scholarly journals Stand-level windthrow patterns and long-term dynamics of surviving trees in natural secondary stands after a stand-replacing windthrow event

2019 ◽  
Vol 92 (4) ◽  
pp. 473-480 ◽  
Author(s):  
Masato Shibuya ◽  
Satoshi Ishibashi
Keyword(s):  
Tree Mortality ◽  
Basal Area ◽  
Tree Density ◽  
Permanent Plots ◽  
Natural Forests ◽  
Canopy Layer ◽  
Breast Height ◽  
Composition And Structure ◽  
Initiation Stage

Abstract We examined typhoon windthrow patterns in stand-scale permanent plots within three natural forests and the long-term dynamics of surviving trees in two of these plots. The aim was to verify whether pre-disturbance composition and structure affected windthrow damage and stand recovery. The stands, which were in Hokkaido, the northernmost main island of Japan, differed in pre-disturbance composition (coniferous, mixed and broadleaved stands) and structure, and the basal area losses by the windthrow event were 81–93 per cent. Tree mortality was significantly related to tree size (diameter at breast height) and species. The windthrow patterns differed among the three stands; and, windthrow severity was affected by the pre-disturbance composition and structure. The mortality of trees that survived the windthrow event was ~60 per cent in the two plots. The surviving trees comprised a majority of the canopy layer in the secondary stands. The relative basal area of surviving trees decreased rapidly with increasing tree density in the stand initiation stage but differed between plots. Consequently, the pre-disturbance composition and structure influenced windthrow severity, stand recovery and secondary succession in the recovered stands.

scholarly journals Long-Term Effects of Fuels Treatments, Overstory Structure, and Wildfire on Tree Regeneration in Dry Forests of Central Washington

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 888
Author(s):  
Allison K. Rossman ◽  
Jonathan D. Bakker ◽  
David W. Peterson ◽  
Charles B. Halpern
Keyword(s):  
Prescribed Burning ◽  
Basal Area ◽  
Tree Regeneration ◽  
Dry Forest ◽  
Permanent Plots ◽  
Long Term Effects ◽  
Fuels Reduction ◽  
Forest Fuels ◽  
Fuels Treatments

The long-term effectiveness of dry-forest fuels treatments (restoration thinning and prescribed burning) depends, in part, on the pace at which trees regenerate and recruit into the overstory. Knowledge of the factors that shape post-treatment regeneration and growth is limited by the short timeframes and simple disturbance histories of past research. Here, we present results of a 15-year fuels-reduction experiment in central Washington, including responses to planned and unplanned disturbances. We explore the changing patterns of Douglas-fir regeneration in 72 permanent plots (0.1 ha) varying in overstory abundance (a function of density and basal area) and disturbance history—the latter including thinning, prescribed burning, and/or wildfire. Plots were measured before treatment (2000/2001), soon afterwards (2004/2005), and more than a decade later (2015). Thinning combined with burning enhanced sapling recruitment (ingrowth) into the overstory, although rates of ingrowth were consistently low and greatly exceeded by mortality. Relationships between seedling frequency (proportion of quadrats within a plot) and overstory abundance shifted from weakly negative before treatment to positive after thinning, to neutral in the longer term. However, these relationships were overshadowed by more recent, higher-severity prescribed fire and wildfire that stimulated seedling establishment while killing advanced regeneration and overstory trees. Our results highlight the dependence of regeneration responses on the history of, and time since, fuels treatment and subsequent disturbance. Managers must be aware of this spatial and temporal complexity and plan for future disturbances that are inevitable but unpredictable in timing and severity.

scholarly journals Long-Term Data from Fields Recovering after Sugarcane, Banana, and Pasture Cultivation in Ecuador

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Randall W. Myster
Keyword(s):  
Life Form ◽  
Basal Area ◽  
Percent Cover ◽  
Old Field ◽  
Breast Height ◽  
Crop Types ◽  
Set Up ◽  
Maquipucuna Reserve ◽  
Term Data

I report here on an ongoing permanent plot study in areas recovering from agriculture in Ecuador. These plots were set up in 1995 at Maquipucuna Reserve where the forest is tropical lower montane. The study consists of replicate fields in three past crop types (Sugarcane, Banana, and Pasture) for a total of six fields. Each field was first divided into 25 continuous 2 m × 5 m subplots which together form a 10 m × 25 m plot with the longest side bordering the adjacent forest. Then starting in 1996, and continuing annually every year since, each subplot has been sampled for percent cover of all plants and diameter at breast height (dbh) for all trees whose dbh is greater than or equal to 1 cm. I have used that data in these published studies: (1) species composition and life form, richness, and basal area trends, (2) computation of all positive and negative pairwise species associations, (3) relationships between richness and productivity over time, (4) dominance-diversity curves, and (5) definition and quantification of old field plant communities. Finally with the help of the LTER program in Puerto Rico, this sampling continues, with 2012 marking the sixteenth year of continuous annual sampling.

scholarly journals Estimating Structure and Biomass of a Secondary Atlantic Forest in Brazil Using Fourier Transforms of Vertical Profiles Derived from UAV Photogrammetry Point Clouds

2020 ◽  
Vol 12 (21) ◽  
pp. 3560 ◽  
Author(s):  
André Almeida ◽  
Fabio Gonçalves ◽  
Gilson Silva ◽  
Rodolfo Souza ◽  
Robert Treuhaft ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Atlantic Forest ◽  
Fourier Transforms ◽  
Basal Area ◽  
Point Clouds ◽  
Tree Density ◽  
Vertical Profiles ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
3D Point Clouds

Knowing the aboveground biomass (AGB) stock of tropical forests is one of the main requirements to guide programs for reducing emissions from deforestation and forest degradation (REDD+). Traditional 3D products generated with digital aerial photogrammetry (DAP) have shown great potential in estimating AGB, tree density, diameter at breast height, height, and basal area in forest ecosystems. However, these traditional products explore only a small part of the structural information contained in the 3D data, thus not leveraging the full potential of the data for inventory purposes. In this study, we tested the performance of 3D products derived from DAP and a technique based on Fourier transforms of vertical profiles of vegetation to estimate AGB, tree density, diameter at breast height, height, and basal area in a secondary fragment of Atlantic Forest located in northeast Brazil. Field measurements were taken in 30 permanent plots (0.25 ha each) to estimate AGB. At the time of the inventory, we also performed a digital aerial mapping of the entire forest fragment with an unmanned aerial vehicle (UAV). Based on the 3D point clouds and the digital terrain model (DTM) obtained by DAP, vertical vegetation profiles were produced for each plot. Using traditional structure metrics and metrics derived from Fourier transforms of profiles, regression models were fit to estimate AGB, tree density, diameter at breast height, height, and basal area. The 3D DAP point clouds represented the forest canopy with a high level of detail, regardless of the vegetation density. The metrics based on the Fourier transform of profiles were selected as predictors in all models produced. The best model for AGB explained 93% (R2 = 0.93) of the biomass variation at the plot level, with an RMS error of 9.3 Mg ha−1 (22.5%). Similar results were obtained in the models fit for the tree density, diameter at breast height, height, and basal area, with R2 values above 0.90 and RMS errors of less than 18%. The use of Fourier transforms of profiles with 3D products obtained by DAP demonstrated a high potential for estimating AGB and other forest variables of interest in secondary tropical forests, highlighting the value of UAV as a low-cost tool to assist the implementation of REDD+ projects in developing countries like Brazil.

Changes in the floristic composition of cerrado sensu stricto in Brazil over a nine-year period

2000 ◽  
Vol 16 (4) ◽  
pp. 579-590 ◽  
Author(s):  
Jeanine Maria Felfili ◽  
Alba Valéria Rezende ◽  
Manoel Cláudio Da Silva Júnior ◽  
Marco Aurélio Silva
Keyword(s):  
Species Composition ◽  
Tropical Forests ◽  
Basal Area ◽  
Floristic Composition ◽  
Ground Level ◽  
Sensu Stricto ◽  
Permanent Plots ◽  
Constant Density ◽  
Composition And Structure

Changes in floristic composition and structure in a cerrado sensu stricto area were studied over a 9-y period. A sample of 19 (20-m × 50-m) permanent plots was assessed at 3-y intervals from 1985 to 1994, when all stems ≥ 5 cm at 0.30 m above the ground level were measured. There was little change in species composition over the period. Changes in density and basal area of the whole community were in the range of 5% over the 9 y. These parameters fluctuated over the years with the greatest differences found in the comparisons of 1991, 2 y after an accidental fire reached the site, with other years. The changes in density and basal area were greater than in several tropical forests, probably due to disturbances such as fire occurring at 3 to 5-y intervals. The nearly constant density and basal area suggested a highly resilient community.

scholarly journals Análisis comparativo de la vegetación de fundo legal y la vegetación madura en el poblado de Yaxcabá, Yucatán, México

2019 ◽  
Vol 97 (1) ◽  
pp. 50 ◽  
Author(s):  
Perla Victoria Rodríguez-Sánchez ◽  
Samuel Israel Levy-Tacher ◽  
Neptalí Ramírez-Marcial ◽  
Erin Estrada-Lugo
Keyword(s):  
Ecosystem Services ◽  
Vegetation Structure ◽  
Sustainable Use ◽  
Basal Area ◽  
Tree Density ◽  
Soil Types ◽  
Main Function ◽  
Composition And Structure ◽  
Structural Differences ◽  
Post Hoc

<p><strong>Background:</strong> The fundo legal (FL) represents a strip of vegetation that surrounds many towns in the Yucatan Peninsula. The main function of the FL is the provision of ecosystem services.</p><p><strong>Hypothesis:</strong> Does the composition and structure of the FL vegetation differ from the mature vegetation (VM) of the Yaxcabá municipal seat? / The FL and the VM are similar in terms of their floristic richness but not in their structure.</p><p><strong>Place and dates of study:</strong> In the VM and the vegetation of the FL of the municipal seat of Yaxcabá, Yucatán from February to July 2017.</p><p><strong>Methods:</strong> They were made 32 sampling units (SU) located in the predominant soil types (hollum and kankab); 24 SU were performed within the FL and 8 SU in the VM. In each SU, all individuals &gt; 2.5 cm in diameter were recorded. The richness and diversity of species was compared between FL and VM through rarefaction to standardize the sampling effect and through a linear model and a post hoc test the structural differences between both types of vegetation could be defined.</p><p><strong>Results:</strong> The results revealed similarity in richness, tree density and species diversity between FL vegetation and VM. However, the basal area was significantly lower in FL.</p><strong>Conclusions:</strong> The formal differences between the vegetation structure of the FL with respect to VM show us that the sustainable use of FL is possible.

scholarly journals LONG-TERM RELATIONSHIP BETWEEN OAK DECLINE AND SHRUB GROWTH DYNAMICS IN AN HUNGARIAN OAK FOREST, 1972-2017

AGROFOR ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Tamás MISIK ◽  
Imre KÁRÁSZ
Keyword(s):  
Growth Dynamics ◽  
Basal Area ◽  
Tree Density ◽  
Oak Forest ◽  
Oak Decline ◽  
Shrub Layer ◽  
Cornus Mas ◽  
Oak Trees ◽  
Oak Tree

Long-term structural dynamics of shrub layer of temperate oak forest communities were not extensively reported in published studies. The serious oak decline was first reported in 1979-80 and nowadays 63.0% of canopy oak trees died in a forest stand. The data were used to obtain (1) quantitative information on shrub layer growth, including height (H) and shoot diameter (DSH) condition and basal area (BA) values; (2) structural information on foliage cover rate of the shrub layer, mean cover of some shrub species; (3) comprehensive description from the ecological processes in the shrub layer in the last 45 years and our objective was (4) to analyze the possible effects of oak decline on the shrub growth dynamics. The following measurements were carried out in the 48 × 48 m plot: shoot height, shoot diameter, basal area and foliage cover of each individuals in the high shrub layer. Correlation analysis confirmed that significant positive relations were between mean H, mean DSH of the dominant woody species (Acer campestre, Acer tataricum and Cornus mas) and oak tree density between 1972 and 2017. The decreasing oak tree density did not show detectable impact to the co-dominant shrubs growth. There was a low significant association between number of oak trees and basal area of high shrub layer. Finally, there was a statistically significant interaction between mean cover of A. campestre and C. mas and oak trees. The findings of the study indicate that forest responded to oak decline with significant structural rearrangement in the shrub layer.

scholarly journals IMPACTS ON VEGETATION AFTER SELECTIVE CUTTING IN FOREST CONCESSION AREA IN THE SOUTHWESTERN BRAZILIAN AMAZON

FLORESTA ◽  
2020 ◽  
Vol 50 (4) ◽  
pp. 1778
Author(s):  
Raquel Helena Felberg Jacobsen ◽  
Marta Silvana Volpato Sccoti ◽  
Suelen Thaina Silva Fagundes ◽  
João Fideles de Brito Junior ◽  
Scheila Cristina Biazatti
Keyword(s):  
Plant Density ◽  
Forest Harvesting ◽  
Forest Monitoring ◽  
Permanent Plots ◽  
Natural Forests ◽  
Before And After ◽  
Future Supply ◽  
Cutting Rate ◽  
One Year

The forest monitoring after exploration activities is an important tool for forest management, helping to plan the use of forest resources. This research aimed to evaluate the impacts on tree vegetation after one year of the end of forest harvesting in concession area in the Jamari National Forest, RO. The vegetation was evaluated before and after the exploitation in an Annual Production Unit (APU) with cutting rate of 14.14 m³ ha-1. In total, seven permanent plots of 0.5 ha were divided and randomly distributed, where all individuals with diameter at breast height (DBH) ≥ 10 cm were evaluated. Impact evaluation was based on two criteria, the diversity and structure of vegetation (phytosociological, parametric, diametric, and internal). There was a reduction of 2% in plant density and loss of two species. The volumetric supply decreased in the classes above 80 cm of DBH and the diametric structure maintained the largest supply of plants in the lower classes. The exploration activities collaborated in 3.57% to increase the mortality rate, besides causing slight and severe damages in 15 ind.ha-1. The quality of the stem was predominantly straight (82.36%). The damage observed is within the expected limits for areas with low cut rates and subjected to reduced impact exploration techniques. We suggest the continuous monitoring in the medium- and long- term in order to describe the patterns of regeneration and growth of species, mainly logging, projecting the future supply of cutting.Keywords: Management in natural forests; Forest dynamics; Forest concession.

Dynamics of dead wood in old-growth hemlock–hardwood forests of northern Wisconsin and northern Michigan

1994 ◽  
Vol 24 (8) ◽  
pp. 1672-1683 ◽  
Author(s):  
Lucy E. Tyrrell ◽  
Thomas R. Crow
Keyword(s):  
Tree Mortality ◽  
Structural Integrity ◽  
Dead Wood ◽  
Woody Debris ◽  
Basal Area ◽  
Exponential Model ◽  
Decay Rates ◽  
Permanent Plots ◽  
Old Growth ◽  
Northern Michigan

We studied the dynamics of coarse woody debris (logs and snags) in old-growth forests by estimating rates of tree mortality, snag change, and log decay in hemlock–hardwood stands located in northern Wisconsin and northern Michigan. To estimate mortality and snag changes, we recensused live trees and dead snags in permanent plots in 15 stands. We also recorded recent mortality along transects, and noted category of mortality (standing death, breakage, or uprooting) for gap-maker trees and logs in 25 stands. Decay rates were estimated from a simple exponential model of wood density from log sections against the age of the wood since tree death, and from ages of trees growing on decaying "nurse" logs. From data obtained in permanent plots, annual tree mortality averaged 0.9% original basal area, 0.9% original live tree density, and 4.8 trees/ha. Of the three categories of tree mortality, standing death accounted for 62% of all mortality, while breakage represented 25%, and uprooting, 13%. Based on origin of logs, species composition affected category of mortality. Eastern hemlock (Tsugacanadensis (L.) Carr.) was significantly more prone to uprooting while yellow birch (Betulaalleghaniensis Britton) and paper birch (Betulapapyrifera Marsh.) were less prone to uprooting than expected if independence of species and categories of mortality were assumed (χ2 = 216.5, df = 14, p < 0.001). Changes in snags (fragmentation to shorter snags or collapse at the base) occurred for <7% of the original snags annually. Fragmentation occurred for 2.1 snags/(ha × year), and collapse for 1.3 snags/(ha × year). We estimated that it takes nearly 200 years for hemlock logs to lose structural integrity and become partially incorporated into the soil. At >350 years, the two oldest hemlock–hardwood stands had accumulated volumes of logs >65 m3/ha distributed among all decay classes, and appeared to be at a dead wood equilibrium in which rates of log production from mortality balance rates of wood loss by decay.

scholarly journals Relationship Between Edaphic Factors and Vegetation in Savannas of the Brazilian Midwest Region

2015 ◽  
Vol 39 (3) ◽  
pp. 821-829 ◽  
Author(s):  
Michellia Pereira Soares ◽  
Paula Reys ◽  
Daniel Salgado Pifano ◽  
Janaílson Leônidas de Sá ◽  
Patrícia Oliveira da Silva ◽  
...  
Keyword(s):  
Soil Properties ◽  
Species Abundance ◽  
Basal Area ◽  
Floristic Composition ◽  
Chemical Analyses ◽  
Breast Height ◽  
Composition And Structure ◽  
Midwest Region ◽  
Abundance And Distribution ◽  
Physical And Chemical

The Brazilian savanna is a mosaic of phytophysiognomies influenced by edaphic and topographic factors that range from the occurrence of fires to anthropic disturbance. The goal of this study was a comparative analysis between two cerrado areas in southeastern Goiás, relating the floristic composition and structure of the vegetation to soil properties to better understand the physiognomic characteristics of the region. Twenty-five 20 × 20 m plots were used. All plants with circumference at breast height of more than 15 cm were measured. Soil samples collected at a depth of 0-20 cm were subjected to physical and chemical analyses. Canonical correspondence analysis (CCA) was used to detect possible correlations between the soil properties and species abundance and distribution. The density and total basal area were 1,647 ind/ha and 15.57 m2/ha, respectively, in Ouroana. At this site, 107 species were sampled. In Montes Claros de Goiás, the density and total basal area were 781 ind/ha and 17.62 m2/ha, and 120 species were sampled. The soil texture of Ouroana was sandy and significantly different from the medium to clayey texture of Montes Claros. The soils of both areas are dystrophic, however, more fertile in Montes Claros and aluminum-toxic in Ouroana. The species of vegetation were distributed according to soil fertility levels. The CCAs grouped species according to soil properties that defined location and abundance as well as the phytophysiognomies of the studied areas.

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

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.

Sign in / Sign up

Export Citation Format

Share Document