scholarly journals The environment and vegetation of the flux measurement site near Skukuza, Kruger National Park

Koedoe ◽  
2001 ◽  
Vol 44 (1) ◽  
Author(s):  
R.J. Scholes ◽  
N. Gureja ◽  
M. Giannecchinni ◽  
D. Dovie ◽  
B. Wilson ◽  
...  
Keyword(s):  
Woody Plant ◽  
Clayey Soil ◽  
Basal Area ◽  
Flux Measurement ◽  
Wide Band ◽  
Maximum Height ◽  
Crown Cover ◽  
Sclerocarya Birrea ◽  
Other Substances ◽  
Combretum Apiculatum

The SAFARI-2000 intensive study site is located 13 km WSW of Skukuza. Detailed measurements of the exchanges of energy, water, carbon dioxide and other substances between the savanna and the atmosphere have been made there since April 2000. This paper provides basic information regarding the climate, soils and vegetation at the site. The site is located near the top of a gentle rise in an undulating granitic landscape. Most of the data were collected within a 300 m square centred on the flux tower situated at [email protected]' S, [email protected]' E and oriented true north. The tower stands exactly on the ecotone between a ridgetop broad-leafed Combretum savanna on sandy soil and a midslope fme-leafed Acacia savanna on clayey soil. The ecotone is marked by a 10 m wide band of sedges. The tree basal area within the sample square was 6.8 mVha (@ 1.0 standard error), the tree density 128 @ 16 plants/ha and the tree crown cover 24 @ 4 . Shrubs, defined as woody plants greater than 0.5 m but less than 2.5 m tall, contributed a further 7.6 crown cover. The basal area weighted mean height of the trees was 9 m, and the maximum height 13m. Nineteen woody plant species were recorded within the square, with 70 of the woody plant basal area dominated by Combretum apiculatum, Sclerocarya birrea and Acacia nigrescens. The rooted basal area of grasses was 7.1 @ 0.6 and in June 2000 the grass standing crop was 400 g DM m2.

INVESTIGATING SILVICULTURAL CHARACTERISTICS OF YEW (TAXUS BACCATA L.) STAND USING FULL-CALLIPERING IN NORTHERN FORESTS OF IRAN

2013 ◽  
Vol 06 (01) ◽  
pp. 1250067 ◽  
Author(s):  
MIR MOZAFFAR FALLAHCHAI ◽  
SEYED ARMIN HASHEMI ◽  
GASEM RAHANJAM
Keyword(s):  
Distribution Curve ◽  
Basal Area ◽  
Diameter Distribution ◽  
Maximum Height ◽  
Taxus Baccata ◽  
Height Distribution ◽  
Annual Increment ◽  
Restricted Area ◽  
Northern Forests ◽  
Low Rate

In this research, some of site and silvicultural characteristics of Yew stand in northern forests of Iran was studied. For this purpose, compartment number 16 of district 4 Shir-ghalaye was selected. According to research purposes, stands with an area of 20 ha were chosen in center of the compartment and was separated from map. Due to restricted area of region and according to few number of Yew trees in the stand, the full-callipering method was conducted for measuring quantitative and qualitative characteristics. In the stand diameter at breast height (D.B.H.), height and canopy diameter of all Yew trees were measured. The results showed that the diameter distribution curve and height distribution curve of Yew trees were similar to even-age forests curve. But according to average annual increment, mixture type of Yew trees in stand, diameter distribution of other species and low rate regeneration of Yew, it can be concluded that the studied Yew stand, is an uneven-age stand and because of low rate regeneration in previous years the number of young Yew trees were reduced and even-age forest curve was formed subsequently. The maximum height and diameter of Yew trees were recorded 26.8 m and 112 cm, respectively. Also, the number of trees per hectare and basal area per hectare of Yew trees were calculated 14.55 and 3.23 m2 respectively.

Relationships between Ligustrum sinense Invasion, Biodiversity, and Development in a Mixed Bottomland Forest

2013 ◽  
Vol 6 (1) ◽  
pp. 175-186 ◽  
Author(s):  
Justin L. Hart ◽  
Brittany N. Holmes
Keyword(s):  
Plant Species ◽  
Woody Plant ◽  
Basal Area ◽  
Active Management ◽  
Ligustrum Sinense ◽  
Development Patterns ◽  
Woody Plant Species ◽  
Spearman's Rho ◽  
Spearman’S Rho ◽  
Bottomland Forest

AbstractInvasion of closed canopy forests by shade-tolerant alien plants has the potential to modify species composition, stand structure, ecosystem function, and long-term forest development patterns. Ligustrum sinense is a shade-tolerant alien shrub that has invaded bottomland forests throughout the southeastern United States. This species has received comparatively little attention in the literature despite its potential to drastically alter invaded sites. The overarching goal of our study was to document the relationships between Ligustrum sinense invasion and woody plant biodiversity and development patterns in an intact southeastern U.S. bottomland forest. The forest was dominated by Quercus nigra and Liquidambar styraciflua. Ligustrum sinense ranked fifth in basal area contribution, occurred in 97% of our plots, and represented 95% of all understory stems. Spearman's rho for dominance (based on basal area of stems > 5 cm diameter at breast height [dbh]) of L. sinense and woody plant species richness for each plot revealed a significant negative relationship (rs = −0.69, P < 0.01). A similar relationship was revealed between L. sinense density and woody plant species diversity (rs = −0.78, P < 0.01) and evenness (rs = −0.82, P < 0.01). Spearman's rho for L. sinense density and native understory stem density (individuals ≥ 1 m height, < 5 cm dbh) also revealed a significant negative association (rs = −0.48, P < 0.01). Under the current disturbance regime and without active management, we projected the forest would shift to support a stronger component of L. sinense and that structure would transition from tree to shrub dominance for sites within the forest.

scholarly journals Container Size and Planting Zone Influence on Transplant Survival and Growth of Two Coastal Plants

2005 ◽  
Vol 15 (3) ◽  
pp. 554-559 ◽  
Author(s):  
Mack Thetford ◽  
Debbie Miller ◽  
Kathryn Smith ◽  
Mica Schneider
Keyword(s):  
Basal Area ◽  
Shoot Biomass ◽  
Maximum Height ◽  
Transplant Survival ◽  
Coastal Plants ◽  
Root Shoot Ratio ◽  
Canopy Area ◽  
The Mean ◽  
Air Force Base ◽  
Santa Rosa Island

Survival and subsequent growth of two beach species produced in containers of differing volume and depth were evaluated following transplant on Eglin Air Force Base, Santa Rosa Island, Fla. Rooted cuttings of gulf bluestem (Schizachyrium maritimum) were produced in four container types: 1-gal (gallon), 0.75-gal treepot, 1-qt (quart), or 164-mL Ray leach tube (RLT) containers. Root and shoot biomass of gulf bluestem harvested after 12 weeks in container production were greatest for plants grown in treepot containers and root: shoot ratio decreased as container size increased. Regardless of container size, survival of beach-planted gulf bluestem was 100%. Basal area of plants from standard gallon and treepot containers was similar 11 months after transplant and basal area for plants from treepot containers remained greater than plants from quart or RLT containers. Effect of planting zone [92, 124, 170, and 200 m landward of the Gulf of Mexico (Gulf)] on transplant survival was also evaluated for inkberry (Ilex glabra). Seedling liners of inkberry were produced in 3-gal treepot or gallon containers. Inkberry was taller when grown in 3-gal treepot containers than when grown in gallon containers. Regardless of container size, all inkberry planted 92 m from the Gulf died. Inkberry survival (>75%) when grown in 3-gal treepot containers was two to six times greater than plants grown in gallon containers (15%, 50%, 40%; 124, 170, and 200 m from Gulf, respectively). After 15 months, inkberry grown in 3-gal treepot containers remained larger with 1.5 times the mean maximum height and twice the mean canopy area compared to those grown in gallon containers.

Regeneration of Vegetation in the Brisbane Ranges After Fire and Infestation by Phytophthora cinnamomi

1985 ◽  
Vol 33 (1) ◽  
pp. 15 ◽  
Author(s):  
P Dawson ◽  
G Weste ◽  
D Ashton
Keyword(s):  
Population Density ◽  
Seed Production ◽  
Phytophthora Cinnamomi ◽  
Basal Area ◽  
First Record ◽  
Inoculum Density ◽  
Crown Cover ◽  
Bush Fire ◽  
Crown Density ◽  
Sclerophyll Forest

The distribution, population density and regeneration of some prominent spp. of understorey and overstorey (dominant Eucalyptus spp.) were monitored over a period of 20 yr in seasonally well drained dry sclerophyll forest. Changes varied with susceptibility to the pathogen and to fire. Changes in spp. composition and crown density of the overstorey were attributed to fire. Population density, basal area and crown cover of the Eucalyptus spp. which were associated with the pathogen, also declined in 1962-82. Both distribution and population density of Xanthorrhoea australis and Isopogon ceratophyllus declined markedly following the spread of infestation, whereas those of Hakea sericea and Lepidosperma semiteres increased. Regeneration of X. australis but not of I. Ceratophyllus was observed in certain areas of the infested plots 12-20 years after infection. This is the first record of such regeneration. It is postulated that a bush fire in 1967 both stimulated X. australis seed production and reduced further an already declining pathogen inoculum density.

Multitemporal LiDAR improves estimates of fire severity in forested landscapes

2018 ◽  
Vol 27 (9) ◽  
pp. 581 ◽  
Author(s):  
Michael S. Hoe ◽  
Christopher J. Dunn ◽  
Hailemariam Temesgen
Keyword(s):  
Spatial Information ◽  
Mean Squared Error ◽  
Fire Severity ◽  
Three Dimensional ◽  
Basal Area ◽  
Point Clouds ◽  
Fire Effects ◽  
Maximum Height ◽  
Ecological Resources ◽  
Change In Mean

Landsat-based fire severity maps have limited ecological resolution, which can hinder assessments of change to specific resources. Therefore, we evaluated the use of pre- and post-fire LiDAR, and combined LiDAR with Landsat-based relative differenced Normalized Burn Ratio (RdNBR) estimates, to increase the accuracy and resolution of basal area mortality estimation. We vertically segmented point clouds and performed model selection on spectral and spatial pre- and post-fire LiDAR metrics and their absolute differences. Our best multitemporal LiDAR model included change in mean intensity values 2–10 m above ground, the sum of proportion of canopy reflection above 10 m, and differences in maximum height. This model significantly reduced root-mean-squared error (RMSE), root-mean-squared prediction error (RMSPE), and bias when compared with models using only RdNBR. Our top combined model integrated RdNBR with LiDAR return proportions <2 m above ground, pre-fire 95% heights and pre-fire return proportions <2 m above ground. This model also significantly reduced RMSE, RMSPE, and bias relative to RdNBR. Our results confirm that three-dimensional spectral and spatial information from multitemporal LiDAR can isolate disturbance effects on specific ecological resources with higher accuracy and ecological resolution than Landsat-based estimates, offering a new frontier in landscape-scale estimates of fire effects.

A woody plant community and tree-cacti associations change with distance to a water source in a dry Chaco forest of Argentina

2017 ◽  
Vol 39 (1) ◽  
pp. 15 ◽  
Author(s):  
Carolina B. Trigo ◽  
Andrés Tálamo ◽  
Mauricio M. Núñez-Regueiro ◽  
Enrique J. Derlindati ◽  
Gustavo A. Marás ◽  
...  
Keyword(s):  
Species Composition ◽  
Plant Community ◽  
Woody Plant ◽  
Spatial Association ◽  
Basal Area ◽  
Water Source ◽  
Grazing Pressure ◽  
Water Sources ◽  
Woody Vegetation ◽  
Total Species Richness

In semiarid regions, livestock is concentrated around water sources generating a piosphere pattern (gradients of woody vegetation degradation with increasing proximity to water). Close to the water source, livestock may affect the composition, structure and regeneration strategies of woody vegetation. We used the proximity from a water source as a proxy of grazing pressure. Our objectives were (1) to compare woody vegetation attributes (richness, diversity, species composition, density and basal area) and ground cover between sites at two distances to a water source: near (higher grazing pressure) and far from the water source (lower grazing pressure), and (2) to quantify and compare cases of spatial association among the columnar cacti Stetsonia coryne (Salm-Dyck) Britton and Rose (Cactaceae), and the dominant tree Bulnesia sarmientoi Lorentz ex Griseb. (Zygophyllaceae). We used a paired design with eight pairs of rectangular plots distributed along a large and representative natural water source. We found lower total species richness, plant density and soil cover near than far from water source, and more cases of spatial associations between the two species studied. Our results show evidence of increased livestock impacts around water sources. However, we found no difference in terms of species composition or basal area at near versus far sites. We conclude that grazing pressure might be changing some attributes of the woody plant community, and that the association of young trees with thorny plants (grazing refuge) could be a regeneration mechanism in this semiarid forest with high grazing pressure.

Relationships between loblolly pine yield and woody plant diversity in Virginia Piedmont plantations

1999 ◽  
Vol 29 (7) ◽  
pp. 1065-1072 ◽  
Author(s):  
Lisa E Schabenberger ◽  
Shepard M Zedaker
Keyword(s):  
Species Richness ◽  
Loblolly Pine ◽  
Plant Diversity ◽  
Woody Plant ◽  
Basal Area ◽  
Plant Species Richness ◽  
Shannon Index ◽  
Vegetation Control ◽  
Virginia Piedmont ◽  
Competition Control

This study was established to determine the effects of competition control on loblolly pine (Pinus taeda L.) yield and woody plant diversity in Virginia Piedmont plantations 12-14 years of age. In a factorial experiment, loblolly pine and competing woody vegetation were analyzed at eight levels of competition control: total, two-thirds, one-third, or no woody stem control in combination with either total or no herbaceous vegetation control. Pine yield increased linearly with increasing levels of woody control intensity. As woody control increased, noncrop woody plant basal area and woody plant diversity (Shannon index (H')) in the canopy decreased. Woody plant species richness in the canopy was reduced by herbaceous control and by total woody control. Percent woody cover, H', and species richness in the understory were not affected at any level of competition control. Regression analysis was used to examine relationships between loblolly pine yield, noncrop woody dominance and canopy plant diversity (H'). Pine yield was negatively correlated (R2 = 0.74) with the percentage of noncrop woody basal area (PNCW BA) in the canopy, while canopy diversity was proportional to PNCW BA (R2 = 0.97). Canopy diversity was inversely related to pine yield (R2 = 0.77), with a high trade-off in diversity at low yield levels, but with decreasing sensitivity as pine yield increased.

A re-assessment of effects of fire on miombo regeneration in the Zambian Copperbelt

1988 ◽  
Vol 4 (4) ◽  
pp. 361-372 ◽  
Author(s):  
E. N. Chidumayo
Keyword(s):  
Species Diversity ◽  
Plant Growth ◽  
Fire Protection ◽  
Woody Plant ◽  
Basal Area ◽  
Abundant Species ◽  
Stem Density ◽  
Miombo Woodland ◽  
Breast Height ◽  
Canopy Species

ABSTRACTIn 1933/34 eight coppice plots were established in Brachystegia-Julbemardia (miombo) woodland at Ndola in the Copperbelt area of Zambia by the Forestry Department. These plots have been maintained under fire protection, annual early or late dry season burning since 1934/35. Before establishment stems over 20.3 cm girth at breast height were enumerated. Three of the eight plots (one fire protected and two annually early burnt) were enumerated in 1982, 48–49 years after establishment. In addition, a coppice plot at Chitwi, 16 km southwest of the Ndola plots, cleared in 1972 and left to regenerate naturally was enumerated in May 1982 and August 1986 to assess woody plant growth.The density of stems over 20.0 cm girth in the 13-year-old coppice at Chitwi was 2.5 times that in an adjacent shelterbelt woodland. The stem density in the fire protected plot at Ndola in 1982 was 86% of the pre-felling density while in one of the early burnt plots it was 95% of the pre-felling density. The protected plot had the lowest species diversity after 49 years, largely because of the loss of 11 understorey species that were present before felling.There were no significant differences in stem mean girth at breast height (gbh) of canopy species in the Ndola plots under fire protection and early burning regimes. Mean annual gbh increments of abundant species were estimated at 1.17–2.21 cm yr−1 and 0.59–1.42 cm yr−1 during 0–9 and 0–49 year age-periods, respectively. Estimated mean annual basal area increments for stems over 30 cm gbh were 0.35 m2 ha−1 for the 13-year-old coppice and 0.24–0.27 m2 ha−1 for the 49-year-old coppice. These results indicate a decrease in both gbh and basal area increment with increasing age of miombo coppice

scholarly journals Impact of Shrimp Ponds on Mangrove Blue Carbon Stocks in Ecuador

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 816
Author(s):  
Jéssica Merecí-Guamán ◽  
Fernando Casanoves ◽  
Diego Delgado-Rodríguez ◽  
Pablo Ochoa ◽  
Miguel Cifuentes-Jara
Keyword(s):  
Climate Change ◽  
Soil Depth ◽  
Basal Area ◽  
Carbon Stocks ◽  
Mitigation Strategies ◽  
Tidal Range ◽  
Maximum Height ◽  
Shrimp Ponds ◽  
Ecosystem Carbon ◽  
Shrimp Farms

Mangrove forests play an important role in mitigating climate change but are threatened by aquaculture expansion. The inclusion of mangroves in climate change mitigation strategies requires measuring of carbon stocks and the emissions caused by land use change over time. This study provides a synthesis of carbon stocks in mangrove and shrimp ponds in the Gulf of Guayaquil. In this study area, we identified 134,064 ha of mangrove forest and 153,950 ha of shrimp farms. Two mangrove strata were identified according to their height and basal area: medium-statured mangrove (lower height and basal area) and tall mangrove (greater height and basal area). These strata showed statistical differences in aboveground carbon stocks. In both strata, the most abundant mangrove species was Rhizophora mangle. For both strata, trees had a maximum height (>30 m), and their density was greater than 827 ha−1. Total ecosystem level carbon stocks (measured to 1 m soil depth) were 320.9 Mg C ha−1 in medium-statured mangroves and 419.4 Mg C ha−1 in tall mangroves. The differences are attributable to higher basal area, soil organic carbon concentrations and salinity, tidal range, origin of allochthonous material, and herbivory patterns. Mangrove soils represented >80% of the total ecosystem carbon. Ecosystem carbon stocks were lower (81.9 Mg C ha−1) in the shrimp farms, 50% less than in undisturbed mangroves. Our results highlight mangroves as tropical ecosystems with extremely high carbon storage; therefore, they play an important role in mitigating climate change. This research provides a better understanding of how carbon stocks in this gulf are found and can be used for design strategies to protect global natural carbon sinks.

scholarly journals Dynamics of juvenile woody plant communities on termite mounds in a West African savanna landscape

2014 ◽  
Vol 17 ◽  
pp. 28-41
Author(s):  
Arne Erpenbach ◽  
Rüdiger Wittig ◽  
Karen Hahn
Keyword(s):  
Plant Communities ◽  
Woody Plants ◽  
Woody Plant ◽  
Keystone Species ◽  
Structural Complexity ◽  
Basal Area ◽  
West African ◽  
Termite Mound ◽  
Termite Mounds ◽  
Vegetation Zone

Termites are keystone species in savanna ecology, and their mounds are thought to be an important source of habitat heterogeneity and structural complexity of the savanna. Macrotermes termitaria have been shown to allow woody plant colonisation of landscapes otherwise dominated by C4 grasses. In this study, we assess how resource-rich Macrotermes mounds affect juvenile woody plant and non-woody plant species diversity, community composition, biomass and population dynamics. We repeatedly sampled paired termite mound and savanna plots in Pendjari National Park (Sudanian vegetation zone, North Benin, West Africa) over the course of two years. Despite considerable overlap in their species pools, plant communities of mound and savanna plots were clearly separated in ordinations. Species richness and diversity of juvenile woody plants was consistently higher on termite mounds, while no differences could be detected for non-woody plants. Evenness of juvenile woody plants was generally lower on mounds, whereas density and basal area were higher on mounds. In contrast, we did not detect any influence of the mound microhabitat on colonisation, mortality and turnover of woody juveniles. Therefore, we suggest that differences in the communities on and off mounds should be strongly influenced by directed diaspore dispersal through zoochory.

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