scholarly journals Participatory Forestry Improves Mangrove Forest Management in Kenya

2020 ◽  
Author(s):  
Anne Kairu ◽  
Kiplagat Kotut ◽  
Robert Mbeche ◽  
James Gitundu Kairo
Keyword(s):  
Mangrove Forest ◽  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
The State ◽  
Mangrove Forests ◽  
Managed Forests ◽  
Managed Forest ◽  
Western Block ◽  
Participatory Forestry

Abstract Background: Mangrove forests worldwide are highly valued for their social, ecological and environmental roles. Participatory forestry has been recognized as a tool for improvement of forest conditions. The current study assessed impacts of PFM implementation on structure and regeneration of mangroves at Gazi Bay, Kenya. Forest data was collected along belt transects perpendicular to waterline in both community and state managed blocks. Results: Basal area and standing density were significantly higher in the co-managed forests (16 m2 ha-1 and 4,341 tree ha-1) as compared to the state managed forests (eastern block 10.3 m2 ha-1 and 2,673 trees ha-1; western block 6.2 m2 ha-1 and 2,436 trees ha-1). There were significantly higher (p = 0.0068) densities of quality class poles in co-managed forest block as compared to state-managed eastern and western blocks. Natural regeneration values of 38,822 juveniles ha-1 in the co-managed central block and 23,556 and 35,061 juveniles ha-1 in the state managed eastern and western blocks respectively are considered adequate to support recovery of the forest. A higher complexity index (CI) recorded in the co-managed mangrove forest compared to the state managed eastern and western blocks is particularly due to improved stand density, tree height, and biomass resulting from increased surveillance and protection by the community. The results have wide implications in the management of mangroves for community and biodiversity benefits and climate change mitigation.Conclusion: The results support community participation for improved management of mangrove forests and are in conformity with sectoral policies on natural resources management in Kenya.

scholarly journals Participatory forestry improves mangrove forest management in Kenya

2021 ◽  
Vol 23 (1) ◽  
pp. 41-54
Author(s):  
A. Kairu ◽  
K. Kotut ◽  
R. Mbeche ◽  
J. Kairo
Keyword(s):  
Forest Management ◽  
Mangrove Forest ◽  
Sustainable Forest Management ◽  
Basal Area ◽  
Mangrove Forests ◽  
Managed Forests ◽  
Participatory Forest Management ◽  
Tropical Forest Management ◽  
Western Block ◽  
Participatory Forestry

Participatory forestry has been recognized as a tool for improving tropical forest management. The current study assessed the impacts of participatory forest management (PFM) on the structure and regeneration of a mangrove forest at Gazi Bay, Kenya. Data were collected along belt transects perpendicular to the waterline in both co-managed and state-managed mangrove forests. Basal area and standing density were significantly higher in the co-managed mangrove forests (16 m2/ha and 4 341 tree/ha) as compared to the state forests (eastern block 10.3 m2/ha and 2 673 trees/ha; western block 6.2 m2/ha and 2 436 trees/ha). There were significantly higher (p = 0.0068) densities of merchantable poles in community-managed as compared to state-managed forests. Natural regeneration patterns in community-managed and state-managed forests were deemed adequate to support the recovery of both forests. The results demonstrate that community participation contributes to improved management of mangrove forests and is in agreement with the principles of sustainable forest management.

scholarly journals A new species of Sarcofahrtiopsis (Insecta, Diptera, Sarcophagidae) from mangrove forests in the Brazilian Amazon, with a key to species identification

2017 ◽  
Vol 47 (4) ◽  
pp. 349-354
Author(s):  
Fernando da Silva CARVALHO-FILHO ◽  
Caroline Costa de SOUZA ◽  
Jéssica Maria Menezes SOARES
Keyword(s):  
New Species ◽  
Species Identification ◽  
Mangrove Forest ◽  
Brazilian Amazon ◽  
The State ◽  
Mangrove Forests ◽  
Congeneric Species ◽  
Key To Species ◽  
A New Species

ABSTRACT A new species of Sarcofahrtiopsis Hall, 1933, S. terezinhae sp. nov., is described based on male specimens collected in traps baited with rotting crabs in a mangrove forest in the state of Pará, eastern Brazilian Amazon. This species differs from congeneric species in having vesica with a row of toe-like projections. We provide a key to the species of the genus.

scholarly journals Regional Height–Diameter Equations for Major Tree Species of Southwest Oregon

2007 ◽  
Vol 22 (3) ◽  
pp. 213-219 ◽  
Author(s):  
Hailemariam Temesgen ◽  
David W. Hann ◽  
Vincente J. Monleon
Keyword(s):  
Relative Position ◽  
Tree Species ◽  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
Individual Tree ◽  
Fit Statistics ◽  
Alternative Measures ◽  
Southwest Oregon ◽  
Accuracy Of Prediction

Abstract Selected tree height and diameter functions were evaluated for their predictive abilities for major tree species of southwest Oregon. Two sets of equations were evaluated. The first set included four base equations for estimating height as a function of individual tree diameter, and the remaining 16 equations enhanced the four base equations with alternative measures of stand density and relative position. The inclusion of the crown competition factor in larger trees (CCFL) and basal area (BA), which simultaneously indicates the relative position of a tree and stand density, into the base height–diameter equations increased the accuracy of prediction for all species. On the average, root mean square error values were reduced by 45 cm (15% improvement). On the basis of the residual plots and fit statistics, two equations are recommended for estimating tree heights for major tree species in southwest Oregon. The equation coefficients are documented for future use.

Incorporating intertree competition into an ecosystem model

1995 ◽  
Vol 25 (3) ◽  
pp. 413-424 ◽  
Author(s):  
R.L. Korol ◽  
S.W. Running ◽  
K.S. Milner
Keyword(s):  
Process Model ◽  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
Ecosystem Model ◽  
Growth And Yield ◽  
Maintenance Respiration ◽  
Tree Diameter ◽  
Diameter Increment ◽  
Individual Trees

Current research suggests that projected climate change may influence the growth of individual trees. Therefore, growth and yield models that can respond to potential changes in climate must be developed, TREE-BGC, a variant of the ecosystem process model FOREST-BGC, calculates the cycling of carbon, water, and nitrogen in and through forested ecosystems. TREE-BGC allocates stand-level estimates of photosynthesis to "each tree using a competition algorithm that incorporates tree height, relative radiation-use efficiency, and absorbed photosynthetically active radiation, TREE-BGC simulated the growth of trees grown in a dense and an open stand of interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) near Kamloops, B.C. The competition algorithm dynamically allocated stand estimates of photosynthesis to individual trees, and the trees were grown using an allometric relationship between biomass increment and height and diameter increment. Asymptotic height growth and the changes in the height–diameter relationship with competition were also incorporated in the model algorithms. Sapwood and phloem volume were used to calculate maintenance respiration. Predicted reductions in diameter growth with stand density were similar to those observed in the study stands. Although the carbon balance of individual trees was not tested, simulated tree diameter increments and height increments were correlated with the actual measurements of tree diameter increment (r2 = 0.89) and tree height increment (r2 = 0.78) for the 5-year period (n = 352). Although the model did not work well with trees that had diameters <5 cm, the model would be appropriate for a user who required an accuracy of ± 0.03 m3•ha−1 for volume, ± 0.02 m2•ha−1 for basal area, or ± 0.4 m for tree height over a 5-year period.

scholarly journals Practical Extension of a Lake States Tree Height Model

2008 ◽  
Vol 25 (4) ◽  
pp. 186-194 ◽  
Author(s):  
Don C. Bragg
Keyword(s):  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
Site Index ◽  
Individual Response ◽  
White Pine ◽  
Eastern White Pine ◽  
Tree Model ◽  
Individual Tree ◽  
Height Model

Abstract By adapting data from national and state champion lists and the predictions of an existing height model, an exponential function was developed to improve tree height estimation. As a case study, comparisons between the original and redesigned model were made with eastern white pine (Pinus strobus L.). For example, the heights predicted by the new design varied by centimeters from the original until the pines were more than 25 cm dbh, after which the differences increased notably. On a very good site (50-year base age site index [SI50] = 27.4 m) at the upper end of the range of basal area (BA; 68.9 m2/ha) for the region, the redesigned model predicted a champion-sized eastern white pine (actual measurements: 97.0 cm dbh, 50.9 m tall) to be 51.3 m tall, compared with 38.8 m using the original formulation under the same conditions. The NORTHWDS Individual Response Model (NIRM) individual tree model further highlighted the influence of these differences with long-term simulations of eastern white pine height. On a moderate site (SI50 = 18.7 m) with intermediate (BA = 15 m2/ha) stand density, NIRM results show that the original model consistently predicts heights to be 20–30% lower for mature white pine.

Spatiotemporal dynamics of mangrove forest and association with strandings of Antillean manatee (Trichechus manatus) calves in Paraíba, Brazil

2021 ◽  
pp. 1-8
Author(s):  
Iara Dos Santos Medeiros ◽  
Vanessa Araújo Rebelo ◽  
Sebastião Silva Dos Santos ◽  
Rafael Menezes ◽  
Nadjacleia Vilar Almeida ◽  
...  
Keyword(s):  
Mangrove Forest ◽  
Spatiotemporal Dynamics ◽  
The State ◽  
Influential Factor ◽  
Eastern Region ◽  
Northern Coast ◽  
Mangrove Forests ◽  
Trichechus Manatus ◽  
The North ◽  
North Eastern

Abstract Estuaries in Brazil are highly threatened environments and habitat loss is the main influential factor for the increase in the number of strandings of Antillean manatee (Trichechus manatus) calves in the north-eastern region of the country. The aim of the present study was to analyse and quantify the spatiotemporal dynamics of mangroves in the state of Paraíba and the association with manatee calf stranding events. The study area encompassed 10 remaining mangroves along the coast of the state, four of which were located within protected areas. Information on the mangrove forests was obtained from satellite images from the last four decades. Data on stranded Antillean manatee calves were obtained from a databank with records from 1980 to 2019. The data were analysed using geoprocessing techniques and statistical analyses. The results demonstrated changes in the mangrove forest over time, with larger areas existing during the 1980s, reductions in the following periods but a slight increase in the last decade. The number of stranded Antillean manatee calves increased over the years, with stranding events concentrated mainly on the northern coast of the state. The smallest number of stranding events occurred in the 1980s, when the mangrove forests were larger. Our findings confirm that the integrity of mangroves is of extreme importance to the maintenance and sustainability of Antillean manatee populations.

Estimation of foliage area in dense Montana lodgepole pine stands

1987 ◽  
Vol 17 (4) ◽  
pp. 320-324 ◽  
Author(s):  
Roger D. Hungerford
Keyword(s):  
Lodgepole Pine ◽  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
Area Ratio ◽  
Density Range ◽  
Sapwood Area ◽  
Crown Length ◽  
Pine Stands

Six stands of lodgepole pine, Pinuscontorta ssp. latifolia (Engelm.) Critchfield, in Montana were sampled to evaluate sapwood area (at 1.37 m and the crown base), basal area (at 1.37 m), tree height, and crown length as predictors of foliage area. Densities of the six stands ranged from 2900 to 17 800 stems/ha. This density range was picked to determine how stand density affects the ratio of foliage area to basal sapwood area. Regression estimates of foliage area using basal area and sapwood area at 1.37 m and the crown base were equally good. Within the sampled range of stand densities, differences in the foliage area to sapwood area ratio were not significant. The amount of foliage area served per unit of sapwood area (at 1.37 m) averaged 0.25 m2/cm2 for all 54 trees sampled. This value of foliage area per unit of sapwood area in dense stands was smaller than most other published values.

scholarly journals Relationship analysis of vegetation structural properties and the aboveground carbon stock of mangrove forest

2020 ◽  
Vol 200 ◽  
pp. 02020
Author(s):  
Eva Purnamasari ◽  
Muhammad Kamal ◽  
Pramaditya Wicaksono
Keyword(s):  
Structural Properties ◽  
Mangrove Forest ◽  
Canopy Cover ◽  
Tree Height ◽  
Mangrove Ecosystem ◽  
Mangrove Forests ◽  
Mangrove Species ◽  
Relationship Analysis ◽  
Aboveground Carbon ◽  
Mangrove Tree

Mangrove forests have important ecological functions as a controller of environmental quality in coastal areas and absorber of atmospheric carbon. The mangrove ecosystem has a unique vegetation structure which form vegetation zonation that consists of different forest stands characteristics and tree species. This study aims to analyze the relationship between vegetation structural properties and the estimated aboveground carbon (AGC) stock of mangrove forest in Bedul mangrove, Banyuwangi, East Java, Indonesia. The study was conducted by field observation at some purposively selected sample locations. Field measurement was aimed to collect data about mangrove tree diameter at breast height (DBH), species, tree height, and fractional canopy cover. Mangrove biomass was indirectly calculated by allometric method based on mangrove species to estimate AGC in mangrove stands. The highest total AGC found in this study was 114.09 tons/ha at Rhizophora mucronata dominated forest, while the lowest total AGC was 12.86 tons/ha with Ceriops tagal as the dominant species. The AGC estimation in mangrove stands correlated positively with DBH and tree height. However, the biomass content and AGC are affected by the number of mangrove stands. The difference in the number of stands affect the amount of carbon content at each sample point.

scholarly journals EFECTOS DE LA DENSIDAD DE PLANTACIÓN Y LA ALTURA DE PODA SOBRE LA PRODUCCION DE Pinus taeda L. A LOS 5 AÑOS DE EDAD

FLORESTA ◽  
2003 ◽  
Vol 33 (1) ◽  
Author(s):  
Ruben Costas ◽  
Patricio Mac Donagh ◽  
Elizabeth Weber ◽  
Pedro Irschick ◽  
José Palavecino
Keyword(s):  
Pinus Taeda ◽  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
High Density ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Pinus Taeda L

En un ensayo con 3 niveles de densidad y 11 niveles de altura de poda, se evaluaron los efectos de la densidad, la altura de poda y la interacción entre ambas sobre la producción de la masa de Pinus taeda L. a los 5 años de edad. Las variables sobre las cuales se analizó la producción fueron el volumen por unidad de superficie, el área basal, el volumen individual, el diámetro a la altura de pecho y la altura.Se observaron mayores volumen por unidad de superficie y área basal y menores volúmenes individuales y los diámetros a la altura de pecho en los tratamientos con mayor densidad. Para todas las variables respuestas, excepto la altura, se observó que en general a mayor altura de poda se produjeron valores medios menores y viceversa.La interacción entre densidad y altura de poda no fue significativa para ninguna de las variables respuestas. STAND DENSITY AND PRUNE HEIGTH EFFECTS OVER FIVE YEAR OLD YIELD PLANTATION OF Pinus taeda L. Abstract The effects of the stand density and prune height, and the interaction between them, have been evaluated over the yield of five years old Pinus taeda plantation. There were three density levels and eleven prune heights. There were analyzed volume per hectare, basal area, tree volume, diameter at breast height (dbh) and height. It were found higher volume and basal area per hectare, and lower tree volume and dbh for the high density treatments. Except tree height, all the others variables showed lower average values with the increasing of the prune height. The interaction between stand density and prune height was not significant for all analyzed variables.

Ten-year tree mortality following a jack pine budworm outbreak in Saskatchewan

1998 ◽  
Vol 28 (12) ◽  
pp. 1784-1793 ◽  
Author(s):  
W Jan A Volney
Keyword(s):  
Pinus Banksiana ◽  
Tree Mortality ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
Jack Pine ◽  
Jack Pine Budworm ◽  
Individual Trees

The fate of jack pine (Pinus banksiana Lamb.) trees growing in a variety of stand conditions was assessed annually for a decade following an outbreak of jack pine budworm (Choristoneura pinus Freeman) in central Saskatchewan. Mortality was clearly associated with the severity and damage sustained by the trees during the second year of the defoliation episode. The pattern of mortality was remarkably similar among stands that originated in decades that spanned 60 years. Mortality rates were highest in stands that originated in the 1890s and were lowest in stands of the most recent origin (1940s). Defoliation severity, the length of dead top, diameter at breast height, and relative tree height expressed as a standard normal variable accounted for 94% of the variability in survival time. A nonparametric proportional hazards model was developed to evaluate the relative risk of individual trees dying. Defoliation is an important process in determining stand density, basal area, and volume after juvenile stand development is complete. The results presented suggest a novel method to determine the hazard of trees in stands and thus assess the vulnerability of stands to future budworm attack.

Sign in / Sign up

Export Citation Format

Share Document