scholarly journals Canopy gaps promote selective stem-cutting by small mammals of two dominant tree species in an African lowland forest: the importance of seedling chemistry

2015 ◽  
Vol 32 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Julian M. Norghauer ◽  
Gregory Röder ◽  
Gaëtan Glauser
Keyword(s):  
Small Mammals ◽  
Tree Species ◽  
Species Difference ◽  
Basal Area ◽  
Tree Regeneration ◽  
Stem Cutting ◽  
Canopy Openness ◽  
Stem Density ◽  
Lowland Forest ◽  
Adult Trees

Abstract:Small mammals can impede tree regeneration by injuring seedlings and saplings in several ways. One fatal way is by severing their stems, but apparently this type of predation is not well-studied in tropical rain forest. Here, we report on the incidence of ‘stem-cutting’ to new, wild seedlings of two locally dominant, canopy tree species monitored in 40 paired forest understorey and gap-habitat areas in Korup, Cameroon following a 2007 masting event. In gap areas, which are required for the upward growth and sapling recruitment of both species, 137 seedlings of the long-lived, light-demanding, fast-growing large tropical tree (Microberlinia bisulcata) were highly susceptible to stem-cutting (83% of deaths) — it killed 39% of all seedlings over a c. 2-y period. In stark contrast, seedlings of the more shade-tolerant, slower-growing tree species (Tetraberlinia bifoliolata) were hardly attacked (4.3%). In the understorey, however, stem-cutting was virtually absent. Across the gap areas, the incidence of stem-cutting of M. bisulcata seedlings showed significant spatial variation that could not be explained significantly by either canopy openness or Janzen–Connell type effects (proximity and basal area of conspecific adult trees). To examine physical and chemical traits that might explain the species difference to being cut, bark and wood tissues were collected from a separate sample of seedlings in gaps (i.e. not monitored for stem-cutting). These analyses suggested that, compared with T. bifoliolata, the lower stem density, higher Mg and K and fatty acid concentrations in bark, and fewer phenolic and terpene compounds in M. bisulcata seedlings made them more palatable and attractive to small-mammal predators, likely rodents. We conclude that selective stem-cutting is a potent countervailing force to the current local canopy dominance of the grove-forming M. bisulcata by limiting the recruitment and abundance of its saplings. Given the ubiquity of gaps and ground-dwelling rodents in pantropical forests, it would be surprising if this form of lethal browsing was restricted to Korup.

scholarly journals Tree Species Composition and Natural Regeneration Status of Southeast Region of Bangladesh

2020 ◽  
Vol 5 (1) ◽  
pp. 27
Author(s):  
Abir Dey ◽  
Aklima Akther
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Natural Regeneration ◽  
Native Species ◽  
Basal Area ◽  
Conservation Strategies ◽  
Stem Density ◽  
Importance Value Index ◽  
Tree Species Composition ◽  
Large Trees

The study aimed to quantify and discuss the current condition of the tree species composition and natural regeneration of southeast parts of Bangladesh (Cox’s Bazar North Forest Division). A total of 121 stems having dbh ≥10cm and 3481 stems of regenerating tree species (dbh <10cm) per hectare were recorded. A large trees comprised of 17 species belonging to 10 families and 14 genera and 30 regenerating tree species belonging to 19 families and 27 genera have been found. The forests were highly non-uniform, with three or four species represented most of the stands. The values of diversity indices indicated limited plant diversity, which is dominated by two or three tree species. Stems of 10-30 cm dbh contributed almost 90% of the total stem density, whereas more than 80% of the total basal area still belonged to trees with dbh 100 cm or above. Dipterocarpus turbinatus was the most dominant species which have the highest Importance Value Index (IVI) with 135.82 and embodied 37.71% of the total stand density and 72.19% of total basal area. The study will provide scientific basis for the future implementation of forest conservation strategies in tropical forests of Southeast Asia, particularly in Bangladesh. This study may also pave the way to further research on regeneration potentials of the native species for conservation and enhancement of forests in future.

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.

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.

scholarly journals Phytosociological observations on tree species diversity of an urban tropical dry deciduous forest of central India

2020 ◽  
Vol 7 (3) ◽  
pp. 1029-1138
Author(s):  
Dharmendra Dugaya ◽  
PV Kiran ◽  
Rajnish Kumar Singh ◽  
Manmeet Kaur ◽  
Pradeep Chaudhry
Keyword(s):  
Tree Species ◽  
Deciduous Forest ◽  
Forest Type ◽  
Basal Area ◽  
Central India ◽  
Capital City ◽  
Stem Density ◽  
Importance Value Index ◽  
Tree Community ◽  
Dry Deciduous Forest

We analyzed phytosociological characteristics of a tropical dry deciduous forest located in an urban environment of Indian Institute of Forest Management (IIFM) Campus in the capital city of Bhopal of Madhya Pradesh state, Central India. A Comparison has been made among the tree community characteristics during the years 1988, 2002 and 2020 in terms of tree species composition, stem density, basal area and Importance Value Index (IVI). At the time of establishment of the institute in 1988, the forest area resembleda degraded dry scrubland. Due to continuous care/protection, plantation activities, degraded forest recovered remarkably, ecological processes evolved favorably with canopy cover reaching over 60% in some patches and about 50% in general over most part of the campus. During last two decades, tree density increased from 319 to 525 stem ha-1 indicating an increase of 64% whereas basal area increased from 18470.79 cm2 ha-1 to 29782.31 cm2 ha-1,an increase of about 61%. Leguminaceae family represented 26.4% of the tree community followed by Combretaceae (11.76%). Shannon-Weiner index (1.31), Simpson index (0.93) and evenness index (0.85) are within the reported ranges for similar forest type of dry deciduous nature in India. Theresults of the presentstudy will help forest managers in conservation planning of urban tropical forest ecosystem of central India.

scholarly journals COMMUNITY STRUCTURE AND REGENERATION STATUS OF TREE SPECIES IN KYONGNOSLA ALPINE SANCTUARY, EASTERN HIMALAYA, INDIA

2021 ◽  
Vol 8 (2) ◽  
pp. 241-257
Author(s):  
Subhajit Lahiri ◽  
Sudhansu Sekhar Dash
Keyword(s):  
Tree Species ◽  
Mixed Forest ◽  
Basal Area ◽  
Habitat Destruction ◽  
Eastern Himalaya ◽  
Diameter Distribution ◽  
Mature Trees ◽  
Regeneration Status ◽  
Adult Trees ◽  
Over Exploitation

Habitat destruction, over exploitation, monoculture are major reasons for loss of primary forests in Himalaya. Tree population, composition and diversity particularly in the temperate Himalaya play a key role in the maintenance of many ecosystem services and natural biogeochemical cycles. The present study explores composition and regeneration status of tree species in a temperate mixed forest in Kyongnosla Alpine Sanctuary, East Sikkim, India.  Two sites at an elevation range of 2800–3800 m were selected and 20 plots of 20 m × 20 m for trees, 80 plots of 5 m × 5 m for saplings, and 160 plots of 1 m × 1 m for seedlings were sampled to study the regeneration status. A total of 17 tree species belonging to 9 genera and 8 families were recorded of which Rhododendron was the most dominant genus with maximum number of species. All the phytosociological attributes, such as relative density, abundance and important value index were calculated. The average species richness of adult trees and saplings was 13.5± 0.7 and for seedlings it was 12.5 ± 0.07. The mean density of seedlings was 3609.77 ± 494.39 individuals/ ha, for saplings  1540 ± 113.13 individuals/ha and of mature trees  548.75 ± 8.83 individuals/ha. Total basal area cover ranged from 36.61 to 40.35 m2/ha for trees, from 1.54 to 1.71 m2/ha for saplings.  Fair regeneration was observed in 64.72% of total species; good regeneration observed in 17.64% species, 11.76 % species exhibited poor regeneration while 5.88% showed no regeneration.  Density-diameter distribution exhibited decrease in tree densities towards higher DBH classes. The study not only provides reliable information on the ecosystem’s health of the sanctuary but also will help in understanding the complexity of the ecosystem function and an approach to conservation of biota.

scholarly journals Analyzing long-term impacts of ungulate herbivory on forest-recruitment dynamics at community and species level contrasting tree densities versus maximum heights

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ursula Nopp-Mayr ◽  
Susanne Reimoser ◽  
Friedrich Reimoser ◽  
Frederik Sachser ◽  
Leopold Obermair ◽  
...  
Keyword(s):  
Tree Species ◽  
Life Stage ◽  
Tree Regeneration ◽  
Species Level ◽  
Ecosystem Dynamics ◽  
Stem Density ◽  
Maximum Height ◽  
Ungulate Herbivory ◽  
Over Time

AbstractHerbivores are constitutive elements of most terrestrial ecosystems. Understanding effects of herbivory on ecosystem dynamics is thus a major, albeit challenging task in community ecology. Effects of mammals on plant communities are typically explored by comparing plant densities or diversity in exclosure experiments. This might over-estimate long-term herbivore effects at community levels as early life stage mortality is driven by a multitude of factors. Addressing these challenges, we established a set of 100 pairs of ungulate exclosures and unfenced control plots (25 m2) in mixed montane forests in the Alps in 1989 covering a forest area of 90 km2. Investigations ran until 2013. Analogous to the gap-maker–gap-filler approach, dynamically recording the height of the largest trees per tree species in paired plots with and without exclosures might allow for assessing herbivore impacts on those individuals with a high probability of attaining reproductive stages. We thus tested if recording maximum heights of regenerating trees would better reflect effects of ungulate herbivory on long-term dynamics of tree regeneration than recording of stem density, and if species dominance patterns would shift over time. For quantifying the effects of ungulate herbivory simultaneously at community and species level we used principle response curves (PRC). PRCs yielded traceable results both at community and species level. Trajectories of maximum heights yielded significant results contrary to trajectories of total stem density. Response patterns of tree species were not uniform over time: e.g., both Norway spruce and European larch switched in their response to fencing. Fencing explained about 3% of the variance of maximum tree heights after nine years but increased to about 10% after 24 years thus confirming the importance of long-term surveys. Maximum height dynamics of tree species, addressed in our study, can thus reflect local dominance of tree species via asymmetric plant competition. Such effects, both within and among forest patches, can accrue over time shaping forest structure and composition.

scholarly journals Composition and structure of a lowland forest in the core zone of the Bukit Duabelas National Park, Jambi, Indonesia

2021 ◽  
Vol 2 (1) ◽  
pp. 12-24
Author(s):  
Azwar Anas ◽  
Kuswata Kartawinata ◽  
Nisyawati Nisyawati
Keyword(s):  
Tree Species ◽  
National Park ◽  
Basal Area ◽  
Lowland Forest ◽  
Core Zone ◽  
New Information ◽  
Composition And Structure ◽  
High Conservation ◽  
Conservation Values ◽  
Shorea Leprosula

The objective of the study was to obtain data on composition and structure of the forest in the midsection of the Bukit Duabelas National Park core zone, designed to complement the existing data and  provide new information  potentials for the management of the park  core zone. The study was carried out in October-November 2012. Observations were made on plots of one hectare (100 m x 100 m), which was divided into 100 subplot, measuring 10 m x 10 m each. Enumeration  of tree species with  diameters ≥ 10 cm revealed that as many as 540 individuals were recorded, consisting of 89 species and 36 families, with a total  basal area of 30.837 m2 and  only three species of Dipterocarpaceae were registered. The forest had a low diversity as indicated by low species richness, much lower than in the  undisturbed lowland  primary forests in the Batang Gadis National Park in North Sumatra, where similarity was very low (5.9 %).  The forest in the plot was designated as the  Dacryodes rostrata- Shorea leprosula Association,  named after two species with highest importance values, thus the dominant. The structure and species composition pointed to the regenerating  forest after heavy disturbances.  The forest has been  undergoing  slow natural succession,  leading to  the formation of the forest similar to the original climax forest. Natural recovery through succession could be enhanced and assisted by means of ecological restoration, through planting of tree species characteristics of forests in Jambi, including  species of Dipterocapaceae, useful species having values to maintain the livelihood of the indigenous native tribe Suku Anak Dalam  and rare, endemic other species having  high conservation values. Tujuan studi  ini adalah  untuk memperoleh data tentang komposisi dan struktur hutan di bagian tengah zona inti Taman Nasional Bukit Duabelas. Studi   dirancang untuk melengkapi data yang telah ada dan untuk menyajikan informasi baru yang berpotensi untuk digunakan dalam pengelolaan zona inti taman nasional. Penelitian dilaksanakan pada bulan Oktober-November 2012 dalam petak seluas satu hektare (100 m x 100 m), yang dibagi menjadi 100 anak-petak dengan ukuran masing-masing 10 m x 10 m.   Pencacahan pohon dengan diameter ≥ 10 cm  menghasilkan 540 batang, yang terdiri atas 89 jenis dan 36 suku, dengan luas bidang dasar total 30.837 m2 dan hanya tercatat  tiga jenis Dipterocarpaceae. Keanekaragaman jenis hutan rendah,  seperti  ditunjukan oleh  rendahnya kekayaan jenis, jauh lebih rendah dibandingkan dengan  hutan primer yang tidak terganggu di Taman Nasional Batang Gadis di Sumatra Utara, yang mempunyai  kesamaan hanya 5,9 % dengan Taman Nasional Bukit Duabelas.  Berdasarkan dua jenis dominan dengan nilai kepentingan tinggi, komunitas pohon dalam petak dinamakan Asosiasi Dacryodes rostrata- Shorea leprosula. Struktur dan komposisi jenis menunjukan status hutan sebagai hutan yang sedang beregenerasi setelah mengalami gangguan. Hutan sedang mengalami suksesi alami yang lambat menuju ke pembentukan hutan yang serupa dengan hutan klimaks aslinya. Pemulihan alami melalui suksesi dapat dipercepat dan dibantu dengan restorasi ekologi melalui penanaman jenis-jenis khas hutan alami Jambi, termasuk  Dipterocapaceae, jenis-jenis bermanfaat dan mempunyai nilai untuk keberlanjutan kehidupan dan kesejahteraan masyarakat asli Suku Anak Dalam dan jenis-jenis langka, endemik dan jenis lain yang mempunyai nilai konservasi tinggi.

scholarly journals Tree Diversity and Community Composition of the Tutong White Sands, Brunei Darussalam: A Rare Tropical Heath Forest Ecosystem

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hazimah Din ◽  
Faizah Metali ◽  
Rahayu Sukmaria Sukri
Keyword(s):  
Community Composition ◽  
Forest Ecosystem ◽  
Tree Species ◽  
Basal Area ◽  
Iucn Red List ◽  
Stem Diameter ◽  
Canopy Openness ◽  
Total N ◽  
Brunei Darussalam ◽  
White Sands

Bornean heath (Kerangas) forests are a unique and increasingly rare tropical forest ecosystem that remains little studied. We quantified tree floristic diversity inKerangasforests in the Tutong White Sands, Brunei Darussalam, and investigated the influence of soil and environmental variables on community composition. Six 20 m × 20 m plots were established, where all trees of ≥5 cm diameter at breast height (DBH) were identified and measured to determine stem diameter and basal area. We determined pH, gravimetric water content, and concentrations of total nitrogen (N) and phosphorus (P) in topsoil, as well as litter depth and percentage canopy openness. A total of 296 trees were recorded, representing 78 species in 59 genera and 38 families. Stem diameter, basal area, species richness, and species diversity differed significantly among the six plots. The NMDS ordination revealed that differences in tree community compositions were significantly associated with total N concentrations and percentage canopy openness. Despite the small sampling area, we recorded several Bornean endemic tree species (16/78 tree species; 20.5%), including several IUCN Red List endangered and vulnerable species. Our results illustrate the potentially high conservation value of theKerangasforests in the Tutong White Sands and highlight the urgent need to protect and conserve this area.

Vegetation community monitoring at Lincoln Boyhood National Memorial: 2011–2019

2021 ◽  
Author(s):  
Sherry Leis
Keyword(s):  
Tree Species ◽  
Sugar Maple ◽  
Basal Area ◽  
Ground Cover ◽  
Tree Regeneration ◽  
Tree Planting ◽  
Percent Cover ◽  
Observer Error ◽  
Ground Flora ◽  
Overstory Trees

Lincoln Boyhood National Memorial celebrates the lives of the Lincoln family including the final resting place of Abraham’s mother, Nancy Hanks Lincoln. Lincoln’s childhood in Indiana was a formative time in the life our 16th president. When the Lincoln family arrived in Indiana, the property was covered in the oak-hickory forest type. They cleared land to create their homestead and farm. Later, designers of the memorial felt that it was important to restore woodlands to the site. The woodlands would help visitors visualize the challenges the Lincoln family faced in establishing and maintaining their homestead. Some stands of woodland may have remained, but significant restoration efforts included extensive tree planting. The Heartland Inventory and Monitoring Network began monitoring the woodland in 2011 with repeat visits every four years. These monitoring efforts provide a window into the composition and structure of the wood-lands. We measure both overstory trees and the ground flora within four permanently located plots. At these permanent plots, we record each species, foliar cover estimates of ground flora, diameter at breast height of midstory and overstory trees, and tree regeneration frequency (tree seedlings and saplings). The forest species composition was relatively consistent over the three monitoring events. Climatic conditions measured by the Palmer Drought Severity Index indicated mild to wet conditions over the monitoring record. Canopy closure continued to indicate a forest structure with a closed canopy. Large trees (>45 cm DBH) comprised the greatest amount of tree basal area. Sugar maple was observed to have the greatest basal area and density of the 23 tree species observed. The oaks characteristic of the early woodlands were present, but less dominant. Although one hickory species was present, it was in very low abundance. Of the 17 tree species recorded in the regeneration layer, three species were most abundant through time: sugar maple (Acer saccharum), red bud (Cercis canadensis), and ash (Fraxinus sp.). Ash recruitment seemed to increase over prior years and maple saplings transitioned to larger size classes. Ground flora diversity was similar through time, but alpha and gamma diversity were slightly greater in 2019. Percent cover by plant guild varied through time with native woody plants and forbs having the greatest abundance. Nonnative plants were also an important part of the ground flora composition. Common periwinkle (Vinca minor) and Japanese honeysuckle (Lonicera japonica) continued to be the most abundant nonnative species, but these two species were less abundant in 2019 than 2011. Unvegetated ground cover was high (mean = 95%) and increased by 17% since 2011. Bare ground increased from less than 1% in 2011 to 9% in 2019, but other ground cover elements were similar to prior years. In 2019, we quantified observer error by double sampling two plots within three of the monitoring sites. We found total pseudoturnover to be about 29% (i.e., 29% of the species records differed between observers due to observer error). This 29% pseudoturnover rate was almost 50% greater than our goal of 20% pseudoturnover. The majority of the error was attributed to observers overlooking species. Plot frame relocation error likely contributed as well but we were unable to separate it from overlooking error with our design.

scholarly journals Successional age and forest structure in a Costa Rican upper montane Quercus forest

1996 ◽  
Vol 12 (5) ◽  
pp. 681-698 ◽  
Author(s):  
Maarten Kappelle ◽  
Thorwald Geuze ◽  
Miguel E. Leal ◽  
Antoine M. Cleef
Keyword(s):  
Tree Species ◽  
Secondary Forest ◽  
Basal Area ◽  
Diversity Indices ◽  
Costa Rican ◽  
Canopy Height ◽  
Primary Forest ◽  
Stem Density ◽  
Neotropical Forests ◽  
Structural Recovery

ABSTRACTChanges in structure of a Costa Rican upper montane Quercus forest were studied in twelve 0.1 ha plots along a chronosequence including 8- to 20-year-old Early Secondary Forest (ESF), 25- to 32-year-old Late Secondary Forest (LSF) and mature Primary Forest (PF). In 1.2 ha 2854 stems ≥ 3.0 cm dbh belonging to 42 tree species were recorded. Tree species richness per 0.1 ha ranged from 15 to 30. Diversity indices did not change significantly during succession. Stem density did not differ significantly among successional phases, while basal area was significantly higher in PF than in ESF and LSF. Maximum canopy height and basal area increased linearly during the first three decades of recovery. Height and dbh showed a significant, logarithmic regression for all forest phases. A period of 84 y was estimated as the theoretically minimum time needed for structural recovery. The maximum canopy height and basal area recovered two to five times slower in upper montane than in lower montane or lowland Neotropical forests.

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