Diversity In Secondary Forests Research Articles

Short-term effects of understory removal on understory diversity and biomass of temperate forests in northeast China

IntroductionUnderstory removal is a traditional practice in forest management to reduce fire risk and promote seedling regeneration. However, its effect on understory diversity, biomass and soil nutrients in temperate forest ecosystems is less known, which limits our assessment of the effectiveness of understory vegetation management.MethodsWe quantified the composition of the understory species, their diversity, and the biomass of the understory and factors driving changes in these parameters in primary mixed broad-leaved Pinus koraiensis forest (BKF), secondary Betula platyphylla forest (BF), and Larix gmelinii plantation (LF) in northeast China after a 5-year understory removal.ResultsAfter understory removal, the number of shrub and herb species in BKF and LF decreased, while the number of shrub species in BF increased significantly and that of herb species decreased; the species with strong light preference, Equisetum hyemale, Impatiens noli-tangere, and Filipendula Palmata, were dominant in the herb layer of the three forest types; Shannon–Wiener diversity, Pielou evenness, and Simpson diversity of the herb layer in LF increased significantly (P < 0.05), while those of the shrub and herb layers in BF and LF showed no significant changes (P > 0.05). The total understory biomass of understory of BKF and LF decreased by 0.94 t·hm−2 and 1.32 t·hm−2, respectively, while that of BF increased by 1.31 t·hm−2; soil NH4+-N and total phosphorus (TP) were the key factors regulating understory vegetation diversity and biomass, respectively.ConclusionThese results suggest that understory removal is a beneficial management strategy for increasing shrub biomass and diversity in secondary forests, while it should be avoided in primary forests and plantations to prevent the reduction of understory plant diversity and soil nutrient loss.

A Floristic Assessment of Woody Plant Diversity in Secondary Forest, Ile-Ife Nigeria: A Proactive Step to Monitoring the Diversity Loss and Degradation

Loss of biodiversity has been recognized as one of the main threats to the forest ecosystem. This study examined the diversity and conservation status of woody species in the secondary forest of Obafemi Awolowo University, Ile-Ife, Nigeria using six permanent plots. All woody species were completely enumerated, and identified; their girths at breast height were measured at 1.3 m above buttress. Biodiversity status was assessed using Shannon-Wiener diversity, evenness of distribution, Sorrenson index of similarity and species importance value index. There were 77 tree species distributed into 62 genera and 30 families. The most abundant species were Celtis zenkeri and Lecaniodiscus cupanioides, while the most abundant families were Moraceae, Euphorbiaceae, and Fabaceae. The tree species density ranged from 508 – 1132 plants per hectare. The Shannon-Weiner diversity index (1.83 to 3.50), evenness (0.483 – 0.741) and the basal area (6.06 – 25.73 m2 ha-1) were high in the forest. However, Celtis mildbraedii is critically endangered, while Garcina kola, Mallotus oppositifolus and Ricinodendron heudelotii are vulnerable. This study provides baseline diversity data for the conservation of woody species in the forest and concludes that this secondary forest is a potential biodiversity hub if properly managed. It will also play a key role in fashioning out realistic, appropriate, and effective conservation strategies that will enhance the restoration and management of the floristic composition of the secondary forest.

Functional trait profiles and diversity of trees regenerating in disturbed tropical forests and agroforests in Indonesia

A main question in restoration of degraded forests and forest landscapes recovering from logging and fire is what to expect from natural regeneration through surviving propagules in the soil or seed sources and associated dispersal agents from the surrounding landscape mosaic, as alternative to tree planting. Tree diversity in secondary forests may be high, but based on newcomer species of low wood density and long-distance, abiotic dispersal modes. We compiled and analyzed three pairs of case studies (totaling 815 plots and 11.8 ​ha) of secondary forests recovering from logging, fire and conversion to agroforest in Sumatra and Kalimantan (Indonesia) on mineral soils. Data on tree species diversity, wood density frequency distribution (indicative of successional status) and dispersal modes were compared with those of less disturbed comparator forests in the same landscapes. Relatively undisturbed lowland dipterocarp forest in Kalimantan had close to 200 species of trees (>10 ​cm diameter) at a 1-ha sample scale (and 450 ​at a 10-ha scale). After repeated fires a sample area of 2 ​ha was needed to reach the same species richness. Regulation-based logging had little impact on tree species richness. In rubber agroforest with low-intensity management beyond rubber planting, 50 tree species were found at a 1-ha scale and close to 100 species in 3 ​ha. The Kalimantan forest after repeated fires had a markedly higher fraction of low-wood-density trees (40%), but otherwise, all forests sampled were similar in overall wood density profiles. Selectively logged forest managed by a local community (village forest) and rubber agroforest in Sumatra contained larger fractions of heavy-wood-density trees. The majority of trees (50%–70%) had birds, bats and primates as dispersal agents in all sites. Selectively logged forests had higher fractions of autochorous species (15%) compared to other sites. Anemochorous (wind-dispersed) species, especially Macaranga lowii, were most common (20%) in lowland dipterocarp forest. Comparison between secondary forests and agroforests showed the influence of farmer selection regarding what is allowed to grow beyond the pole stage. Wood density and seed dispersal profiles can be used as degradation indicators of species assemblages across various disturbance levels and types, as they reflect the habitat quality of the surrounding landscape mosaics.

Large wild herbivores slow down the rapid decline of plant diversity in a tropical forest biodiversity hotspot

Abstract The UN declaration of the Decade of Ecosystem Restoration 2021–2030 emphasizes the need for effective measures to restore ecosystems and safeguard biodiversity. Large herbivores regulate many ecosystem processes and functions; yet, their potential as a nature‐based solution to buffer against long‐term temporal declines in biodiversity associated with global change and restore diversity in secondary forests remains unknown. By means of an exclusion experiment, we tested experimentally the buffering effects of large wild herbivores to avert against long‐term biodiversity collapse in old‐growth and secondary tropical forests in the Atlantic Forest of Brazil where sapling abundance and species richness declined c. 20% over the course of 10 years. The experiment comprised 50 large herbivore exclosure‐open control plot pairs (25 at the old‐growth forest and 25 at the secondary forest), where 2 m2 were monitored in every plot during a 10‐year period. Large herbivores were able to decelerate diversity declines and compositional change in the species‐rich old‐growth forest, but only decelerated compositional change in the secondary forest. In contrast, declines in species richness and abundance were unaffected by large herbivores on either forest. The buffering effects of large herbivores were strongly nonlinear and contingent on the initial level of diversity at the patch scale: highly diverse communities suffered the strongest collapse in the absence of large herbivores. Thus, larger buffering effects of large herbivores on the old‐growth forest are the logical consequence of large herbivores buffering the many high diversity plant communities found in this forest. Conversely, as the secondary forest held fewer high diversity patches, buffering effects on the secondary forest were weak. Synthesis and applications. Our study indicates that large herbivores have moderate yet critical effects on slowing down community change and diversity loss of highly diverse plant communities, thus suggesting that the conservation of (and potentially trophic rewilding with) large herbivores is a fundamental nature‐based solution for averting the global collapse of the strongholds of biodiversity. Its buffering effects on biodiversity loss operate at very small spatial scales, are likely contingent on successional stage and are most effective in old‐growth or high diversity secondary forests.

Sucessional trajetories of bird assemblages in amazonian secondary forests: Perspectives from complementary biodiversity dimensions

Secondary forests occupy extensive areas in tropical regions, providing an opportunity to investigate their relevance to biodiversity restoration. However, determining the conservation value of secondary forests and evaluating their successional trajectories depends on how biodiversity is measured. Here, we explore different biodiversity dimensions to understand how bird assemblages recover from forest disturbance caused by small scale farmers in the Amazon. We sampled bird species through standard visual and auditory censuses in 24 small plots of 1-hectare distributed in a paired design of old growth forests and secondary forests from different age categories (early, middle and late succession). We used 12 biodiversity metrics to explore the taxonomic, functional, and phylogenetic dimensions of bird diversity. Total species richness and evenness was similar between secondary and old growth forests. In contrast, the number of passerine species and disturbance-vulnerable species were higher in the controls of old growth forests compared to secondary forests. The relative abundance of birds with distinct functional traits consistently differed between the secondary forests of different age categories and their old growth forest counterparts. Functional evenness and divergence increased with canopy height and basal area through forest regeneration. In contrast, bird phylogenetic diversity in secondary forests was higher compared to those found in old growth forests while accounting for forest types and age categories of secondary forests. Bird species tolerant to disturbances partially compensate the loss of avian taxonomic and phylogenetic diversity during the conversion of undisturbed forests to agricultural fields. Changes in functional evenness and functional divergence suggest that resources used by birds are altered along the secondary succession and that the niche complementarity among species is reduced in more intensively managed sites. Ecological succession can be highly complex in terms of taxa identity, their functional roles and evolutionary history. Therefore, measurements that explore distinct biodiversity dimensions are fundamental to understanding how species are organized in assemblages across time and space.

Enhancing Plant Diversity in Secondary Forests

Dispersal, recruitment and establishment limitations are crucial processes shaping forest composition. In secondary forests these mechanisms may operate differently than in mature forests, because young and isolated secondary forests may suffer stronger limitations due to a lack of suitable dispersers and harsh environmental conditions— such as the elevated competition of exotic grasses. To assess establishment limitations in these forests, we undertook transplant experiments involving seeds and seedlings along a chronosequence of secondary forests in tropical Australia. The experiments included six species that varied in seed size (6–50 mm in length) and successional status (early to late successional). Seeds of five species were placed in one of three treatments: (1) exposed seeds, (2) fenced seeds, and (3) buried seeds, and multiple seedlings of six species were transplanted in block treatments. After 14–17 months, seed from all plant species germinated across all ages of secondary forests. However, in young secondary forest sites (4–12 years) fewer germinated seeds survived. The highest survival rates were observed for buried seeds (27.2%) compared to the low survival of exposed seeds (6.0%). Planted seedlings (6 spp) had the greatest overall survival (63.1%) and the highest growth rates in older secondary forests. We found that species identity was important for growth and survival in both experiments, but detected no effect of successional status or seed size. A crucial finding of this study was that the buried seeds of all species germinated and had relatively high survival irrespective of variation in site conditions or successional status, suggesting that seed availability may be a greater barrier to recovery of secondary forests in the region than the establishment limitations imposed by environmental conditions.

Floristic Diversity in Secondary Forest under Munduruku Indigenous Agroextractivism

Aims: Knowledge is currently low about composition, richness and abundance of native plant species from secondary forests in traditional communities in the Tapajós River Basin, Western Amazon. These forests are of great importance to indigenous populations being niches of resistance to the advances of monocultures. The objective of this work was to evaluate the floristic composition of a secondary forest with typical indigenous extractive interventions.
 Study Design: The secondary forest studied located in indigenous Village. This forest had 15 years of natural regeneration and was therefore an anthropized forest, where the indigenous people removed wood, fibers, oils and fruits, thus characterizing the agroextractivism on this environment and a very particular floristic composition always in evolution.
 Place and Duration of Study: The research was in Santarem city, Pará state, in Ipaupixuna Village (02°32´46” S, 54°20'15” W) between June 2019 to December 2019.
 Methodology: The research had a descriptive approach for floristic study, but in the same time had a quantitative point of view with the use of regression analysis. The parameters evaluated were: 1. Species abundance, 2. Floristic Richness; 3. Plant diversity measured by the Jentsch Mixing Coefficient; 4. Relations between Circumference & Height of trees. The size of the sampled area was 1 (one) hectare of secondary forest.
 Results: A high abundance was found for Tapirira guianensis Aubl followed by Buchenavia huberi Ducke and Bellucia grossularioides (L.) Triana. Fabaceae was the family of greatest quantitative expression in this 15-year-old secondary forest in indigenous landscapes followed by Arecaceae.
 Conclusion: The secondary forest studied of 15 years of natural regeneration and random anthropogenic interventions by agroextractivists activities of Munduruku Indigenous people showed medium floristic richness and low floristic diversity. Interventions to enrich this secondary forest with plant species with high economic potential can bring environmental and economic benefits to these indigenous people.

Diversity and structure of bird communities in contrasting forests of the Hengduan Mountains, China

Rapid economic development has led to high rates of deforestation and widespread alteration of land cover in many regions in China, where many primary forests have been replaced by secondary and plantation forests. Therefore, we aimed to determine differences in bird community diversity and structure between three forest types. We assessed differences in species richness, phylogenetic and functional diversity and community structure of bird communities in primary, secondary and plantation forests. Data was collected over four meteorological seasons from bird communities in a nature reserve in the Hengduan Mountains, China. We found that functional and phylogenetic diversity in secondary forest were significantly greater than in primary forest, while species richness was not significantly different. Thus, simple metrics (i.e. species richness) may not be sufficient to assess forest conservation value. We suggest that it is necessary to use varied diversity metrics that incorporate species’ similarities and differences. It also appears that secondary forests play an important role in the maintenance of studied bird biodiversity. The results of community structure analyses show that the habitat filter was strongest in the primary forest, leading to primary forest species being lighter in weight, shorter in body length, and with longer tarsometatarsus. These species were specialized and forest-dependent, reflecting the value of primary forests as an irreplaceable habitat type for several species after nearby forests are degraded.

Bee diversity in secondary forests and coffee plantations in a transition between foothills and highlands in the Guatemalan Pacific Coast.

BackgroundAlthough conservation of pristine habitats is recognized in many countries as crucial for maintaining pollinator diversity, the contribution of secondary forest conservation is poorly recognized in the Latin American context, such as in Guatemala. San Lucas Tolimán (SLT) is a high-quality coffee production region from the Atitlan Province, which has the second highest deciduous forest cover in Guatemala and pristine forest is prioritized for conservation. In contrast, secondary forest protection is undetermined, since these forests are normally removed or strongly affected by coffee farming practices. This situation may affect the diversity of native pollinators, mainly bees, which usually rely on the secondary forest for food resources.MethodsWe conducted a study to investigate the importance of secondary forests around the SLT coffee plantations (Coffea arabica L.) for pollinators. We compared bee diversity (richness, abundance and composition) in secondary forests of different age and coffee plantations with diverse farming techniques. Being the first study of pollinators in Guatemalan coffee plantations, we also recorded data for an entire year (2013–2014) in order to describe bee seasonality.ResultsWe found significant differences in bee diversity between the coffee plantations and secondary forests, particularly early secondary forests showed higher bee abundances but diversity indices were similar between different vegetation type plots. In the early dry season, secondary forests showed the greatest native bee diversity. During the late dry season, when the coffee was flowering, honey bees were dominant in the same plots. This study provides important management insights to support the conservation of pollinators, since our results offer guidelines to improve coffee production by increasing native pollinator diversity.

Natural recovery of plant species diversity in secondary forests in Eastern Amazonia: contributions to passive forest restoration

Natural regeneration is important in the context of the strategies to recover native vegetation in Brazil and of the international commitments of forest restoration undertaken by the country. However, trajectories of recovery can be highly variable and context-dependent, demanding studies to foster the use of secondary forests in restoration. Here, we describe the natural recovery of plant diversity in a chronosequence (5–21 years old) and how it is influenced by age of the regenerating forests. For this, we sampled the floristic composition and structure in 20 fragments of secondary forest in Southeast Para in 2014 and 2015. Transects of either 10 × 250 m or 20 × 125 m (0.25 ha) were delimited in each forest fragment, and subdivided into 25 subplots of 10 × 10 m, where plants of the upper stratum (DBH ≥ 10 cm) were sampled. The lower stratum (DBH < 10 cm) was sampled in five 5 × 20 m subplots that were nested in the 0.25-ha transects. We recorded 5509 individuals of 282 species and 61 families in the 20 transects evaluated. The species diversity recovery occured rapidly in the first few decades of ecological succession. Floristic composition of the upper stratum was correlated with forest age. Species diversity metrics were predicted by the age and basal area of secondary forests, demonstrating their importance as indicators of successional stages in secondary forests. Our results reinforce the relevance of using secondary forest in restoration programmes across the Amazonian region.

The Road to Functional Recovery: Temporal Effects of Matrix Regeneration on Amazonian Bats

Across the tropics, vast deforested areas are undergoing forest regeneration due to land abandonment. Although secondary forest is an expanding type of landscape matrix that has been shown to buffer some of the negative consequences of forest loss and fragmentation on taxonomic diversity, little is known in this regard about the functional dimension of biodiversity. We took advantage of an ecosystem-wide fragmentation experiment to investigate longer term changes in functional diversity of a mega-diverse Amazonian bat assemblage associated with regrowth development in the matrix. We found that matrix regeneration affected several facets of bat functional diversity in secondary forest over time, increasing functional α diversity, species- and community-level functional uniqueness, altering functional trait composition, and resulting in functional β-diversity changes via trait gains. However, approximately 30 years of matrix regeneration were insufficient for functional diversity to recover to the same levels as in continuous forest. Our results suggest that a combination of natural, human-assisted, and active restoration is likely to be the most successful strategy for restoring functional biodiversity of bats in human-modified tropical landscapes, a finding that most likely also applies to many other taxa.

A Forest's Second Life.

The article discusses the biological aspects and diversity of secondary forests, Emphasis is given to topics such as the reforestation of logged tracts of land, the biodiversity of the Manu Biosphere Reserve in Peru, the impact of secondary-growth forests on carbon dioxide pollution, and a pledge to restore degraded forest at a climate summit of the United Nations.

Generic Composition, Structure and Diversity of Secondary Forests at Amisconde, the Pacific Slope of the Cordillera de Talamanca, Costa Rica

Most Costa Rican forests have been intensively studied in recent years. One exception is the transition zone from lowland wet forest to the high elevatíon Quercus forest belt al Ihe pacific slopes of the Cordillera de Talamanca. An inventory of secondary forest composition, structure and diversity was done on a specific slope (l150- 2300-m elevation) in the conservation and development project Amisconde. Thirteen plots of 500 m2 were evenly spread a10ng an elevation gradient. Specimens were collected of a11 woody individuals (&gt; 3 cm DBH), dried, placed in a herbarium of morphospecies and afterwards identified. In total 90 genera within 49 families were found. The vegetation was separated in three forest types using TWINSPAN c1assification. Forest types were elevatíon based. Elevation and forest age showed (overall) no correlatíon with diversity using ANOVA, with the single exceptíon of a positíve correlatíon of the number of genera and elevatíon. This was opposite to the negative correlations mostly found on elevatíon gradients. The main factors for this positíve correlation were the level of recent disturbance and the distance to primary forest, in combination wíth forest age

Diversidad y composición de murciélagos frugívoros en bosques secundarios de Tabasco, México

We captured bats using mist nets in 4 secondary forests that represent a perturbation gradient in Southeast Mexico, in order to compare frugivore bat species richness, diversity and composition. We captured 691 frugivorous bats from 15 species; Artibeus jamaicensis (A. jamaicensis) and Sturnira lilium (S. lilium) were the most abundant. There were no significant differences in frugivorous bat richness and diversity in secondary forests, although species composition was notably different, S. lilium, A. jamaicensis, Glossophaga soricina, Artibeus lituratus and Carollia sowelli contributed the most to differences. Secondary forests are important for frugivorous bats conservation and in general for wildlife, since they are the last refuges in the Tabasco coastal plain, a region dominated by grasslands and urban areas.

Persistence of genetic variation in recolonizedTsuga canadensis(Eastern hemlock) populations following historic forest clearance

The recovery of genetic variation in newly recolonized populations is an important concern in forest conservation genetics. We examined the potential recovery of genetic diversity and changes to genetic structure in populations of the wind-pollinated species Tsuga canadensis that naturally regenerated following the extensive 19th century regional forest clearance for agriculture in west-central Massachusetts. We genotyped 264 individuals across six microsatellite loci and compared levels and patterns of genetic variation between primary forests (forests that were logged but never cleared) and secondary forests (stands that were recolonized following agricultural abandonment). We found no significant reductions in genetic diversity in secondary forests (AR = 5.450; HS = 0.718) compared to primary forests (AR = 5.742; HS = 0.730). Moreover, the population genetic differentiation was also not significantly reduced in secondary compared to primary forests, with no significant genetic structure observed among all populations. These results suggest rapid genetic recovery of T. canadensis populations in recolonized forests compared with other late-successional temperate tree species.

Why are there more arboreal ant species in primary than in secondary tropical forests?

1. Species diversity of arboreal arthropods tends to increase during rainforest succession so that primary forest communities comprise more species than those from secondary vegetation, but it is not well understood why. Primary forests differ from secondary forests in a wide array of factors whose relative impacts on arthropod diversity have not yet been quantified. 2. We assessed the effects of succession-related determinants on a keystone ecological group, arboreal ants, by conducting a complete census of 1332 ant nests from all trees with diameter at breast height ≥ 5 cm occurring within two (unreplicated) 0·32-ha plots, one in primary and one in secondary lowland forest in New Guinea. Specifically, we used a novel rarefaction-based approach to match number, size distribution and taxonomic structure of trees in primary forest communities to those in secondary forest and compared the resulting numbers of ant species. 3. In total, we recorded 80 nesting ant species from 389 trees in primary forest but only 42 species from 295 trees in secondary forest. The two habitats did not differ in the mean number of ant species per tree or in the relationship between ant diversity and tree size. However, the between-tree similarity of ant communities was higher in secondary forest than in primary forest, as was the between-tree nest site similarity, suggesting that secondary trees were more uniform in providing nesting microhabitats. 4. Using our rarefaction method, the difference in ant species richness between two forest types was partitioned according to the effects of higher tree density (22·6%), larger tree size (15·5%) and higher taxonomic diversity of trees (14·3%) in primary than in secondary forest. The remaining difference (47·6%) was because of higher beta diversity of ant communities between primary forest trees. In contrast, difference in nest density was explained solely by difference in tree density. 5. Our study shows that reduction in plant taxonomic diversity in secondary forests is not the main driver of the reduction in canopy ant species richness. We suggest that the majority of arboreal species losses in secondary tropical forests are attributable to simpler vegetation structure, combined with lower turnover of nesting microhabitats between trees.

Bryophyte Species Diversity in Secondary Forests Dominated by the Introduced SpeciesSpathodea campanulataBeauv. in Puerto Rico

The introduced tree species Spathodea campanulata (Bignoniaceae) forms novel forests in Puerto Rico, these having emerged after the abandonment of ! elds in the mid-20th century and resulting in forests with a new species composition. We assessed bryophyte species richness in these novel forests and sought correlations with geological substrate, past land use, forest edge and patch area, forest structure, elevation, microhabitat diversity, tree species richness, and microclimatic conditions. Transects were established (edge and forest interior) in nine moist forest patches dominated by Spathodea in north-central Puerto Rico. These Spathodea forest patches ranged from 0.6 to 9 ha. ANOVA, Chi-square, correlation, and cluster analyses were used in data analyses. We found 57 bryophyte species. There was a signi! cant difference in bryophyte richness among patches. Those on karst exhibited highest bryophyte richness due to microhabitat diversity, past land use, and shorter hydroperiods. Alluvial sites scored lowest in bryophyte species richness, and forest structure was important for bryophyte communities on these sites. Signi! cant differences in temperature, relative humidity, and light intensity were observed between edge and forest interior. These appeared important for establishing bryophyte species cover but not richness and composition. Microhabitat diversity, patch area, and forest age were more related to bryophyte species richness than elevation, exposed edge, and tree species richness, regardless of geologic substrate. Collectively, Spathodea patches were similar to mature forests on the Island with respect to bryophyte species richness and composition. Novel Spathodea forests have conservation value due to their habitat suitability for bryophyte communities.

Influence of Post‐Clearing Treatment on the Recovery of Herbaceous Plant Communities in Amazonian Secondary Forests

Secondary forests are an increasingly common feature in tropical landscapes worldwide and understanding their regeneration is necessary to design effective restoration strategies. It has previously been shown that the woody species community in secondary forests can follow different successional pathways according to the nature of past human activities in the area, yet little is known about patterns of herbaceous species diversity in secondary forests with different histories of land use. We compared the diversity and abundance of herbaceous plant communities in two types of Central Amazonian secondary forests—those regenerating on pastures created by felling and burning trees and those where trees were felled only. We also tested if plant density and species richness in secondary forests are related to proximity to primary forest. In comparison with primary forest sites, forests regenerating on non‐burned habitats had lower herbaceous plant density and species richness than those on burned ones. However, species composition and abundance in non‐burned stands were more similar to those of primary forest, whereas several secondary forest specialist species were found in burned stands. In both non‐burned and burned forests, distance from the forest edge was not related to herbaceous density and species richness. Overall, our results suggest that the natural regeneration of herbaceous species in secondary tropical forests is dependent on a site's post‐clearing treatment. We recommend evaluating the land history of a site prior to developing and implementing a restoration strategy, as this will influence the biological template on which restoration efforts are overlaid.

Loss of functional diversity of ant assemblages in secondary tropical forests

Secondary forests and plantations increasingly dominate the tropical wooded landscape in place of primary forests. The expected reduction of biodiversity and its impact on ecological functions provided by these secondary forests are of major concern to society and ecologists. The potential effect of biodiversity loss on ecosystem functioning depends largely on the associated loss in the functional diversity of animal and plant assemblages, i.e., the degree of functional redundancy among species. However, the relationship between species and functional diversity is still poorly documented for most ecosystems. Here, we analyze how changes in the species diversity of ground-foraging ant assemblages translate into changes of functional diversity along a successional gradient of secondary forests in the Atlantic Forest of Brazil. Our analysis uses continuous measures of functional diversity and is based on four functional traits related to resource use of ants: body size, relative eye size, relative leg length, and trophic position. We find a strong relationship between species and functional diversity, independent of the functional traits used, with no evidence for saturation in this relationship. Recovery of species richness and diversity of ant assemblages in tropical secondary forests was accompanied by a proportional increase of functional richness and diversity of assemblages. Moreover, our results indicate that the increase in functional diversity along the successional gradient of secondary forests is primarily driven by rare species, which are functionally unique. The observed loss of both species and functional diversity in secondary forests offers no reason to believe that the ecological functions provided by secondary forests are buffered against species loss through functional redundancy.

Tree Species Diversity in Secondary Forest of Visayas State University Forest Reservation, Philippines

The study was conducted to determine species diversity and similarity within a two-hectare secondary forest of the Visayas State University forest reservation. The diversity value of trees ranged from 3.09 - 4.53. Results of the study indicate that the middle layer of both blocks was observed as the most luxuriant among all layers. A total of 173 species in 113 genera and 51 families; and 92 species, in 69 genera and 37 families were recorded in the middle layer of Block 1 and Block 2, respectively. The genus Ficus of the family Moraceae was identified as the most highly represented in terms of species in both blocks. Moreover, results of the study show that species richness increased within an increasing area but with a decreasing number of species. As to species similarities, it was discovered that 28% of the identified specieds are common to both blocks.