Micheli and 
Halpern, 2005; Walker et al., 1999), and in deciduous 
forests, few species are available as resources for 
vertebrates. Here, climate changes may affect the high 
abundance of species which cannot be replaced by 
others with the same function. This could cause serious 
problems in supplying food to the animals in these forests 
and therefore alter the environmental relationships and 
functions. 
 

 

Do similar functional groups have the same value in 

the ecosystem? 
 
Despite the four groups being found in both 
physiognomies, the abundance of the groups or the value 
of each group in the ecosystem was clearly different. 
When the abundance of G1 and G4 are compared, it can 
be suggested that the major groups were different in both 
forests. Whilst these forests had the same FD, they had 
different weights for each group in the ecosystem and 
therefore distinct functions in the environment. This is 
very important because these two physiognomies are 
considered as the same “dry forest” in the literature. 
However, we demonstrated that these forests are 
complementary because they have different functions for 
the ecosystem. Semi-deciduous forests (dominated by 
G1) have more vertebrate resources. Birds and mammals 
have the preference to occupy different layers of the 
forest (Clark et al., 2001; Pearson, 1971). This preference 
could be linked to temperature, leaf density, luminosity 
and abundance of resources (Pearson, 1971; Richards, 
1996; Walther, 2002; Walther et al., 1999). More 
perennials of lower strata groups like G1 could provide a 
different luminosity and temperature for vertebrates than 
the canopy. In this case, the vertebrates that forage in the 
canopy should be distinct than those that forage in the 
understory. Group G3, for example, had the same 
abundance in deciduous and semi-deciduous species, 
but it is a canopy group and should have the same 
function in both forests. Therefore the importance of G1 
for the diversity of large animals, particularly those that 
forage in the understory, is a clear function to the 
ecosystem. This group also produces non-orthodox 

  
  

 
 

 

seeds. Non- orthodox seeds are linked to fresh fruit 
(Tweddle et al., 2003); therefore, G1 can provide 
constant shade and protection against insolation and also 
provide fresh fruit to animals in lower layers of vegetation. 
Pollinators do not respond clearly in groups because they 
do not form specific groups. 

Nevertheless, we highlighted the presence of very 
small insects that are only found in the understory 
species of G1. These pollinators contrast with the large 
bees found only in the canopy species (G4), 
demonstrating niche differentiation for pollinators in these 
forests. 

On the other hand, the deciduous forest (dominated by 
G4) could be considered as less affected by 
fragmentation processes because it is abiotically 
dispersed. The dispersion efficiency in superior strata is 
generally greater in anemochoric than zoocoric species 
(Clark et al., 2001) and species with a high dispersal 
capacity are less susceptible to fragmentation processes 
(Fahrig and Merriam, 1994; Frankie et al., 1974; Lord and 
Norton, 1990). Light demanding species, such as those in 
G4, can easily attain higher layers of communities having 
distinct colonization processes compared to G1. The 
occurrence of a group with tall heights dominating the 
deciduous forest is due to the diaspore dispersal distance 
increasing with plant height in wind dispersal (Deng et al., 
2008; Howe and Smallwood, 1982; Wikander, 1984; 
Yamamoto et al., 2007), and deciduousness is related to 
this syndrome because leaves could hinder the 
dispersion. The orthodox seed of this group also provides 
the chance to form a seed bank for future seasons.  

Deciduous forests could not even lose leaves, but twigs 
too (dry branches that fall from trees). Species which 
spend their lifetime under a closed canopy have more 
chances of being hit by debris (Deng et al., 2008). This 
could be a factor that favours the abundance of a higher 
group in a deciduous forest (G4) over the understory 
groups. The chance of a deciduous canopy recruit (G4 
species) being hit by debris is small because deciduous 
species generally grow faster than perennials 
(Cornelissen et al., 1996) and live in fewer understory 
areas.  

Also, light demanding species grow faster than shadow 
tolerant (Poorter and Bongers, 2006) species and the G4 
abundance indicated that deciduous forests can 
accumulate more biomass and recover faster after 
perturbation events. On the other hand, the lower 
abundance of G4 species provided by the perennial 
canopy in the semi-deciduous forest could facilitate the 
presence of shadow- tolerant plants in the lower layers of 
a community. Shade tolerant species are more persistent 
in the environment because they have more protection 
against herbivores, less mechanical disturbance due to 
the greater wood density (Chave et al., 2006; Coley, 
1983; Poorter et al., 2006; Swenson and Enquist, 2007) 
and they can provide a more stable understory in the 
semi-deciduous forest. 



9 

 

   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Figure 4. Fluxogram showing the steps in this work. Note that both forests, one with high species diversity and one 

with lower species diversity, are important to conservation. When two types of forest occur in the same 

environment, both need to be conserved to prevent the loss of ecological functions. 
 
 

 

Can the functional diversity in both complementary 

forests justify different conservation efforts? 
 
We argue that the so- called "dry forests" have different 
ecosystem functions. These forests are commonly 
classified according to the degree of deciduousness 
(Veloso et al., 1991; Scariot and Sevilha, 2005; Oliveira-
Filho and Ratter, 2002). However, we think that semi-
deciduous and deciduous forests have distinct traits and 
therefore distinct functions to the environment. Greater 
differences between species trait values represent 
greater trait complementarity independent of the number 
of species (Petchey and Gaston, 2002b). Species 
complementarity is related to species that occupy distinct 
spatial niches and thereby fulfil complementary functional 
roles (Loreau, 2000).  

In the present study, the species rich and not too 
species rich “dry forest” had key functional groups with 
distinct traits. Here, deciduous forests have mainly group 
G4 and semi-deciduous have mainly group G1. These 
groups are different too, in terms of their functions to the 
ecosystem and the forest. The first one is a canopy light 
demanding deciduous abiotically dispersed group (G4) 

 
 
 

 

and the other is an understory shade-tolerant perenial 
animal dispersed group (G1) (Figure 4).  

Furthermore, these forests are complementary in terms 
of functions. It is shown that the functions performed by 
one type of forest were not performed as often in the 
other type, hence the more abundant groups in these 
forests (G1 and G4) are distinct in several key features of 
a forest or even in an ecosystem. From a wider view of 
both types of forest co-occurring in the cerrado biome, 
the deciduous forest is considered as less species rich 
and the semi-deciduous forest is considered as species 
rich (Oliveira-Filho and Ratter, 2002). We think that the 
co-occurrence of a species rich and less species rich 
system could provide different key functions to an 
ecosystem and that both can be very complementary 
despite differences in species richness, diversity or 
physiognomic type. At least, this seems to be true for the 
dry forest. The functional group diversity is an important 
determinant of ecosystem functioning for some locations, 
but not for others (Petchey, 2004), and functional groups 
do not represent the same value to an ecosystem due to 
the differences in abundance of groups. For the dry 
forest, the most important factor is the abundance of key 



10 

 

 
 
 

 

functional groups and thus their complementarity for the 
ecosystem (Figure 4). Some papers have shown the 
importance of complementarity (Loreau, 2000; Petchey 
and Gaston, 2002b) and we think this should be analysed 
in more detail to show its real importance to a system. In 
this work, deciduous and semi-deciduous forest is shown 
to be complementary (G1 and G4 differences in Table 2), 
so both forests are important for ecosystem in different 
ways despite their species richness. Henceforth, we 
should think in terms of a system rather than the kind of 
forest, number of species or species diversity alone, but 
we should also think in terms of the functions that a 
determinate area could provide for all “microsystems” 
existing there. On a broader scale, we can argue that 
less-species -rich systems, when co- occurring with 
systems of greater species richness, could provide 
different services to ecosystems and we need to pay 
more attention to this fact when determining 
conservations areas (Figure 4). The use of species rich 
and less-species-rich areas would present different key 
groups or high complementarity and may be the best 
alternative we have for choosing priority areas for 
conservation. 
 

 

ACKNOWLEDGMENTS 

 

The authors acknowledge the Fundação de Amparo à 
Pesquisa do Estado de Minas Gerais (FAPEMIG CRA 
0694/08) for financial support and the CAPES Agency for 
fellowship to Vagner S. do Vale. Also, they express their 
gratitude to two anonymous reviewers for their thoughtful 
and detailed comments on the manuscript. 
 

 
REFERENCES 
 
Brower JE, Zar JH,von Ende CN (1997). Field and laboratory methods 

for general ecology. The McGraw-Hill Companies, Massachusetts.  
Bussab WO, Morettin PA (1990). Estatística Básica, São Paulo.  
Chapin FS, Zavaleta ES, Eviner VT, Naylor, RL. Vitousek, PM, 

Heynolds HL, Hooper DU, Lavorel S, Sala OE, Hobbie SE, Mack MC, 
Diaz S (2000). Consequences of changing biodiversity. Nature, 405: 
234–242.  

Chave J, Muller-Landau HC, Baker TR, Easdale TA, Steege HT, Weeb 
CO (2006). Regional and phylogenetic variation of wood density 
across 2456 neotropical tree species. Ecol. Appl., 16: 2356–2367. 

Clark CJ, Poulsen JR, Parker VT (2001). The role of arboreal seed 
dispersal groups on the seed rain of a lowland tropical forest. 
Biotropica, 33: 606–620. 

Coley PD (1983). Herbivory and defensive characteristics of tree 
species in a lowland tropical forest. Ecol. Monogr. 53: 209–233. 

Cornelissen JHC, Diez PC, Hunt R (1996). Seedling growth, allocation 
and leaf attributes in a wide range of woody plant species and types. 
J. Ecol., 84: 755–765. 

Deng F, Zang R, Chen B (2008). Identification of functional groups in an 
old-growth tropical montane rain forest on Hainan Island, China. For. 
Ecol. Manage., 255: 1820–1830. 

Diaz S, Noy-Meir I, Cabido M (2001). Can grazing response of 
herbaceous plants be predicted from simple vegetative traits? J. Appl. 
Ecol., 38: 497–508. 

Espirito-Santo MM, Sevilha AC, Anaya FC (2009). Sustainability of 

tropical dry forests: Two case studies in southeastern and central 

  
  

 
 

 
Brazil. For. Ecol. Manage., 258: 922–930.  
Fahrig L, Merriam G (1994). Conservation of fragmented populations. 

Conserv. Biol., 8: 50–59. 
Fontaine C, Dajoz I, Meriguet J (2006). Functional diversity of plant-

pollinator interaction webs enhances the persistence of plant 
communities. Plos Biol., 4: 129–135. 

Frankie GW, Baker HG, Opler PA (1974). Comparative phenological 
studies of trees in tropical wet and dry forests in lowlands of Costa-
Rica. J. Ecol., 62: 881–919. 

Girão LC, Lopes AV, Tabarelli M (2007). Changes in tree reproductive 
traits reduce functional groups in a riparian landscape. Plos One, 9: 
1–12. 

Hooper DU, Vitousek PM (1997). The effects of plant composition and 
diversity on ecosystem processes. Science, 277: 1302–1305. 

Howe HF, Smallwood J (1982). Ecology of seed dispersal. Ann. Rev. 
Ecol. Syst., 13: 201–228.  

Hubbell SP (2005). Neutral theory in community ecology and the 
hypothesis of functional equivalence. Funct. Ecol., 19: 166–172  

Kilca RV, Schiavini I, Araújo GM (2009). Edaphic and structural 
differences between two seasonal forests in the Cerrado biome. Neo. 
Biol. Conserv., 4: 150–163. 

Koppen W (1948). Climatologia: com um estúdio de los climas de la 
terra. Fondo de Cultura Econômica, México.  

Leishman MR, Westoby M (1992). Classifying plants into groups on the 
basis of associations of individual traits evidence from Australian 
semi-arid woodlands. J. Ecol., 80: 417–424. 

Lord JM, Norton DA (1990). Scale and the spatial concept of 
fragmentation. Conserv. Biol., 4: 197–262. 

Loreau  M  (2000). Biodiversity  and  ecosystem  functioning: recent 
theoretical advances. Oikos, 91: 3–17.  

Loreau M, Naeem S, Incheusti P, Bengtsson J, Grime JP, Hector A, 
Hooper DU, Huston MA, Raffaelli D, Schmid B, Tilman D, Wardle DA 
(2001). Ecology - Biodiversity and ecosystem functioning: Current 
knowledge and future challenges. Science, 294: 804–808.  

Mayfield MM, Boni ME, Daily GC, Gretchen CD, Ackerly D (2005). 
Species and functional diversity of native and human-dominated plant 
communities. Ecology, 86: 2365–2372. 

Micheli F, Halpern BS (2005). Low functional redundancy in coastal 
marine assemblages. Ecol. Lett., 8: 391–400.  

Miles L, Newton AC, DeFries RS, DeFries RS, Corinna R, May I, Blynth 
S, Kapos V, Gordon JE (2006). A global overview of the conservation 
status of tropical dry forests. J. Biogeogr., 33: 491–505. 

Myers N, Mittermeier RA, Mittermeier CG (2000). Biodiversity hotspots 
for conservation priorities. Nature, 403: 853–858.  

Oliveira-Filho AT, Ratter JA (2002). Vegetation Physiognomies and 
Woody Flora of the Cerrado Biome. In: Oliveira PS and Marquis RJ 
(eds). The Cerrados of Brazil. Columbia University Press, New York. 

Pearson DL (1971). Vertical stratification of birds in a tropical dry forest.  
Condor., 73: 46–55.  

Pendry CA, Dick J, Pullan MR (2007). In search of a functional flora-
towards a greater integration of ecology and taxonomy. Plant Ecol., 
192: 161–167. 

Petchey OL (2004). On the statistical significance of functional diversity 
effects. Funct. Ecol., 18: 297–303.  

Petchey OL, Gaston KJ (2002a). Extinction and the loss of functional 
diversity. Proc. Royal Soc. B-Biol. Sci., 269: 1721–1727.  

Petchey OL, Gaston KJ (2002b). Functional diversity (FD), species 
richness and community composition. Ecol. Lett., 5: 402–411. 

Petchey OL, Gaston KJ (2006). Functional diversity: Back to basics and 
looking forward. Ecol. Lett., 9: 741–758.  

Poorter L, Bongers F (2006). Leaf traits are good predictors of plant 
performance across 53 rain forest species. Ecology, 87: 1733–1743.  

Poorter L, Bongers L, Bongers F (2006). Architecture of 54 moist-forest 
tree species: Traits, trade-offs, and functional groups. Ecology, 87: 
1289–1301. 

Ratter JA (1992). Transitions between cerrado and forest vegetation in 
Brazil. In: Furley PA, Proctor J and Ratter JA (eds) Nature and 
Dynamics of Forest-Savanna Boundaries. Chapman and Hall, 
London.  

Richards PW (1996). The tropical rain forest: An ecological study. 
Cambridge University Press, New York. 

Sanchez-Azofeifa GA, Kalacska M, Quesada M (2005). Need for 



11 

 

 
 
 

 
integrated research for a sustainable future in tropical dry forests.  

Conserv. Biol., 19: 285–286.  
Scariot A, Sevilha AC (2005). Biodiversity, structure and conservation of 

deciduous forests in the Cerrado. In: Scariot, A., Felfili, J. M., Souza-
Silva, J. C. (Org.). Savannah: Ecology, Biodiversity and 
Conservation. Brasilia: Ministry of Environment.  

Shepherd GJ (2004). FITOPAC-Shell 1.6.4. State University of 
Campinas, Campinas. 

Siqueira AS, Araújo GM, Schiavini I (2009). Tree component structure 
and soil characteristics of two fragments of deciduous forest in the 
river valley Araguari, MG, Brazil. Acta Bot. Bras., 23: 10–21. 

Skov F (2000). Distribution of plant functional attributes in a managed 
forest in relation to neighbourhood structure. Plant Ecol., 146: 121– 
130. 

Smith MD, Knapp AK (2003). Dominant species maintain ecosystem 
function with non-random species loss. Ecol. Lett., 6: 509–517.  

Swaine MD, Whitmore TC (1988). On the definition of ecological 
species groups in tropical rain forests. Vegetation, 75: 81–86.  

Swenson NG, Enquist BJ (2007). Ecological and evolutionary 
determinants of a key plant functional trait: Wood density and its 
community-wide variation across latitude and elevation. Am. J. Bot., 
94: 451–459. 

Tilman D, Knops J, Wedin D, Reich P, Ritchie M, Siemann E (1997). 
The influence of functional diversity and composition on ecosystem 
processes. Science, 277:1300–1302. 

Tilman D, Reich PB, Knops J, Wedin D, Mielke T, Lehman C (2001).  
Diversity  and  productivity  in  a  long-term  grassland  experiment.  
Science, 294: 843–845.  

Tweddle JC, Dickie JB, Baskin CC, Baskin JM (2003). Ecological 

aspects of seed desiccation sensitivity. J. Ecol., 91: 294–304. 

 
 
 
 

 
Vale VS, Schiavini I, Lopes SF, Dias Neto OC, Oliveira AP, Gusson AE 

(2009). Floristic composition and structure of the tree component in a 
remnant of primary forest in semideciduous Araguari, Minas Gerais, 
Brazil. Hoehnea, 36: 417–429.  

Veloso HP, Rangel Filho AL, Lima JCA (1991). Classification of 
Brazilian vegetation adapted to a universal system. IBGE, Rio de 
Janeiro. 

Walker B, Kinzig A, Langridge J (1999). Plant attribute diversity, 
resilience, and ecosystem function: The nature and significance of 
dominant and minor species. Ecosyst., 2: 95–113. 

Walker BH (1992). Biodiversity and Ecological Redundancy. Conserv. 
Biol., 6: 18–23. 

Walther BA (2002). Grounded ground birds and surfing canopy birds: 
Variation of foraging stratum breadth observed in neotropical forest 
birds and tested with simulation models using boundary constraints. 
Auk., 119: 658–675.  

Walther BA, Clayton DH, Gregory RD (1999). Showiness of neotropical 
birds in relation to ectoparasite abundance and foraging stratum. 
Oikos, 87: 157–165. 

Wikander T (1984). The dispersal mechanism of the distribution of life 
forms in a deciduous forest of Venezuela. Biotropica, 16: 276–283.  

Yamamoto LF, Kinoshita LS, Martins FR (2007). Pollination syndromes 

and dispersal in fragments of tropical semideciduous forest, Brazil. 

Acta Bot. Bras., 21: 553–573. 


