scholarly journals Edge-Interior Disparities in Tree Species and Structural Composition of the Kilengwe Forest in Morogoro Region, Tanzania

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
David Sylvester Kacholi
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Anthropogenic Activities ◽  
Basal Area ◽  
Abundant Species ◽  
Forest Edge ◽  
Structural Composition ◽  
Forest Interior ◽  
Contrasting Habitats ◽  
Brachystegia Spiciformis

A survey to determine the variation in species and structural composition of trees along the edge-interior gradient was done in the Kilengwe forest in Morogoro region, Tanzania. The forest was categorized into three habitats, namely, edge (0–100 m), intermediate (100–200 m), and interior (>200 m) depending on the distance from the forest margin. A total of six plots of 0.04 ha each were randomly placed in each of the habitats whereby all trees with DBH ≥ 10 cm were inventoried. A total of 67 species representing 26 families were recorded. Fabaceae was the most speciose and abundant family. Brachystegia spiciformis was the most abundant species. Of the recorded species, 10.45% were common in the three habitats while 8.95%, 13.43%, and 26.86% occurred exclusively to the edge, intermediate, and interior habitats, respectively. The forest interior was significantly rich in terms of species richness, diversity, density, and basal area than the edge and intermediate habitats. The edge had significantly higher number of stumps/ha. In summary, the results suggest that edge/intermediate and interior are contrasting habitats in terms of tree species richness, diversity, and structural composition. Moreover, the forest edge and intermediate habitats were found to be characterized by high anthropogenic activities compared to the forest interior habitat.

scholarly journals Dynamics and Edge Effect of an Atlantic Forest Fragment in Brazil

2016 ◽  
Vol 23 (3) ◽  
pp. 340-349 ◽  
Author(s):  
Poliana Gabriella Araújo Mendes ◽  
Maria Amanda Menezes Silva ◽  
Tassiane Novacosque Feitosa Guerra ◽  
Ana Carolina Borges Lins-e-Silva ◽  
Airton de Deus Cysneiros Cavalcanti ◽  
...  
Keyword(s):  
Species Richness ◽  
Atlantic Forest ◽  
Edge Effect ◽  
Woody Plants ◽  
Response Times ◽  
Forest Edge ◽  
Northeastern Brazil ◽  
Forest Fragment ◽  
Canopy Tree ◽  
Forest Interior

ABSTRACT The woody plants in an edge area formed approximately 35 years ago in an Atlantic Forest fragment in northeastern Brazil were examined, and three environments defined: edge, intermediate, and interior. Canopy tree densities and basal areas were found to be similar in all three environments, and also similar to previous published studies in the same region; species richness was greatest at the forest edge. The understory showed greater species richness in the forest interior, but greater diversity and equitability in the intermediate environment. Understory environments close to the forest edge demonstrated larger stem diameters than in the forest interior, although at lesser densities and with smaller total basal areas. Our results indicated the existence of distinct patterns in canopy and understory that most likely reflect differences in the response times of these two vegetation layers, with the understory being more sensitive to alterations in environmental structure.

scholarly journals Forest edge in the Brazilian Atlantic forest: drastic changes in tree species assemblages

Oryx ◽  
2004 ◽  
Vol 38 (4) ◽  
pp. 389-394 ◽  
Author(s):  
Marcondes A. Oliveira ◽  
Alexandre S. Grillo ◽  
Marcelo Tabarelli
Keyword(s):  
Atlantic Forest ◽  
Tree Species ◽  
Current System ◽  
Forest Edge ◽  
Species Assemblages ◽  
Brazilian Atlantic Forest ◽  
Forest Fragment ◽  
Forest Interior ◽  
The Mean ◽  
Threatened Tree Species

In this study we surveyed all trees ≥10 cm diameter at breast height within 20 0.1 ha plots in a 3,500 ha forest fragment, surrounded by sugar cane fields, of the Brazilian Atlantic forest to compare tree species assemblages at the forest edge (0–100 m into forest) vs forest interior (>200 m). Plots were perpendicular to the margin. The mean number of tree species was significantly higher in the forest interior (35.4 ± SD 7.1 vs 18.4 ± SD 4.4). In addition, forest edge differed from interior in the proportion of shade-tolerant, emergent, large/very large-fruited species, and large-seeded tree species. Among the 134 tree species recorded, 24% were exclusive to the forest edge and 57% to the forest interior. Our results suggest that both the current system of protected areas and archipelagos of small fragments (1) tend to retain only a subset of the original flora, (2) will converge in terms of floristic and ecological composition (biotic simplification and homogenization), and (3) will lose rare and threatened tree species.

Gap-phase regeneration in selectively logged lowland swamp forest, northeastern Costa Rica

1998 ◽  
Vol 14 (2) ◽  
pp. 247-260 ◽  
Author(s):  
EDWARD L. WEBB
Keyword(s):  
Costa Rica ◽  
Tree Species ◽  
Structural Damage ◽  
Basal Area ◽  
Abundant Species ◽  
Selective Logging ◽  
Stem Density ◽  
Swamp Forest ◽  
Gap Phase ◽  
Multiple Tree

For sustainable logging to be achieved in tropical forests, there must be successful gap-phase regeneration to restock the logged-over area. This study examined three aspects of gap-phase regeneration in selectively logged lowland swamp forest of northeast Costa Rica. First, logging gaps were censused immediately after extraction to determine the density of advanced regeneration. Stem density and basal area of residual trees ≥ 10 cm dbh in logging gaps was >85% lower than undisturbed forest, and all trees in gaps had sustained structural damage. The common canopy species Pentaclethra macroloba (Fabaceae) was the most abundant species in gaps whereas the timber tree Carapa nicaraguensis (Meliaceae) was absent from all censused gaps. This suggests that canopy replacement, particularly by Carapa, will depend on trees <10 cm dbh or by seed input into logging gaps. Second, the diversity of the understorey was compared with 6-y old single-tree and multiple-tree logging gaps. Multiple-tree logging gaps were the most diverse, but dominated by two ruderal species; however many shade-tolerant species were present in those gaps. This indicates that controlled selective logging can result in a localized shift in species composition, but that logging gaps should return to pre-logging composition with time under a carefully implemented, controlled harvesting regime. Finally, this study found a significant effect of a fringing Carapa tree on logging gap seedling density. Thus, seed arrival into gaps is a barrier to logging gap regeneration, particularly for a large-seeded tree species. Gap-phase regeneration by a large-seeded tree species in managed forest would benefit from seed broadcasting into gaps.

Structure of mixed pine and hardwood stands 12 years after various methods and intensities of site preparation in the Georgia Piedmont

1996 ◽  
Vol 26 (8) ◽  
pp. 1490-1500 ◽  
Author(s):  
Timothy B. Harrington ◽  
M. Boyd Edwards
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Low Cost ◽  
Basal Area ◽  
Diversity Indices ◽  
Site Preparation ◽  
Clear Cut ◽  
Clear Cutting ◽  
Georgia Piedmont ◽  
Compensatory Effect

In the Georgia Piedmont (U.S.A.), size, abundance, and species diversity of trees were quantified in a plantation of Pinustaeda L. 12 years after various methods and intensities of site preparation. In clear-cut only versus site-prepared plots, greater hardwood abundance (27% vs. 8% of the total basal area) and size (8.6 vs. 7.4 m in height) were associated with reduced pine volume (73 vs. 123 m3/ha) and increased Simpson and Shannon diversity indices. Tree-species richness was greater in plots where residual trees from clear-cutting had been removed with a chainsaw versus large machinery (10 vs. 7 species). With increasing site-preparation intensity, reductions in basal area of volunteer pines coincided with proportionate increases (R2 = 0.80) in basal area of planted pines. As a result of this compensatory effect, total volume of all pines varied little (122–134 m3/ha) among site-preparation intensities. Research results suggest that site-preparation treatments can be selected to facilitate the development of a variety of stand structures, including those that favor evenness (clear-cut only) or richness (manual cutting) of tree species, low-cost production of pine fiber (manual cutting), and stand uniformity for management of pine sawtimber (mechanical and herbicide).

Secondary forest succession in a tropical dry forest: patterns of development across a 50-year chronosequence in lowland Bolivia

2002 ◽  
Vol 18 (1) ◽  
pp. 53-66 ◽  
Author(s):  
DEBORAH K. KENNARD
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Stand Structure ◽  
Secondary Forest ◽  
Tropical Dry Forest ◽  
Basal Area ◽  
Forest Stand ◽  
Dry Forest ◽  
Stem Density ◽  
Mature Forest

Stand structure, species richness and population structures of tree species were characterized in 12 stands representing 50 y of succession following slash-and-burn agriculture in a tropical dry forest in lowland Bolivia. Estimates of tree species richness, canopy cover and basal area reached or surpassed 75% of mature forest levels in the 5-, 8-, and 23-y-old stands respectively. Total stem density of the 50-y-old stand was almost twice that of the mature forest stand. This rapid recovery may be due to a high percentage of sprouting tree species, potentially high seed fall into abandoned fields, or the disturbance history of the mature stand. The even-aged size-class structures, dominance of long-lived pioneers, and presence of charcoal and pottery shards in soils of the mature forest stand suggest it formed after a severe disturbance, possibly fire of anthropogenic origin.

Diversity and host tree preferences of vascular epiphytes and vines in a temperate rainforest in southern Chile

2003 ◽  
Vol 51 (4) ◽  
pp. 381 ◽  
Author(s):  
Alejandro A. Muñoz ◽  
Paulina Chacón ◽  
Fernanda Pérez ◽  
Elizabeth S. Barnert ◽  
Juan J. Armesto
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Floristic Composition ◽  
Abundant Species ◽  
Tree Size ◽  
Host Tree ◽  
Southern Chile ◽  
Frequency Distributions ◽  
Trunk Diameter ◽  
Vascular Epiphytes

Vines and epiphytes contribute importantly to the biodiversity of temperate rainforests of southern South America. However, compared with their tropical counterparts, these functional groups have received less attention. We evaluated diversity, floristic composition and relative abundance of vascular epiphytes and vines within a humid temperate forest in northern Chiloé Island, southern Chile. We assessed whether epiphyte and vine species exhibit preferences among host tree species and tested whether species richness on tree hosts differs from that expected by chance, by comparing observed frequencies of occurrence (FO) and species richness with randomly simulated frequency distributions generated under the assumption of no epiphyte preferences. Finally, we tested for associations of epiphyte and vine species with host tree size (trunk diameter at breast height). Eleven species of ferns and nine angiosperms (seven vines, one epiphytic angiosperm and one shrub) were recorded growing epiphytically in a sample of 499 trees. The most abundant species were three vines, Luzuriaga polyphylla (Hook.) Macbr., Griselinia racemosa (Phil.) Taub. and Mitraria coccinea Cav., and five species of filmy ferns (Hymenophyllaceae). Most epiphytes and vines (65%) showed preference for one or two tree species, with seven species being overrepresented on Podocarpus nubigena Lindl. hosts and 10 underrepresented on Drimys winteri J.R. et G.Forster. Epiphyte and vine species richness was significantly lower than expected by chance on D. winteri and higher than expected on Nothofagus nitida (Phil.) Krasser. Three epiphytic ferns showed preferences for large-sized trees, while frequency of occurrence of three common vines was independent of host tree size.

scholarly journals Spider assemblages on tree trunks in primeval deciduous forests of the Białowieża National Park in eastern Poland

2018 ◽  
Vol 29 (2) ◽  
pp. 75-85
Author(s):  
Marzena Stańska ◽  
Tomasz Stański ◽  
Joanna Hawryluk
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
National Park ◽  
Riparian Forest ◽  
Abundant Species ◽  
Deciduous Forests ◽  
Forest Types ◽  
Numerous Species ◽  
Białowieża National Park ◽  
Spider Abundance

We analysed spider assemblages of tree trunks in an oak-lime-hornbeam forest, an ash-alder riparian forest and an alder carr in the primeval stands of the Białowieża National Park. Spiders were collected from June 1998 to October 2000 using bark traps. A total of 2,182 spider individuals, belonging to 43 species and 14 families was collected. The forest types differed in the spider abundance and species richness. The differences probably resulted from different tree species and different environmental conditions in the forest types. The most numerous species in oak-lime-hornbeam forest and in alder carr was Amaurobius fenestralis, whereas Anyphaena accentuatawas the most abundant species in ash-alder riparian forest. Four species (Amaurobius fenestralis, Anyphaena accentuata, Segestria senoculataand Neriene montana) were collected in each month (March – October), whereas most species were recorded sporadically or in some periods.

scholarly journals Stand Structure, Regeneration Status and Distribution Patterns of Six Important Tree Species along Altitudinal Gradients at the Kilum-Ijim Forest Reserve, Cameroon

2020 ◽  
pp. 41-57
Author(s):  
Franklin Bantar Nworo ◽  
Njoh Roland Ndah ◽  
Egbe Enow Andrew
Keyword(s):  
Tree Species ◽  
Stand Structure ◽  
Anthropogenic Activities ◽  
Elevation Gradient ◽  
Basal Area ◽  
Tree Height ◽  
Distribution Patterns ◽  
Forest Reserve ◽  
Altitudinal Gradients ◽  
Regeneration Status

Tropical montane forests are considered to be one of the most species diverse ecosystems. These areas pose specific edaphic and environmental characteristics which enable these areas to harbour wide varieties of organisms. Some of these organisms are threatened and others are endemic to the area. The quest for food and other resources has resulted to indiscriminate exploitation of these montane forest. This study aimed to investigate the stand structure, distribution patterns and regeneration status of six tree species (Nuxia congesta, Pittosporum mannii, Podocarpu slatifolius, Prunus africana, Schefflera abyssinica and Syzygium guineense) along altitudinal gradients in the Kilum-Ijim Forest Reserve, Cameroon. A total of six study plots of one hectare (100 x100 m) each were laid across a 120 m elevation gradient. Two plots were established at each altitudinal gradient with elevations 2377 m, 2437 m and 2497 m. Measurements were taken for tree height, diameter at breast height (DBH 1.3 m) for the tree and poles. The digital Vernier callipers were used to measure collar diameters of seedlings and saplings. The highest tree density of 385 stems/ha was recorded for N. congesta at altitude 2497 m while the least was 20 stems/ha for S. abyssinica at altitude 2377m. The highest seedling density was 1563 stems/ha recorded for P. mannii at altitude 2377m and the least was noted for S. abyssinica at all the three altitudinal gradients.  Nuxia congesta had the highest basal area of 8809.23m2/ha at altitude 2437 m and the least of 74.82m2/ha for P. latifolius at altitude 2437 m.  The highest IVI occurred in N. congesta (131.91) was recorded at altitude 2377 m and the least (24.91) occurred in P. latifolius at altitude 2437 m. The spatial distributions of studied tree species were generally clumped and irregular. The regenerations of species were generally poor, though fair regenerations were noticed for N. congesta and P. mannii. The results showed that the six tree species were highly disturbed by anthropogenic activities. It is therefore imperative to develop and implement effective conservation measures to sustain the biodiversity of this reserve.

Does the abundance of dominant trees affect diversity of a widespread tropical woodland ecosystem in Tanzania?

2015 ◽  
Vol 31 (4) ◽  
pp. 345-359 ◽  
Author(s):  
Deo D. Shirima ◽  
Ørjan Totland ◽  
Pantaleo K. T. Munishi ◽  
Stein R. Moe
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Tree Species ◽  
Woody Species ◽  
Climatic Conditions ◽  
Miombo Woodlands ◽  
Small Individual ◽  
Tree Species Richness ◽  
Wide Range ◽  
Brachystegia Spiciformis

Abstract:Dominant woody species can determine the structure and composition of a plant community by affecting environmental conditions experienced by other species. We explored how dominant tree species affect the tree species richness, diversity, evenness and vertical structural heterogeneity of non-dominant species in wet and dry miombo woodlands of Tanzania. We sampled 146 plots from eight districts with miombo woodlands, covering a wide range of topographic and climatic conditions. We recorded 217 woody plant species belonging to 48 families and 122 genera. Regression analysis showed significant negative linear associations between tree species richness, relative species profile index of the non-dominant and the relative abundance of the dominant tree species (Brachystegia spiciformis and Brachystegia microphylla in wet, and Brachystegia spiciformis and Julbernardia globiflora in dry miombo woodlands). Shannon diversity and evenness had strong non-linear negative relationships with relative abundance of dominant tree species. A large number of small individual stems from dominant and non-dominant tree species suggesting good regeneration conditions, and intensive competition affecting survival. We suggest that dominant miombo tree species are suppressing the non-dominant miombo tree species, especially in areas with high recruitments, perhaps because of their important adaptive features (extensive root systems and ectomycorrhizal associations), which enhance their ability to access limited nutrients.

scholarly journals Tree Species Diversity and Population Structure in the Tropical Forests of North Central Eastern Ghats, India

2014 ◽  
Vol 6 (4) ◽  
pp. 448-453 ◽  
Author(s):  
Dumpa PREMAVANI ◽  
Maradana TARAKESWARA NAIDU ◽  
Malleboyina VENKAIAH
Keyword(s):  
Population Structure ◽  
Species Richness ◽  
Species Diversity ◽  
Tropical Forests ◽  
Tree Species ◽  
Basal Area ◽  
Eastern Ghats ◽  
Tree Species Diversity ◽  
North Central ◽  
Central Eastern

The tree species diversity and population structure were studied in four stands of the tropical forests in the north-central Eastern Ghats, based on tree inventories conducted on four 1-ha plots. In the four independent plots, two 5 x 1000 m transects were established and all trees with ≥ 15 cm girth at breast height were enumerated. The density, frequency, basal area and IVI along with diversity indices viz. Shannon index, species richness, equitability and species dominance were computed to see the variation in tree community. A total of 92 species representing 73 genera under 40 families of angiosperms were recorded. Tree species richness was as low as 34 species per hectare plot in Geddapalli to as high as 48 species in Koruturu. Tree density ranged from 360 stems per hectare in plot Geddapalli to 526 stems in plot Chintapalli and that of total basal area from 16.31 m2 ha-1 in Koruturu to 31.15 m2 ha-1 in Chintapalli. The number of species and stems decreased from the smaller to the largest girth classes. The tree inventories of the study area when compared to those of the other tropical forests showed great differences in density and basal area. This may probably be due to differences in geography and annual rainfall patterns. The information on tree species structure and function can provide baseline information for conservation of the biodiversity.

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