Effects of tree species heterogeneity on leaf fall in primary and logged dipterocarp forest in the Ulu Segama Forest Reserve, Sabah, Malaysia

1994 ◽  
Vol 10 (1) ◽  
pp. 1-26 ◽  
Author(s):  
T. B. A. Burghouts ◽  
E. J. F. Campbell ◽  
P. J. Kolderman

ABSTRACTEffects of tree species heterogeneity on leaf fall were studied in a primary (4 ha) and in a selectively logged forest plot (2.5 ha) in the Ulu Segama Forest Reserve, Sabah, Malaysia, from April 1988 to December 1989. Leaf fall was collected at 30 sampling points in each plot, and identified to species.Dipterocarpaceae, Euphorbiaceae, Lauraceae, Fagaceae and Meliaceae are important tree families in both plots with regard to their contribution to total basal area, tree density and annual leaf fall. The total number of tree species was higher in the primary forest plot (267) than in the logged forest plot (218), although the number of climber species was higher in the logged forest (44) than in the primary forest plot (33). The overlap in species composition between the two forest plots was relatively small (49%) compared with that in family composition (88%).In the primary forest plot, the Dipterocarpaceae contributed 29% of the total basal area and 34% of the annual leaf fall. In the logged forest plot these contributions were much lower, 11% and 15%. The contribution to annual leaf fall made by climbers and pioneer trees was higher in the logged forest plot (34%) than in the primary forest plot (8%).In the primary forest plot, leaf fall was dominated My large emergent and main canopy trees, mainly dipterocarps, and occurred as regular large peaks. In the logged forest leaf fall was dominated by climbers and many, relatively small trees of pioneer species, such as Macaranga hypoleuca, and was more evenly distributed in time.

1987 ◽  
Vol 3 (4) ◽  
pp. 315-330 ◽  
Author(s):  
N. Manokaran ◽  
K. M. Kochummen

ABSTRACTChanges in the lowland dipterocarp forest structure and composition are described for a 34-year period between 1947 and 1981 in Sungei Menyala Forest Reserve, Peninsular Malaysia. Although tree density declined by about 10%, basal area changed little, averaging 32.4 m2 ha−1. Size class distributions in 1947 and 1981 were not significantly different. Mortality rates were independent of size class. Mortality exceeded recruitment during the first 16 years to 1963, but was thereafter almost exactly balanced by recruitment. Recruitment rate increased significantly for the latter part of the study.Mortality was greater than average for understorey species and lower for emergents. Pioneer and late seral species together showed significantly higher mortality rates. Amongst the commoner species, emergent, late-seral and pioneer species showed the highest annual diameter growth rates with species averages over all size classes exceeding 3 mm yr−1; rates for main-canopy species were between 1.5 and 2.5 mm yr−1, and understorey species generally less than 2 mm yr−1.Species richness was almost identical in 1947 and 1981 (243, 244 species), but a clear decline (to 229 species) between 1953 and 1971 was recovered by 1981. Most species showed little net change in density over the 34-year period, but eight of the 32 commoner species showed significant changes, all unidirectional. These changes in species composition are not negligible, but further analysis is needed to determine if, for example, they are related to disturbance of part of the plot in 1917.


1992 ◽  
Vol 335 (1275) ◽  
pp. 407-416 ◽  

A two-year study on leaf litter decomposition and litter invertebrates was carried out in a primary (4 ha ( = 4 x 10 4 m 2 )) and logged dipterocarp forest plot (2.5 ha) in the Danum Valley, Sabah, Malaysia. Annual leaf litterfall, leaf litter layer mass and leaf litter decomposition, measured as leaf litter mass loss, were not significantly different between plots. Spatial variation among the 30 replicate sites within each plot was high. Annual rates of total litterfall, leaf litterfall and leaf litter mass loss were 11.5, 6.6 and 6.4 t ha -1 for the primary forest plot and 11.9, 6.2 and 5.5 t ha -1 for the logged forest plot. Rainfall (3000 mm y -1 ) and litterfall were high throughout the year and rates of litterfall and litter disappearance were not related to the pattern of rainfall. In the primary and logged forest, leaf litter layer mass and annual rates of leaf litter disappearance increased with annual leaf litterfall. In the primary forest, the abundance of litter invertebrates increased with mass of leaf litter and fine roots. This invertebrate abundance was higher in the primary forest with a significantly higher abundance of mites, pseudoscorpions and termites. The proportion of mites and pseudoscorpions of the invertebrate fauna was higher in the primary forest; beetles, millipedes and cockcroaches were higher in the logged forest. The most abundant invertebrates were ants, springtails, spiders, woodlice and mites.


1992 ◽  
Vol 335 (1275) ◽  
pp. 443-457 ◽  

In lowland dipterocarp forest in Sabah, Malaysia, most primary forest bird species were present in areas selectively logged eight years previously. However, certain taxa, notably flycatchers, woodpeckers, trogons and wren-babblers, became comparatively rare. In contrast, nectarivorous and opportunistic frugivorous species were significantly more abundant. Few species appeared to change foraging height, but netting rates suggest that the activity of some species had increased, or that some birds ranged over larger areas after logging. Although there is still much to be learned about the survival of birds in logged forest, large areas of this habitat are important for bird conservation. However, the susceptibility of logged forest to fire, and our present incomplete understanding of bird behaviour and population dynamics in logged forests mean that they should not be considered by conservationists as alternatives to reserves of primary forest.


2017 ◽  
Vol 40 (1) ◽  
pp. 1-8
Author(s):  
Bhawna Adhikari ◽  
◽  
Bhawana Kapkoti ◽  
Neelu Lodhiyal ◽  
L.S. Lodhiyal ◽  
...  

Present study was carried out to assess the structure and regeneration of Sal forests in Shiwalik region of Kumaun Himalaya. Vegetation analysis and tree canopy density was determined by using quadrat and densitometer, respectively. Density of seedlings, saplings and trees was 490-14067, 37-1233, and 273-863 ind.ha-1 respectively. The basal area was 0.12-5.44 m2 ha-1 reported for saplings and 25.4-77.6 m2 ha-1 for trees. Regeneration of Sal was found good in Sal mixed dense forest followed by Sal open forest and Sal dense forest, respectively. Regeneration of Sal was assisted by the presence of associated tree species as well as the sufficient sunlight availability on ground due to adequate opening of canopy trees in Sal forest. Thus it is concluded that the density of tree canopy, sunlight availability and also associated tree species impacted the regeneration of Sal in the region.


2019 ◽  
Vol 12 ◽  
pp. 194008291986426
Author(s):  
Akin Akinnagbe ◽  
Oliver Gailing ◽  
Reiner Finkeldey ◽  
Amadu Lawal

Two important West African timber tree species with differing successional status, Mansonia altissima A. Chev and Triplochiton scleroxylon K. Schum were investigated in this study. Triplochiton scleroxylon is a pioneer species found in open forests, whereas Mansonia altissima is a nonpioneer light-demanding tree species occurring in closed forests. Amplified fragment length polymorphism markers were used to compare the genetic diversities of these two timber species in stands with different degrees of human impact (isolated forest patch, logged forest, farmland, plantation, and primary forest). Contrasting effects of human impact on genetic diversity were detected for these two timber species. The results suggested severe effects of human impact on the genetic diversity of Mansonia altissima, a nonpioneer species. However, no adverse effect was recorded in Triplochiton scleroxylon, a pioneer species. These findings indicate that nonpioneer tree species could be more prone to genetic erosion than pioneer tree species as a result of adverse human impacts. Therefore, conservation of genetic diversity in both pioneer and nonpioneer tree species populations would likely necessitate different measures.


1998 ◽  
Vol 14 (3) ◽  
pp. 323-340 ◽  
Author(s):  
D. TORIOLA ◽  
P. CHAREYRE ◽  
A. BUTTLER

Secondary succession in a 19-y old tropical rainforest of French Guiana was investigated through the distribution pattern of primary forest species. The experimental plot of 25 ha was logged to simulate conditions of a paper pulp cut. Enumeration of all plants of height ≥ 50 cm in 52 subplots 10 m × 10 m indicated the number of species and individuals in five species categories; short-lived pioneer species, pioneer species that persist in mature forest, primary forest species capable of germinating in shade, primary forest species that indicate a preference for clearings (small gaps) in mature forest and understorey primary forest species. Change in proportion of the most abundant species (≥ 1 cm dbh) over the last 15 y indicated a decrease in short-lived pioneer species and an increase in pioneers that can persist in the mature forest. Proportion of species categories per height class indicated that primary forest species were mainly found in the lower height class in this forest which is largely dominated by secondary forest tree species forming a canopy that rarely exceeds 20 m. Individuals of primary forest species were encountered on ARBOCEL as sprouts from large stumps, sprouts from juveniles or as untraumatised saplings or juveniles. The distribution pattern in a 4-ha area of 11 selected primary forest canopy tree species revealed an overall trend in recolonisation of this species category in the secondary forest. Considered individually, the clustered distribution of stems of Eperua grandiflora showed the importance of regeneration through sprouting or remaining individuals. The gradient distribution, oriented from the edge to the centre of the studied plot, and displayed by the stem densities of Virola michelii, suggested a recent progressive dispersal of seeds. A more dynamic recolonisation front was observed for the primary forest understorey species Cassipourea guianensis and was probably linked to both the initial logging conditions and the fact that this species fruits when relatively young.


2021 ◽  
Vol 25 (6) ◽  
pp. 921-926
Author(s):  
A.J. Oloketuyi ◽  
O.T. Adeoye ◽  
O.A. Aina-Oduntan ◽  
I.E. Odiaka ◽  
O.S. Afolabi

Effects of forest fire on the regeneration potential of trees at Olokemeji Forest Reserve was established in this study. The Olokemeji fire experimental plot was selected at the reserve. The site was divided into three plots; late fire treatment was applied to Plot A, Early fire treatment was also applied to Plot B and no fire treatment at plot C (Control plot). The diameter at breast height (dbh) and tree height (m) of the tree species in the plots were assessed prior and post fire treatment. The regeneration potential of the selected plots after burning were assessed through the occurrence of saplings and seedlings obtained. The highest basal area (m2) were found in plot C followed by plot B and Plot C with mean value of 0.64, 0.55 and 0.30 m2 respectively. The number of stems per plot ranged from 25 to 67. The regeneration potentials of the three plots were found to be noteworthy. Early and late year fire regime adopted had both positive and negative effect on the regeneration potentials of tree species. This study has established the effect and relevance of fire on forest and wildlife management. It’s therefore recommended in this study that Prescribed or controlled burning should be encouraged as appropriate sivilcultural management tool for stimulating basal area growth, natural regeneration, production of tree species seedlings and saplings.


Author(s):  
Franklin Bantar Nworo ◽  
Njoh Roland Ndah ◽  
Egbe Enow Andrew

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.


2021 ◽  
Vol 2 (1) ◽  
pp. 16-19
Author(s):  
Ibrahim Umar ◽  
Lamido Auwalu ◽  
Ali Zakari ◽  
Ibrahim Fatima ◽  
Yahaya Umar Kubura ◽  
...  

Ecotourism refers to travelling to relatively undisturbed or uncontaminated natural areas, such as protected areas, with the aim of studying, admiring, and enjoying the scenery and the faunal and floral composition along with its existing cultural aspects. This paper evaluated Tree species composition of Maladumba Lake and Forest Reserve, Bauchi-Nigeria for sustainable eco-tourism development. Wandering quarter method of vegetation analysis was employed for the study where five sampling sites were studied to determine species richness, percentage frequency, basal area, relative density, relative dominance, importance value indices, mean distance between trees, mean area of trees and number of individual stem per hectare of tree species encountered. Results obtained indicated total of eighteen different Tree species in the protected area with Mitragyna inermis (126732.9 cm), Adansonia digitata (31714.9 cm), Balanites aegyptiaca (29727.3 cm), and Piliostigma thonningii (28697.7 cm) as species with the highest basal area. While Funtumia elastica presented the highest frequency of occurrence (80%) followed by Acacia nilotica, Anogeissus leiocarpus, Balanites aegyptiaca and Cassia singueeana with 60% each. Relative densities of Mitragyna inermis (18.1%) stood as the highest, followed by Funtumia elastica (16.6%) and Balanites aegyptiaca (12.5%). Relative dominance suggested Mitragyna inermis (18.1%) with the highest value seconded by Adansoni digitata (12.4%) and Balanites aegyptiaca (11.7%). Mitragyna inermis (49.8) had the highest IVI followed by Balanites aegyptiaca (24.4) then Piliostigma thonningii (11.7). Very low values of mean distance between trees (6.9 m), mean area occupied by individual trees (47.6 m), and density of trees per hectare (210) suggested sparsely populated vegetation cover in the protected area. It was concluded that Maladumba Lake and Forest Reserve is under serious deforestation. As an Ecotourism attraction, serious reforestation program was recommended to salvage the situation before the whole protected lose its value.


2014 ◽  
Vol 3 (1) ◽  
pp. 10 ◽  
Author(s):  
Humphrey Igbinosa Aigbe ◽  
Godwin Ejakhe Omokhua

Tree species composition and diversity were assessed in Oban Forest Reserve. Three stage sampling procedure was used to collect data on tree parameters – diameter at breast height (dbh); diameters over bark at the base, middle and top; merchantable height and total height using a minimum dbh limit of ≥10 cm in the tertiary sample plots. A total of 808 trees were measured and 72 species identified in the study area. Stand level parameters were estimated and tree diversity assessed. Results indicate that an average number of stems encountered per hectare were 306. Population densities of individual tree species ranged from 1 to 22 ha-1. Population densities of species were poor. The basal area/ha estimated is 34.67m2 and the species richness index obtained was 10.605, which indicate high species richness. The value of Shannon’s Index (HI) is 3.795 which is quite high.The results show that the forest reserve is a well-stocked tropical rainforest in Nigeria. The relative richness of the forest reserve in terms of individual tree species does not correlate well with the abundance because the abundance of each of the species was quite low and density poor. While there is paucity of most species, Staudtia stipitata was the most abundant (22 tree/ha). The forest has reverted back to the turbulent agrading stage of the forest growth cycle. 


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