Forest Diversity and Management

Forest coffee areas are hotspots areas for conservation of biodiversity due to anthropogenic effect on diversity and abundance of indigenous species. This study was aimed to determine the effect of forest coffee management on woody species diversity and composition. The study was conducted in Dellomena and Harenna Buluk districts where natural forest and forest coffee are found adjacently. Systematic sampling method was used to collect woody species data from 16 transect lines. Eighty (80) sample quadrats of 20 m × 20 m quadrat size for mature trees/shrubs and five 5 m × 5 m subplots within each quadrat for saplings and seedlings were used. Forty-seven species of 29 families and 39 species of 24 families were recorded in natural forest and forest coffee areas respectively. Woody species frequently recorded in most of the sample plots were Celtis africana (100%), Podocarpus falcatus (95%), Strychnos mitis (95%), Diospyros mespili-formis (95%) and Diospyros abyssinica (90%) in the natural forest, and Celtis africana (95%) and Podocarpus falcatus (95%) in the forest coffee. Woody species richness (P = 0.000), Shannon diversity (P = 0.000), Simpson diversity indices (P = 0.02) and dominance (P = 0.02) were sig-nificantly varied between the two forests. This findings revealed significantly higher woody species diversity and richness in natural forest than forest coffee. Negative effects were noticed due to coffee management practices on woody species diversity and composition in forest coffee areas. Hence, reducing the human pressure on forest coffee via awareness raising and training on the effect of coffee management activities and introduction of environmentally friendly forest coffee management techniques are crucial to maintain ecological service and economic benefit of the forest coffee.

Although species richness has been hypothesized to be highest at 'intermediate' levels of disturbance, empirical studies have demonstrated that the disturbance-diversity relationship can be either negative or positive depending on productivity On the other hand, hypothesized productivity diversity relationships can be positive, negative or unimodal, as confirmed by empirical studies. However, it has remained unclear under what conditions each pattern is realized, and there is little agreement about the mechanisms that generate these diverse patterns. In this study, I present a model that synthesizes these separately developed hypotheses and shows that the interactive effects of disturbance and productivity on the competitive outcome of multispecies dynamics can result in these diverse relationships of species richness to disturbance and productivity The predicted productivity diversity relationship is unimodal but the productivity level that maximizes species richness increases with increasing disturbance. Similarly, the predicted disturbance diversity relationship is unimodal but the peak moves to higher disturbance levels with increasing productivity Further, these patterns are well explained by the opposite effects of productivity and disturbance on competitive outcome that are suggested by the change in community composition along these two environmental gradients: higher productivity favours superior competitors while higher disturbance levels favour inferior competitors.

Gastropod diversity in aspen stands in coastal northern Sweden

This study aims to examine woody species composition, structure, and diversity of Tree-based agroforestry systems in the mid-highlands, Konawe Regency, Southeast Sulawesi Province, Indonesia. Data was collected in each observation plot in the agroforestry patterns. The total number of observation plots was thirty-three. The plot sizes for saplings 5m x 5m, poles 10m x 10m, and trees 20m x 20m. The results found there were 31 plant species composition belonging to 18 families. Plant species at the tree level 73%, herbaceous 10% and shrubs 17%, native endemic species 74%, and introduced 26%. A total of 77% of plant species were planted and 23% of species grew wild. The structures tree level vegetation with the highest importance value index (IVI) was the Tectona grandis species with IVI 144.9, the pole layers were Tectona grandis with IVI 126.7, and the sapling layers were Theobroma cacao with IVI 94.0. While the structures tree level vegetation with the lowest IVI was Artocarpus heterophyllus with IVI 13.4, the pole layers were Mangifera indica with IVI 13.2, and the sapling layers were Syzygium polyanthum and Citrus aurantiifolia with IVI 15.5. The highest species diversity index in the agroforestry of community forest was 1.7. Species richness index (M') and evenness index (E') were evenly distributed all in the agroforestry patterns with moderate criteria. The findings research show that agroforestry systems in the study area are diverse, with the different wood species compositions and structures. Keywords: Agroforestry, composition, community forest, konawe regency, species diversity, structure, southeast Sulawesi, vegetation.

Community structure and ant species diversity across select sites of Western Ghats, India

Characteristics of the early secondary succession after landslides in a broad-leaved deciduous forest in the south Minshan Mountains

Aim Tropical rain forests are often regarded as pristine and undisturbed by humans. In Central Africa, community‐wide disturbances by natural causes are rare and therefore current theory predicts that natural gap phase dynamics structure tree species composition and diversity. However, the dominant tree species in many African forests recruit poorly, despite the presence of gaps. To explain this, we studied the disturbance history of a species‐rich and structurally complex rain forest.Location Lowland rain forest in Southern Cameroon.Methods We identified the recruitment conditions of trees in different diameter classes in 16 ha of species‐rich and structurally complex ‘old growth’ rain forest. For the identification of recruitment preference we used independent data on the species composition along a disturbance gradient, ranging from shifting cultivation fields (representing large‐scale disturbance), to canopy gaps and old growth forest.Results In nine of sixteen 1‐ha forest plots the older trees preferred shifting cultivation fields for recruitment while younger trees preferred gaps and closed forest conditions. This indicates that these nine sites once experienced large‐scale disturbances. Three lines of evidence suggest that historical agricultural use is the most likely disturbance factor: (1) size of disturbed and undisturbed patches, (2) distribution of charcoal and (3) historical accounts of human population densities.Main conclusions Present‐day tree species composition of a structurally complex and species‐rich Central African rain forest still echoes historical disturbances, most probably caused by human land use between three to four centuries ago. Human impact on African rain forest is therefore, contrary to common belief, an issue not of the last decades only. Insights in historical use will help to get a more balanced view of the ‘pristine rain forest’, acknowledging that the dualism between ‘old growth’ and ‘secondary’ forest may be less clear than previously thought.

Conventional conservation policies in Europe notably rely on the passive restoration of natural forest dynamics by setting aside forest areas to preserve forest biodiversity. However, since forest reserves cover only a small proportion of the territory, conservation policies also require complementary conservation efforts in managed forests in order to achieve the biodiversity targets set up in the Convention on Biological Diversity. Conservation measures also raise the question of large herbivore management in and around set-asides, particularly regarding their impact on understory vegetation. Although many studies have separately analyzed the effects of forest management, management abandonment, and ungulate pressure on forest biodiversity, their joint effects have rarely been studied in a correlative framework. We studied 212 plots located in 15 strict forest reserves paired with adjacent managed forests in European France. We applied structural equation models to test the effects of management abandonment, stand structure, and ungulate pressure on the abundance, species richness, and diversity of herbaceous vascular plants and terricolous bryophytes. We showed that stand structure indices and plot-level browsing pressure had direct and opposite effects on herbaceous vascular plant species diversity; these effects were linked with the light tolerance of the different species groups. Increasing canopy cover had an overall negative effect on herbaceous vascular plant abundance and species diversity. The effect was two to three times greater in magnitude than the positive effects of browsing pressure on herbaceous plants diversity. On the other hand, a high stand density index had a positive effect on the species richness and diversity of bryophytes, while browsing had no effect. Forest management abandonment had few direct effects on understory plant communities, and mainly indirectly affected herbaceous vascular plant and bryophyte abundance and species richness and diversity through changes in vertical stand structure. Our results show that conservation biologists should rely on foresters and hunters to lead the preservation of understory vegetation communities in managed forests since, respectively, they manipulate stand structure and regulate ungulate pressure. Their management actions should be adapted to the taxa at stake, since bryophytes and vascular plants respond differently to stand and ungulate factors.

ABSTRACTPlantation forests are becoming an increasingly important component of the world’s forested ecosystem. However, relatively little is known about how forest plantation management, overstory tree species composition and diversity impact biodiversity of nontree components of the forest. We assessed changes in ant functional group composition as related to changes in overstory tree diversity (monocultures vs. polycultures), species composition (native African species vs. exotic teak), and time (one and two years after planting). A pitfall trapping scheme was implemented during the summer months of 2006 and 2007. A total of 7473 specimens were collected representing six subfamilies, 22 genera, and 65 species. We found no significant differences in traditional diversity measures or functional group composition between treatments one year after planting. Two years after planting, we found that species richness of ground foraging ants had significantly increased (F = 4.60, d.f. = 4, 15, p = 0.01). Several observed trends may have indicated that these ant communities were in transition and will likely become more distinct over time as the different plantation types recover from disturbance and diverge from each other in overstory structure.EDITED BY Sheila Ward

Tree diversity, distribution and regeneration in major forest types along an extensive elevational gradient in Indian Himalaya: Implications for sustainable forest management

AimsRemote‐sensing approaches could be beneficial for monitoring and compiling essential biodiversity data because they are cost‐effective and allow for coverage of large areas over a short period. This study investigated the relationship between multispectral remote‐sensing data from Landsat 8 and Sentinel‐2 and species richness and diversity in mountainous and protected grasslands.LocationsGolden Gate Highlands National Park, Free State, South Africa.MethodsIn‐situ data of plant species composition and cover from 142 plots with 16 relevés each were distributed across the study site and used to calculate species richness and Shannon–Wiener species diversity index (species diversity). We used a machine‐learning random forest algorithm to optimize the prediction of species richness and diversity. The algorithm was used to identify the optimal spectral bands and vegetation indices for estimating species richness and diversity. Subsequently, the selected bands and vegetation indices were used to estimate species richness through random forest regression.ResultsThis research found weak relationships between remote‐sensing vegetation indices and the diversity metrics, but significant relationships were found between some spectral bands and diversity metrics. Moreover, using machine‐learning random forest, the multispectral data sets exhibited strong predictive powers. In this investigation, near‐infrared (NIR) seemed to be the most selected band for both sensors to explain species diversity in mountainous grasslands.Main conclusionsThis finding further ascertains the efficiency of optimizing high spatial resolution spectral information to estimate plant species richness and diversity. This research shows that NIR, Soil‐Adjusted Vegetation Index (SAVI) and Enhanced Vegetation Index (EVI) are the most adequate for predicting species richness and diversity in mountainous grasslands with relatively good accuracies. Plant phenology and the choice of sensor affect the relationship between spectral information and species diversity variables.

The role of sacred forest/sacred groves in the conservation of biodiversity is well recognised and documented. Despite the importance of sacred forests in conservation, data of flora species composition and diversity in many sacred forests still remain scanty. The study was conducted to provide baseline data on tree species composition and diversity of Ipinu-Igede sacred forest with a view to promote the role of sacred forest in flora conservation in the area. Systematic sampling technique was adopted for the study. A base line transect of 2 km long was established and five (5) other transects 2 km long were laid at regular interval of 500 km apart. On each transect, 4 sampling plots of 50 mx50 m were established at a regular interval of 500m apart. Within the 50 m x50 m plots, trees with diameter at breast height (DBH)≥10 cm were identified and enumerated. Species Important Value Index (IVI), species richness, species evenness and species diversity were estimated. A total number of 50 tree species in 19 families were recorded. Cola gigantea was the most important tree species with IVI of 14.56, this was followed by Harungana madagascariensis with 13.14. Caesalpinioideae was the dominant family with 6 species, 48.15% of the families were represented by only one species. The species richness was D=9.436, Species Evenness was E´=0.7668 and species diversity was H=3.646. Thirty percent (30%) of the tree species were in the DBH class of 1-40cm indicating good regeneration status of the sacred forest. Acknowledgement of the traditional practices by scientists and other actors in natural resources conservation will help in promoting forest conservation.

The regressive succession model hypothesizes tropical savanna‐woodlands to be a degraded stage of primary deciduous forests. Species diversity, richness and evenness of woody species in savanna‐woodlands, secondary deciduous forests and mature deciduous forests of central India were compared to test if the regressive succession explained pattern in species richness, diversity, functional diversity and basal area. At the plot scale (0.1 ha) secondary deciduous forests and savanna‐woodlands had similar species diversity, a pattern not consistent with the regressive model of deciduous forest succession, and mature deciduous forests had greater species diversity and richness (p<0.05). When examined at a larger scale or community scale by pooling all plots within a community type, the trend in diversity persisted even with greater effort allocated to sampling of secondary deciduous forests. Species richness at the community scale was greatest in secondary deciduous forest as expected from species area relationship. The communities shared 28 woody species but the species composition was significantly different between the communities. I suggest that conservation of tropical deciduous forests based on regressive succession model is problematic.

The number of species is known to decrease from the humid tropics towards drier and colder climates, but how species richness varies along environmental and spatial gradients within the tropical rain forests is not clear. We inventoried 214 transects of 0.25 ha to document species diversity patterns in an example plant group (ferns and lycophytes) across non‐inundated rain forests of western and central Amazonia, and assessed how well these conformed with proposed hypotheses about species richness. The observed number of species varied between 6 and 71 per transect. The effective number of species (emphasising the degree of unevenness in species abundances) varied between 1.02 and 8.60, and diversity profiles revealed considerable differences among transects in community structure. Although the density of individuals varied over almost two orders of magnitude, species diversity was better explained by other variables. In particular, within‐transect species diversity increased substantially with increasing soil cation concentration. It also increased with soil aluminium concentration, heterogeneity in soil chemistry, annual rainfall and dry season rainfall, and was higher in western than in central Amazonia. Multiple regression models explained up to 70% of the variance in species diversity, but the relationships between species diversity and the environmental gradients became progressively weaker as species abundances were given more weight in the calculation of diversity. Our results conformed to the proposal that site productivity promotes species diversity. This seemed to arise from larger species pools on more fertile soils and in wetter climates, even when it could be expected that the older and more widespread infertile soils would have provided more opportunities for speciation.

The current interest among resource managers in ecosystem management necessitates a better understanding of the response of plant species diversity to forest management practices. This study attempted to assess the effects of one forest management practice–clear‐cutting–on plant biodiversity in a mid‐Appalachian hardwood forest by comparing species composition and diversity between two young (≈ 20 yr following clear‐cutting) and two mature (> 70 yr following selective cutting) watersheds. Sampling was confined to the herbaceous layer (vascular plants ≤ 1‐m in height) and woody overstory (stems ≥ 2.5 cm diameter at 1.5‐m height). The important tree species occurred on all watersheds, but the relative importance of these species varied greatly with stand age. Less shade‐tolerant species, such as black cherry (Prunus serotina) and tulip poplar (Liriodendron tulipifera), are replaced by more‐tolerant species, such as northern red oak (Quercus rubra) and sugar maple (Acer saccharum), as the stand matures. Analysis of tree species richness per plot suggests that the competitive thinning process decreases species evenness as the stand develops. Important herb‐layer species included stinging nettle (Laportea canadensis), violets (Viola spp.), seedling of striped maple (A. pensylvanicum), and several fern species. In sharp contrast with the trees, these species appeared to vary little with stand age. Species diversity (H') did not vary with stand age for either the overstory or the herbaceous layer. Detrended correspondence analysis showed a significant correlation between species composition of the two strata for the mature watersheds, but not the young, clear‐cut watersheds. Thus, we suggest a temporal shift in processes influencing species composition following disturbance from allogenic factors (e.g., soil characteristics) to autogenic factors (e.g., stand characteristics), which lead to a linkage between forest strata later in succession. The degree to which forest management alters species composition in these central Appalachian forest ecosystems may be tied to the degree of alteration of the link between strata.