scholarly journals Nationwide Assessment of Population Structure, Stability and Plant Morphology of Two Mimusops Species along a Social-Ecological Gradient in Benin, West Africa

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1575
Author(s):  
Gisèle K. Sinasson S. ◽  
Charlie M. Shackleton ◽  
Brice Sinsin
Keyword(s):  
Population Structure ◽  
Structural Characteristics ◽  
Tree Height ◽  
Forest Products ◽  
Tree Regeneration ◽  
Structure Stability ◽  
Ecological Gradient ◽  
Humid Zone ◽  
Ecological Characteristics ◽  
Mean Diameter

Understanding tree species autecology and population structure supports effective conservation actions. Of particular importance are multipurpose trees that provide non-timber forest products (NTFPs). We assessed the population structures and morphologies of two species of NTFP trees in the genus Mimusops across bioclimatic zones in Benin by sampling 288 plots within 11 forests. Structural characteristics were compared between species, forests and zones. Correlations were also observed between Mimusops tree regeneration density, tree features and ecological characteristics. The density of trees ≥5 cm and of regeneration and mean tree height were higher for M. andongensis (within more protected forest) than M. kummel (in forests with access to people), while the highest mean diameter was observed for M. kummel. Tree and regeneration densities and mean height were greatest in the humid zone of Benin, whilst the largest mean diameter was obtained in the sub-humid zone. The results showed significant correlations between regeneration density and soil properties for M. andongensis but not for M. kummel. The correlations between tree morphology and soil characteristics were weak for both species. Ecological characteristics, along with the species’ functional traits and pressures, are important factors related to the observed differences between the species. All diameter classes were represented, and the population seemed more stable in the more protected forest relative to other forests. Mimusops trees with a diameter of 5–15 cm represented more than 30% of this species in most forests; this suggests, for M. kummel, whose trees flower when quite small (≥6 cm dbh), that there are sufficient reproductive trees. Thus, as a long-lived species, its populations could be maintained even with low/episodic recruitment. However, we found no regeneration in many forests and climate change could threaten populations. Therefore, it is important to investigate regeneration growth and dynamics, seed production and germination of the species in relation to the biophysical conditions and disturbances experienced by Mimusops stands.

Flood disturbance and shade stress shape the population structure of açaí palm Euterpe precatoria, the most abundant Amazon species

Botany ◽  
2020 ◽  
Vol 98 (3) ◽  
pp. 147-160
Author(s):  
Heloisa Dantas Brum ◽  
Alexandre F. Souza
Keyword(s):  
Population Structure ◽  
Population Size ◽  
Size Distribution ◽  
Amazon Basin ◽  
Habitat Type ◽  
Forest Products ◽  
Life Stages ◽  
Disturbance Regime ◽  
Human Settlements ◽  
Human Management

Euterpe precatoria Mart. is the most abundant plant species in the Amazon basin, and one of the main non-timber forest products on the continent. A thorough understanding of the ecology of this species is needed to support sustainable management initiatives. Resource availability, disturbance regime, and human management are some of the main factors influencing population structure. We described the species’ life stages, evaluated its allometric relationships, and assessed the effects of habitat type (floodplain and upland) and proximity to human settlements on population size distribution in the Central Amazon near the Purus River. The height:diameter ratio increased from Seedlings to Juvenile 2, but decreased from Juvenile 2 to Reproductive 2, indicating changing height investment for any given diameter along these life stages. There was a marked habitat dependency in both the density and population size distribution, with populations in upland forests dominated by juveniles, whereas populations in the floodplains were dominated by reproductive palms. Proximity to human settlements was not related to population structure parameters. Our results suggest that the disturbance regime may have opposite meanings in várzea forests, where it limits recruitment under increased light levels, and in terra firme forests, where it may stimulate recruitment under limited light conditions.

scholarly journals Population structure and regeneration of Himalayan endemic Larix species in three high-altitude valleys in Nepal Himalaya

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Man Kumar Dhamala ◽  
Prakash Chandra Aryal ◽  
Madan Krishna Suwal ◽  
Sijar Bhatta ◽  
Dinesh Raj Bhuju
Keyword(s):  
Population Structure ◽  
High Altitude ◽  
Graphical Representation ◽  
Anthropogenic Activities ◽  
Tree Height ◽  
Diameter Distribution ◽  
Conservation Area ◽  
Nepal Himalaya ◽  
Regeneration Status ◽  
Management Interventions

Abstract Background The Himalayan forests are of great importance to sustain the nature and community resource demands. These forests are facing pressures both from anthropogenic activities and ongoing global climatic changes. Poor natural regeneration has been considered a major problem in mountainous forests. To understand the population structure and regeneration status of Larix (Larix griffithiana and Larix himalaica), we conducted systematic vegetation surveys in three high-altitude valleys namely Ghunsa (Kanchenjunga Conservation Area, KCA), Langtang (Langtang National Park, LNP), and Tsum (Manaslu Conservation Area, MCA) in Nepal Himalaya. The average values of diameter at breast height (DBH), height, and sapling height were compared for three sites and two species using Kruskal-Wallis test. Population structure was assessed in terms of proportion of seedlings, saplings, and trees. Regeneration was analyzed using graphical representation of frequencies of seedlings, saplings, and trees in histograms. Results The results showed that the population structure of Larix in terms of the proportion of seedling, sapling, and tree varied greatly in the three study areas. KCA had the highest record of seedling, sapling, and tree compared to other two sites. Seedlings were the least among three forms and many plots were without seedlings. We found no seedling in MCA study plots. The plot level average DBH variation among sites was significant (Kruskal-Wallis χ2 = 7.813, df = 2, p = 0.02) as was between species (Kruskal-Wallis χ2 = 5.9829, df = 1, p = 0.014). Similarly, the variation in average tree height was significant (Kruskal-Wallis χ2 = 134.23, df = 2, p < 0.001) among sites as well as between species (Kruskal-Wallis χ2 = 128.01, df = 1, p < 0.001). All the sites showed reverse J-shaped curve but more pronounced for KCA and MCA. In comparing the two species, Larix griffithiana has clear reverse J-shaped diameter distribution but not Larix himalaica. Conclusion The varied responses of Larix manifested through regeneration status from spatially distinct areas show that regeneration limitations might be more pronounced in the future. In all the three studied valleys, regeneration of Larix is found to be problematic and specifically for Larix griffithiana in MCA and Larix himalaica in LNP. To address the issues of disturbances, especially serious in LNP, management interventions are recommended to sustain the unique Himalayan endemic conifer.

scholarly journals A new Vegetation-Plot Database for the Coastal Forests of Kenya

2020 ◽  
Vol 1 ◽  
pp. 103-109 ◽  
Author(s):  
Maria Fungomeli ◽  
Anthony Githitho ◽  
Fabrizio Frascaroli ◽  
Saidi Chidzinga ◽  
Marcus Cianciaruso ◽  
...  
Keyword(s):  
Plant Communities ◽  
Tree Height ◽  
Forest Site ◽  
Biodiversity Hotspots ◽  
Global Index ◽  
Coastal Forests ◽  
Biodiversity Data ◽  
Breast Height ◽  
Mean Diameter ◽  
Tree Identity

Biodiversity data based on standardised sampling designs are key to ecosystem conservation. Data of this sort have been lacking for the Kenyan coastal forests despite being biodiversity hotspots. Here, we introduce the Kenyan Coastal Forests Vegetation-Plot Database (GIVD ID: AF-KE-001), consisting of data from 158 plots, subdivided into 3,160 subplots, across 25 forests. All plots include data on tree identity, diameter and height. Abundance of shrubs is presented for 316 subplots. We recorded 600 taxa belonging to 80 families, 549 of which identified to species and 51 to genus level. Species richness per forest site varied between 43 and 195 species; mean diameter between 13.0 ± 9.8 and 30.7 ± 20.7 cm; and mean tree height between 5.49 ± 3.99 and 12.29 ± 10.61 m. This is the first plot-level database of plant communities across Kenyan coastal forests. It will be highly valuable for analysing biodiversity patterns and assessing future changes in this ecosystem. Taxonomic reference: African Plant Database (African Plant Database version 3.4.0). Abbreviations: DBH = diameter at breast height; GIVD = Global Index of Vegetation-Plot Databases; KECF-VPD = Kenyan Coastal Forests Vegetation Plot Database.

scholarly journals Structural Characteristics of Aerobic Granular Sludge and Factors That Influence Its Stability: A Mini Review

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2726
Author(s):  
Yizhi Hou ◽  
Chunjuan Gan ◽  
Renyu Chen ◽  
Ying Chen ◽  
Shaochun Yuan ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Granular Sludge ◽  
Load Resistance ◽  
Aerobic Granular Sludge ◽  
Future Research ◽  
Structure Stability ◽  
Particle Structure ◽  
Nitrogen And Phosphorus ◽  
Distribution Features ◽  
Study Results

Current extensive research on aerobic granular sludge (AGS) largely focuses on improving its microbial biodiversity, settlement behavior, nitrogen and phosphorus removal efficiency, and shock load resistance. Great challenges that have to be faced are the bottleneck of slow-speed granulation and easy disintegration after granulation, which are key to the extended application of AGS technology. In the present review, the typical morphological structures of AGS are firstly summarized as well as the granulation model hypotheses, and then, we analyze the dominant microflora and their spatial distribution features. The influencing factors on particle structure stability are discussed thereafter on a macro and micro scale. Prospects and future research trends are also discussed based on the current study results for AGS technology.

The structural characteristics and climatic and human impacts of deciduous oak forests in China

2021 ◽  
Author(s):  
Guoping Chen ◽  
Qiong Cai ◽  
Wenjing Fang ◽  
Yuhao Feng ◽  
Jiangling Zhu ◽  
...  
Keyword(s):  
Species Richness ◽  
Spatial Patterns ◽  
Tree Species ◽  
Structural Characteristics ◽  
Tree Height ◽  
Oak Forests ◽  
Oak Forest ◽  
Stem Density ◽  
Shrub Species ◽  
The Mean

Abstract Aims Deciduous oak forest is one of the typical vegetation types in temperate and subtropical mountain zones in China. However, the patterns and determinants of the structural characteristics of these forests remain poorly understood. Methods We investigated 682 oak forest plots across China to characterize the community structures of the oak forests and analyze the underlying factors controlling their spatial patterns. Important Findings Across all plots, the overall mean values were 13.7 cm, 10.0 m, 1468 stems/ha, and 24.3 m 2/ha for the diameter at breast height (DBH), height, stem density and total basal areas (TBA) of trees, respectively. The average species richness was 6 species/600 m 2, 10 species/100 m 2, and 4 species/1 m 2 for the tree, shrub and herb layers, respectively. As latitude increased, the mean tree height, stem density, TBA, tree species richness and shrub species richness decreased, and the mean DBH did not show a significant trend, while species richness of herbs increased significantly. Climatic and anthropogenic variables could explain more variations in mean DBH, mean tree height, TBA, tree species richness, shrub species richness than those in stem density and herb species richness. Further analysis showed that precipitation-related climatic factors were major factors shaping the spatial patterns of community structures. Our findings provide a basis for recognizing the biogeographic patterns of oak forest structures and their responses to global change in China.

Influences of vegetation structure and elevation on CO2 uptake in a mature jack pine forest in Saskatchewan, Canada

2008 ◽  
Vol 38 (11) ◽  
pp. 2746-2761 ◽  
Author(s):  
L. Chasmer ◽  
N. Kljun ◽  
A. Barr ◽  
A. Black ◽  
C. Hopkinson ◽  
...  
Keyword(s):  
Pinus Banksiana ◽  
Structural Characteristics ◽  
Canopy Structure ◽  
Tree Height ◽  
Daily Basis ◽  
Jack Pine ◽  
Co2 Uptake ◽  
Flux Concentration ◽  
Almost All ◽  
Canopy Depth

Carbon dioxide, water vapour, and energy fluxes vary spatially and temporally within forested environments. However, it is not clear to what extent they vary as a result of variability in the spatial distribution of biomass and elevation. The following study presents a new methodology for extracting changes in the structural characteristics of vegetation and elevation within footprint areas, for direct comparison with eddy covariance (EC) CO2 flux concentrations. The purpose was to determine whether within-site canopy structure and local elevation influenced CO2 fluxes in a mature jack pine ( Pinus banksiana Lamb.) forest located in Saskatchewan, Canada. Airborne light detection and ranging (lidar) was used to extract tree height, canopy depth, foliage cover, and elevation within 30 min flux footprints. Within-footprint mean structural components and elevation were related to 30 min mean net ecosystem productivity (NEP) and gross ecosystem production (GEP). NEP and GEP were modeled using multiple regression, and when compared with measured fluxes, almost all periods showed improvements in the prediction of flux concentration when canopy structure and elevation were included. Increased biomass was related to increased NEP and GEP in June and August when the ecosystem was not limited by soil moisture. On a daily basis, fractional cover and elevation had varying but significant influences on CO2 fluxes.

scholarly journals MPB Critical Forest Inventory

2014 ◽  
Vol 90 (04) ◽  
pp. 475-478
Keyword(s):  
Species Composition ◽  
Land Management ◽  
Forest Inventory ◽  
Mountain Pine Beetle ◽  
Tree Height ◽  
Forest Products ◽  
Growth And Yield ◽  
Yield Analysis ◽  
Mountain Pine ◽  
Pine Beetle

The Mountain Pine Beetle epidemic in Alberta has been substantial, with several forest products companies facing a potential decrease in fibre supply as a result. Accurate forest inventory is integral in developing management strategies that effectively address the infestation. Within this context, forest inventory must provide enough species composition detail to allow the design of appropriate harvesting activities. The project evaluated the use of softcopy photo-interpretation and a semi-automated inventory approach to create a forest inventory with a higher level of detail, and looked to advance these methodologies to explore whether metrics such as tree height and volume could also be included. The project also aimed to demonstrate the benefits that such an inventory could provide in growth and yield analysis and within the general framework of integrated land management. Results indicate that the more detailed inventory is useful in addressing forest management challenges associated with the Mountain Pine Beetle infestation and in improving growth and yield analysis, resulting in an overall enhancement to strategic and operational planning. The inventory can also be used for integrated land management, allowing for species composition to be spatially identified within the stand and the identification of other features including anthropogenic disturbance and microsites.

scholarly journals Tree Damage by Ice Accumulation in Norway Spruce (Picea abies (L.) Karst.) Stands Regarding Stand Characteristics

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 679
Author(s):  
Silva Šēnhofa ◽  
Juris Katrevičs ◽  
Andis Adamovičs ◽  
Kārlis Bičkovskis ◽  
Endijs Bāders ◽  
...  
Keyword(s):  
Management Practices ◽  
Slenderness Ratio ◽  
Stand Density ◽  
Tree Height ◽  
Individual Tree ◽  
Tree Damage ◽  
Ice Accumulation ◽  
Mean Diameter ◽  
Overstory Trees ◽  
Stand Characteristics

Freezing rain is a frequently occurring, but relatively rarely studied disturbance in Europe, although ice accumulation may occasionally cause severe damage for forestry. We aimed to characterize ice-accumulation damage to overstory trees in spruce stands, assess the probability of damage based on the stand and individual tree parameters, and define the most significant parameters that affect the probability of individual tree damage in all stands and in recently thinned stands. Among the studied stands, the proportion of damaged overstory spruce ranged from 1.8% to 60.9% and was higher (p < 0.001) in recently thinned stands (27.8% ± 1.9%) than in the other stands (20.4% ± 1.6%). Stem breakage was the prevalent (98.5% ± 1.1%) damage type. At the stand level, the probability of damage decreased for older, less dense stands with a larger mean diameter. Within stands, overstory trees were more damaged (23.5% ± 1.2%; p < 0.001) than those in the lower stand layers, but, within overstory, trees with larger dimensions and a higher social position (high relative diameter and low slenderness ratio) and a higher proportion of crown were less damaged. The probability of breakage to overstory trees was most accurately predicted using almost the same variables for all stands and recently thinned stands. The site type, tree height, relative diameter, and crown ratio were common for both, with the addition of mean diameter at breast height for all stands and the stand density for recently thinned stands. Our results indicate the importance of the tree and stand characteristics on the resistance of individual tree to ice accumulation and the need for management practices that balance increased growth and the stability of trees throughout the rotation.

scholarly journals Height-diameter allometry of tropical forest trees

2011 ◽  
Vol 8 (5) ◽  
pp. 1081-1106 ◽  
Author(s):  
T. R. Feldpausch ◽  
L. Banin ◽  
O. L. Phillips ◽  
T. R. Baker ◽  
S. L. Lewis ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Large Scale ◽  
Amazon Basin ◽  
Stand Structure ◽  
Forest Type ◽  
Structural Characteristics ◽  
Basal Area ◽  
Tree Height ◽  
Geographic Region ◽  
True Value

Abstract. Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical countries. Utilising this database, our objectives were: 1. to determine if H:D relationships differ by geographic region and forest type (wet to dry forests, including zones of tension where forest and savanna overlap). 2. to ascertain if the H:D relationship is modulated by climate and/or forest structural characteristics (e.g. stand-level basal area, A). 3. to develop H:D allometric equations and evaluate biases to reduce error in future local-to-global estimates of tropical forest biomass. Annual precipitation coefficient of variation (PV), dry season length (SD), and mean annual air temperature (TA) emerged as key drivers of variation in H:D relationships at the pantropical and region scales. Vegetation structure also played a role with trees in forests of a high A being, on average, taller at any given D. After the effects of environment and forest structure are taken into account, two main regional groups can be identified. Forests in Asia, Africa and the Guyana Shield all have, on average, similar H:D relationships, but with trees in the forests of much of the Amazon Basin and tropical Australia typically being shorter at any given D than their counterparts elsewhere. The region-environment-structure model with the lowest Akaike's information criterion and lowest deviation estimated stand-level H across all plots to within amedian −2.7 to 0.9% of the true value. Some of the plot-to-plot variability in H:D relationships not accounted for by this model could be attributed to variations in soil physical conditions. Other things being equal, trees tend to be more slender in the absence of soil physical constraints, especially at smaller D. Pantropical and continental-level models provided less robust estimates of H, especially when the roles of climate and stand structure in modulating H:D allometry were not simultaneously taken into account.

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