Heterospecific Tree Density and Environmental Factors Affect Afzelia africana Sm. Population Structure in the Pendjari Biosphere Reserve, West Africa: Implications for Management and Restoration

Information on how abiotic and biotic factors affect species population structures and regeneration are critical for understanding plant growth in natural habitats. Here, we used the data from three spatially distinct populations of Afzelia africana Sm. in the Pendjari Biosphere Reserve in Benin, to determine how the species population structures respond to abiotic and biotic factors. Afzelia africana population structures were studied using several parameters including basal area, tree height, density of successive diameter classes, and size class slope. We tested for individual effects of abiotic (mound density, soil type, and terrain slope) and biotic (heterospecific tree density) factors on the species population structure. We also tested for similarity of species composition among studied A. africana population stands. Results revealed a tree density structure with mature individuals, and size class distribution indicating a recruitment bottleneck at the juvenile stage (10–20 cm diameter), possibly due to mammal browsing, natural and artificial fires. Heterospecific tree density was positively associated with A. africana adult density but negatively related to the species growth parameters (mean diameter, basal area, and tree height). These results indicate some degrees of niche overlap between A. africana and coexisting species but also partly reflect A. africana tolerance and adaptation to limited resources environment. Soil type significantly influenced both basal area and regeneration density, greater values being observed on silt-sand-rocky soils. Basal area was higher on steeper slope, probably a result of species conservative strategies. These findings were discussed in line with management and restoration action needs in the Pendjari Biosphere Reserve.

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Recruitment, growth and mortality of tree species in a lowland dipterocarp forest in Peninsular Malaysia

Journal of Tropical Ecology ◽

10.1017/s0266467400002303 ◽

1987 ◽

Vol 3 (4) ◽

pp. 315-330 ◽

Cited By ~ 99

Author(s):

N. Manokaran ◽

K. M. Kochummen

Keyword(s):

Basal Area ◽

Mortality Rates ◽

Peninsular Malaysia ◽

Recruitment Rate ◽

Size Class ◽

Tree Density ◽

Pioneer Species ◽

Forest Reserve ◽

Dipterocarp Forest ◽

Lowland Dipterocarp Forest

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.

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Altitudinal zonation of rain forest on Bukit Belalong, Brunei: soils, forest structure and floristics

Journal of Tropical Ecology ◽

10.1017/s0266467400010427 ◽

1997 ◽

Vol 13 (2) ◽

pp. 221-241 ◽

Cited By ~ 37

Author(s):

Colin A. Pendry ◽

John Proctor

Keyword(s):

Rain Forest ◽

Basal Area ◽

Tree Height ◽

Montane Forest ◽

Tree Density ◽

Chemical Analyses ◽

Lowland Rain Forest ◽

Altitudinal Zonation ◽

Maximum Tree Height ◽

Number Of Individuals

ABSTRACTBukit Belalong, Brunei, is a small mountain (913 m) of uniform shale lithology with continuous primary rain forest from its base to its summit. Three 0.25 ha plots were established at each of three altitudes (200, 500 and 850 m) to investigate the altitudinal zonation of the soils and the vegetation. One soil profile from each altitude is described and chemical analyses of the soils indicate that they are similar at all altitudes. In each plot all trees ≥10 cm dbh were measured and identified as far as possible. Maximum tree height was greatest at 200 m (60 m) and least at 850 m (33 m). Tree density (number of individuals ha−1) increased with altitude. The forest at 850 m was the most species- and family-rich, but since the ratio of species to individuals did not vary significantly among altitudes, the higher species richness is attributed partly to the larger number of trees sampled. The Dipterocarpaceae was the most important family in terms of basal area at all altitudes, but its proportion of basal area was much smaller at 850 m than at the other altitudes. The Dipterocarpaceae was the most diverse family at 200 m and 500 m, but at 850 m its diversity was exceeded by the Lauraceae, Myrtaceae and Euphorbiaceae and equalled by the Clusiaceae. The forests at 200 m and 500 m are classified as lowland rain forest and that at 850 m is classified as a lower montane forest.

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Structure, diversity, and spatial patterns in a permanent plot of a high Restinga forest in Southeastern Brazil

Acta Botanica Brasilica ◽

10.1590/s0102-33062011000300017 ◽

2011 ◽

Vol 25 (3) ◽

pp. 633-645 ◽

Cited By ~ 12

Author(s):

Renato Augusto Ferreira de Lima ◽

Alexandre Adalardo de Oliveira ◽

Adriana Maria Zanforlin Martini ◽

Daniela Sampaio ◽

Vinícius Castro Souza ◽

...

Keyword(s):

Tropical Forests ◽

Basal Area ◽

Permanent Plot ◽

Size Class ◽

Tree Density ◽

Southeastern Brazil ◽

White Sand ◽

Younger Age ◽

Sand Forest ◽

Structure Diversity

We assessed the structure, diversity and distribution of tree species in a 10.24-ha permanent plot of high Restinga forest (HRF) in southeastern Brazil. We sampled 15,040 individuals belonging to 45 families, 87 genera and 116 species (density= 1,468 trees ha-1, and basal area= 28.0 m² ha-1). Mean richness was lower than other types of tropical forests and other HRFs that have been less intensively sampled, which is probably due to the younger age and hydromorphy of the soils in the study site. Tree density, basal area, species composition, and diversity all varied considerably depending on the size class considered. The studied plot had a density similar to other tropical forests but with a smaller basal area (fewer individuals > 60 cm in diameter), and higher density of smaller trees. Multi-stemmed individuals were not frequent (11% of the trees), though they were widespread among species (74% of the species). Spatial distribution was predominantly clumped, a pattern common to other types of tropical forests. Besides growing over white-sand soils, the PEIC plot and other white-sand forests of the world also had very similar patterns of community structure, richness and diversity. Therefore, we consider the HRF as a recognizable subtype of white-sand forest.

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Vegetation structure, natural regeneration and management of Parroha community forest in Rupandehi district, Nepal

Scientific World ◽

10.3126/sw.v9i9.5523 ◽

1970 ◽

Vol 9 (9) ◽

pp. 70-81 ◽

Cited By ~ 2

Author(s):

Rajendra Acharya ◽

Babat Babu Shrestha

Keyword(s):

Tree Species ◽

Vegetation Structure ◽

Basal Area ◽

Size Class ◽

Tree Density ◽

Class Diagram ◽

Shrub Layer ◽

Shorea Robusta ◽

Number Of Species ◽

Total Tree

Understanding vegetation structure and regeneration in community forests in important for management planning. The present work was done during September to October 2005. The information on forest management practices was collected by Participatory Rural Appraisal (PRA) which included field observation, interviews and focus group discussion. A total of 125 plant species belonging to 55 families with 36 tree species, 50 shrubs and 39 herbs were recorded from the 0.7 ha sampling area. The total tree density and basal area at South-East (SE) facing slope was 595 pl/ha and 29.68 m²/ha, respectively, where Terminalia alata was the most dominant with highest importance value index (IVI). On the other hand, total tree density and basal area was 453 pl/ha and 41.78 m²/ha, respectively, at South-West (SW) facing slope, where Shorea robusta was the most dominant with the highest IVI. Total shrub/sapling density was 4708 pl/ha at SE slope and 4137 pl/ha at SW slope. Similarly, total herb/seedling density was 10.86 pl/m² at SE slope and 9.79 pl/m² at SW slope. The total number of tree species (S) in tree stage was higher at SE slope than at SW slope and the number of species in shrub layer was higher at SE slope than at SW slope. The two slopes had nearly equal number of species in herbaceous layer. Higher species diversity (H) of different lifeforms was found at SW slope. The SW slope had higher species evenness (J) and Simpson’s index of dominance (C) for all life forms than at SE slope. High similarity index for all tree, shrub/sapling and herb/seedling layers (63.63%, 84.61% and 77.10% respectively) were found between two sites. Alpha (α) diversity for shrub layer was higher at SE slope whereas beta (β) diversity for tree layer was higher at SW slope than at SE slope. Regeneration of Shorea robusta and Terminalia alata was continuous because density increased from tree, sapling to seedlings with a typical reverse J shaped size class diagram at both slope. But regeneration of S. robusta at SW slope was sporadic. The reccurence of forest fire during summer season has appeared as a major problem for the management of forest. The active participation of the local people in forest conservation activities can be effective for sustainable management of forest. Keywords: Community forestry; Vegetation; Regeneration; Size class diagram; Shorea robusta; Terminalia alata. DOI: http://dx.doi.org/10.3126/sw.v9i9.5523 SW 2011; 9(9): 70-81

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Penafsiran Luas Bidang Dasar Tegakan Pinus Merkusii menggunakan Foto Udara di Kesatuan Pemangkuan Hutan (KPH) Kedu Perum Perhutani Unit 1 Jawa Tengah

Forum Geografi ◽

10.23917/forgeo.v23i2.5005 ◽

2009 ◽

Vol 23 (2) ◽

pp. 112

Author(s):

S Sahid

Keyword(s):

Regression Analysis ◽

Aerial Photograph ◽

Basal Area ◽

Tree Height ◽

Tree Density ◽

Stem Diameter ◽

Permanent Plots ◽

Crown Diameter ◽

Pinus Merkusii ◽

Stand Basal Area

The research aim to estimate the basal area of Pinus merkusii combired comprises measurement by aerial photograph with scale of 1:20.000 field and to measurement field. The stand parameters measured are the number of the trees per hectare (N), the tree height (H) and crown diameter (D). Whereas, estimation of the stand basal area was based on the measurement of the stem diameter in the permanent plots. The result of the regression analysis showed that the based area of the Pinus merkusii stand (lbds) had correlation with the number of the trees per hectare (N), the tree height (H) and crown diameter (D), the regression is as follows: Basal areas or tree densities of compartement 100 and 102 have been optimum. Therefore, resin production compartement 100 and 102 is higher than compartement 101 having lower basal are or tree density. It is for those reasons, the compartement 101 needs action to cut the suppressed trees to make optimum basal area.

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Effects of abiotic and biotic factors on Vibrio harveyi ATCC 14126T survival dynamics in seawater microcosms

Aquatic Microbial Ecology ◽

10.3354/ame01910 ◽

2019 ◽

Vol 83 (2) ◽

pp. 109-118 ◽

Cited By ~ 3

Author(s):

M Orruño ◽

C Parada ◽

E Ogayar ◽

VR Kaberdin ◽

I Arana

Keyword(s):

Vibrio Harveyi ◽

Biotic Factors ◽

Abiotic And Biotic Factors

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Effects of Dysbiosis and Dietary Manipulation on the Digestive Microbiota of a Detritivorous Arthropod

Microorganisms ◽

10.3390/microorganisms9010148 ◽

2021 ◽

Vol 9 (1) ◽

pp. 148

Author(s):

Marius Bredon ◽

Elisabeth Depuydt ◽

Lucas Brisson ◽

Laurent Moulin ◽

Ciriac Charles ◽

...

Keyword(s):

Crucial Role ◽

Structure And Function ◽

Ecological Interactions ◽

Dietary Manipulation ◽

Biotic Factors ◽

Abiotic And Biotic Factors ◽

And Function ◽

Multicellular Organisms ◽

Over Time

The crucial role of microbes in the evolution, development, health, and ecological interactions of multicellular organisms is now widely recognized in the holobiont concept. However, the structure and stability of microbiota are highly dependent on abiotic and biotic factors, especially in the gut, which can be colonized by transient bacteria depending on the host’s diet. We studied these impacts by manipulating the digestive microbiota of the detritivore Armadillidium vulgare and analyzing the consequences on its structure and function. Hosts were exposed to initial starvation and then were fed diets that varied the different components of lignocellulose. A total of 72 digestive microbiota were analyzed according to the type of the diet (standard or enriched in cellulose, lignin, or hemicellulose) and the period following dysbiosis. The results showed that microbiota from the hepatopancreas were very stable and resilient, while the most diverse and labile over time were found in the hindgut. Dysbiosis and selective diets may have affected the host fitness by altering the structure of the microbiota and its predicted functions. Overall, these modifications can therefore have effects not only on the holobiont, but also on the “eco-holobiont” conceptualization of macroorganisms.

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Deriving Tree Size Distributions of Tropical Forests from Lidar

Remote Sensing ◽

10.3390/rs13010131 ◽

2021 ◽

Vol 13 (1) ◽

pp. 131

Author(s):

Franziska Taubert ◽

Rico Fischer ◽

Nikolai Knapp ◽

Andreas Huth

Keyword(s):

Size Distribution ◽

Spatial Scales ◽

Basal Area ◽

Tree Height ◽

Tree Size ◽

Diameter Distribution ◽

Forest Inventories ◽

Allometric Relations ◽

Lidar Measurements ◽

Derived Data

Remote sensing is an important tool to monitor forests to rapidly detect changes due to global change and other threats. Here, we present a novel methodology to infer the tree size distribution from light detection and ranging (lidar) measurements. Our approach is based on a theoretical leaf–tree matrix derived from allometric relations of trees. Using the leaf–tree matrix, we compute the tree size distribution that fit to the observed leaf area density profile via lidar. To validate our approach, we analyzed the stem diameter distribution of a tropical forest in Panama and compared lidar-derived data with data from forest inventories at different spatial scales (0.04 ha to 50 ha). Our estimates had a high accuracy at scales above 1 ha (1 ha: root mean square error (RMSE) 67.6 trees ha−1/normalized RMSE 18.8%/R² 0.76; 50 ha: 22.8 trees ha−1/6.2%/0.89). Estimates for smaller scales (1-ha to 0.04-ha) were reliably for forests with low height, dense canopy or low tree height heterogeneity. Estimates for the basal area were accurate at the 1-ha scale (RMSE 4.7 tree ha−1, bias 0.8 m² ha−1) but less accurate at smaller scales. Our methodology, further tested at additional sites, provides a useful approach to determine the tree size distribution of forests by integrating information on tree allometries.

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Adjudicating Perspectives on Forest Structure: How Do Airborne, Terrestrial, and Mobile Lidar-Derived Estimates Compare?

Remote Sensing ◽

10.3390/rs13122297 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2297

Author(s):

Jonathon J. Donager ◽

Andrew J. Sánchez Meador ◽

Ryan C. Blackburn

Keyword(s):

Ponderosa Pine ◽

Laser Scanning ◽

Canopy Cover ◽

Basal Area ◽

Tree Height ◽

Absolute Error ◽

Forest Monitoring ◽

Individual Tree ◽

Structural Configurations ◽

Individual Trees

Applications of lidar in ecosystem conservation and management continue to expand as technology has rapidly evolved. An accounting of relative accuracy and errors among lidar platforms within a range of forest types and structural configurations was needed. Within a ponderosa pine forest in northern Arizona, we compare vegetation attributes at the tree-, plot-, and stand-scales derived from three lidar platforms: fixed-wing airborne (ALS), fixed-location terrestrial (TLS), and hand-held mobile laser scanning (MLS). We present a methodology to segment individual trees from TLS and MLS datasets, incorporating eigen-value and density metrics to locate trees, then assigning point returns to trees using a graph-theory shortest-path approach. Overall, we found MLS consistently provided more accurate structural metrics at the tree- (e.g., mean absolute error for DBH in cm was 4.8, 5.0, and 9.1 for MLS, TLS and ALS, respectively) and plot-scale (e.g., R2 for field observed and lidar-derived basal area, m2 ha−1, was 0.986, 0.974, and 0.851 for MLS, TLS, and ALS, respectively) as compared to ALS and TLS. While TLS data produced estimates similar to MLS, attributes derived from TLS often underpredicted structural values due to occlusion. Additionally, ALS data provided accurate estimates of tree height for larger trees, yet consistently missed and underpredicted small trees (≤35 cm). MLS produced accurate estimates of canopy cover and landscape metrics up to 50 m from plot center. TLS tended to underpredict both canopy cover and patch metrics with constant bias due to occlusion. Taking full advantage of minimal occlusion effects, MLS data consistently provided the best individual tree and plot-based metrics, with ALS providing the best estimates for volume, biomass, and canopy cover. Overall, we found MLS data logistically simple, quickly acquirable, and accurate for small area inventories, assessments, and monitoring activities. We suggest further work exploring the active use of MLS for forest monitoring and inventory.

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Geostatistically modeling stem size and increment in an old-growth forest

Canadian Journal of Forest Research ◽

10.1139/x94-176 ◽

1994 ◽

Vol 24 (7) ◽

pp. 1354-1368 ◽

Cited By ~ 95

Author(s):

Franco Biondi ◽

Donald E. Myers ◽

Charles C. Avery

Keyword(s):

Spatial Patterns ◽

Growth Rates ◽

Spatial Dependence ◽

Basal Area ◽

Tree Density ◽

Individual Growth ◽

Old Growth ◽

Model Estimate ◽

Stem Size ◽

Old Growth Forest

Geostatistics provides tools to model, estimate, map, and eventually predict spatial patterns of tree size and growth. Variogram models and kriged maps were used to study spatial dependence of stem diameter (DBH), basal area (BA), and 10-year periodic basal area increment (BAI) in an old-growth forest stand. Temporal variation of spatial patterns was evaluated by fitting spatial stochastic models at 10-year intervals, from 1920 to 1990. The study area was a naturally seeded stand of southwestern ponderosa pine (Pinusponderosa Dougl. ex Laws. var. scopulorum) where total BA and tree density have steadily increased over the last decades. Our objective was to determine if increased stand density simply reduced individual growth rates or if it also altered spatial interactions among trees. Despite increased crowding, stem size maintained the same type of spatial dependence from 1920 to 1990. An isotropic Gaussian variogram was the model of choice to represent spatial dependence at all times. Stem size was spatially autocorrelated over distances no greater than 30 m, a measure of average patch diameter in this forest ecosystem. Because patch diameter remained constant through time, tree density increased by increasing the number of pine groups, not their horizontal dimension. Spatial dependence of stem size (DBH and BA) was always much greater and decreased less through time than that of stem increment (BAI). Spatial dependence of BAI was close to zero in the most recent decade, indicating that growth rates in 1980–1990 varied regardless of mutual tree position. Increased tree crowding corresponded not only to lower average and variance of individual growth rates, but also to reduced spatial dependence of BAI. Because growth variation was less affected by intertree distance with greater local crowding, prediction of individual growth rates benefits from information on horizontal stand structure only if tree density does not exceed threshold values. Simulation models and area estimates of tree performance in old-growth forests may be improved by including geostatistical components to summarize ecological spatial dependence.

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