Small-Scale Variations in Species Composition of Miombo Woodland in Sengwa, Zimbabwe: The Influence of Edaphic Factors, Fire and Elephant Herbivory

2001 ◽  
Vol 71 (2) ◽  
pp. 935 ◽  
Author(s):  
I. Mapaure
Keyword(s):  
Species Composition ◽  
Small Scale ◽  
Edaphic Factors ◽  
Miombo Woodland

Scales of heterogeneity in prairie and forest

1999 ◽  
Vol 77 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Heather R Kleb ◽  
Scott D Wilson
Keyword(s):  
Species Composition ◽  
Small Scale ◽  
Light Penetration ◽  
Pocket Gopher ◽  
Available N ◽  
Litter Mass ◽  
Thomomys Talpoides ◽  
Mixed Grass ◽  
Below Ground ◽  
Aspen Forest

Few studies have compared scales of heterogeneity among plant communities. We predicted that differences in the sizes of dominant species should allow us to detect small-scale (<256 cm) heterogeneity in mixed-grass prairie but not in adjacent aspen forest. We examined light penetration, soil moisture, available N, elevation, species composition, and plant mass at 10 locations in prairie and forest in both spring and summer. Variables were measured in 1-cm2 plots arranged in pairs separated by 0-256 cm. Several variables in prairie (elevation, litter mass, light penetration, and species composition) showed significant evidence for scale within the range examined. In contrast, only one variable in forest (light penetration in summer) showed evidence for scale in the same range. The scale of heterogeneity in prairie was consistent with the scale of two possible causes, species composition and elevation variability due to northern pocket gopher (Thomomys talpoides Richardson) activity, both of which varied significantly in prairie but not in forest. Whereas some aboveground factors (light and litter mass) varied within the range examined, belowground factors (water and N) did not, suggesting that the scale of heterogeneity differs between above- and below-ground factors. In total, the results suggest that differences in the scale of heterogeneity between prairie and forest reflect the relative sizes of the dominant plants.Key words: aspen, forest, heterogeneity, light, nitrogen, prairie, scale, soil, water.

Variability in organic matter lost by combustion in a boreal bog during the 2001 Chisholm fire

2003 ◽  
Vol 33 (12) ◽  
pp. 2509-2513 ◽  
Author(s):  
Brian W Benscoter ◽  
R Kelman Wieder
Keyword(s):  
Organic Matter ◽  
Species Composition ◽  
Spatial Variability ◽  
Spatial Variation ◽  
Fire Severity ◽  
Small Scale ◽  
Western Canada ◽  
Direct Combustion ◽  
Site Variation

Fire directly releases carbon (C) to the atmosphere through combustion of biomass. An estimated 1470 ± 59 km2 of peatland burns annually in boreal, western Canada, releasing 4.7 ± 0.6 Tg C to the atmosphere via direct combustion. We quantified within-site variation in organic matter lost via combustion in a bog peatland in association with the 116 000-ha Chisholm, Alberta, fire in 2001. We hypothesized that for peatlands with considerable small-scale microtopography (bogs and treed fens), hummocks will burn less than hollows. We found that hollows exhibit more combustion than hummocks, releasing nearly twice as much C to the atmosphere. Our results suggest that spatial variability in species composition and site hydrology within a landform and across a landscape could contribute to considerable spatial variation in the amounts of C released via combustion during peatland fire, although the magnitude of this variation may be dependent on fire severity.

The vertical gradient of bark pH of twigs and macrolichens in a Picea abies canopy not affected by acid rain

2001 ◽  
Vol 33 (4) ◽  
pp. 353-359 ◽  
Author(s):  
Thale Kermit ◽  
Yngvar Gauslaa
Keyword(s):  
Picea Abies ◽  
Species Composition ◽  
Acid Rain ◽  
Vertical Gradient ◽  
Small Scale ◽  
High Ph ◽  
Ph Values ◽  
Constant Ph ◽  
Horizontal Variation ◽  
Cyanobacterial Lichens

AbstractThe pH of 192 thin, even-aged twigs from 4 height levels of 12 randomly selected trees within a boreal Picea abies canopy naturally exposed to rainfall with a high pH (>5·2) was measured. The largest variation in bark pH was due to the height above the ground. However, a highly significant horizontal variation between trees was also found, apparently due to small-scale soil variations. The biomass of alectorioid lichens increased with increasing height above die ground to at least 12 m, a height interval with fairly constant pH values. The uppermost twigs had an unusually high pH and an abnormal species composition for P. abies, with dominance of the foliose Melanelia exasperatula. The canopy hosted several cyanobacterial lichens, but these were scattered and had low biomass, restricted to lower branches of the trees with the highest bark pH.

scholarly journals Influence of edaphic factors on the structure and distribution of plant species in and around Mekeiman Marsh Wetland, Northeast of Algeria

2021 ◽  
Vol 22 (6) ◽  
Author(s):  
Moundji Touarfia ◽  
NOUREDDINE BOUALI ◽  
ABDELKADER DJOUAMAA ◽  
MOHAMED CHERIF MAAZI ◽  
MOUSSA HOUHAMDI
Keyword(s):  
Environmental Factors ◽  
Species Composition ◽  
Plant Species ◽  
Principal Component ◽  
Freshwater Wetland ◽  
Plant Species Composition ◽  
Edaphic Factors ◽  
Marsh Wetland ◽  
Plant Assemblages ◽  
Species Composition And Distribution

Abstract. Touarfia M, Bouali N, Djouamaa Ak, Maazi MC, Houhamdi M. 2021. Influence of edaphic factors on the structure and distribution of plant species in and around Mekeiman Marsh Wetland, Northeast of Algeria. Biodiversitas 22: 3219-3228. Understanding the environmental factors that influence plant species composition and distribution is essential for successful management of biodiversity. Hence, the purpose of the present study was to assess plant species composition and distribution in a freshwater wetland Mekeiman Marsh, Northeastern Algeria and to analyze the influence of environmental factors on local plant species. To explore the distribution of plant species in this Marsh and analyze their associations with edaphic soil factors, the mapping and types of plant species in this area were analyzed by MapInfo and principal component analysis (PCA) ordination. For this purpose, four stations were chosen according to a stratified sampling method and phytosociological surveys were carried out in 12 plots, which were sampled using the Braun- Blanquet method. Multivariate analyses were used to determine the relationship between plant species distribution and edaphic factors. The R i386 (version 4.0.3) software was used for data analysis. We have identified 48 plant species belonging to 21 families. Results of biological types in the study area revealed the dominance of hemicryptophytes and therophytes, which indicates the presence of therophytization in this Marsh. Spatial distribution maps showed that plant species were divided into two categories viz. sparse and scattered plants according to the humidity gradient. The most important edaphic factors associated with plant species in Mekeiman Marsh were Sodium, Phosphorus, active limestone, Magnesium, clay, organic matter, C/N and Azot. By combining mapping and influence of edaphic factors on the structure and distribution of plant species in this wetland, it was known that the plant assemblages of this Marsh make disproportionately important contributions to wetland-level diversity. By combining mapping and influence of edaphic factors on the structure and distribution of plant species in this wetland, the plant assemblages of this Marsh make disproportionately important contributions to wetland-level diversity.

scholarly journals Edaphic factors controlling soil organic matter and C storage in miombo woodlands, Zambia

2021 ◽  
Author(s):  
Reuben Lembani ◽  
Jasper Knight
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Management Practices ◽  
Sub Saharan Africa ◽  
Edaphic Factors ◽  
Miombo Woodlands ◽  
Miombo Woodland ◽  
Large Variability ◽  
Tree Structures ◽  
Successional Stages

Soil organic matter (SOM) is a key component of forest productivity and soil organic carbon stock. However, little is known about SOM and C variability in miombo woodlands which is a significant ecosystem in sub-Sahara African forests and vital for REDD+ strategies. In this study, nine edaphic factors were measured and used to analyse the variability of SOM in miombo woodland sites with different tree structures in Luanshya, Zambia. The findings showed a large variability of SOM stocks at different soil depths: 36.67 to 113.89 Mg ha-1 at 0–10 cm depth, 28.67 to 79.56 Mg ha-1 at 10–20 cm depth, and 31.89 to 98.56 Mg ha-1 at 20–30 cm depth. These SOM values at different depths also varied between miombo woodland sites of different successional stages, notably that areas affected by recent tree clearance had higher than average SOM content per layer (0–10 cm: +5.57%; 10–20 cm: +4.20%; 20–30 cm: +4.30%). Canonical correspondence analysis (CCA) revealed that the most significant environmental factors influencing SOM were woodland thinning by clearance, and silt content within soils. This study highlights that CCA can be used to show the relative importance of different forest successional stages as a function of management practices, as well as edaphic factors, in determining miombo soil SOM content. The results of this study are particularly relevant for addressing current REDD+ reforestation and management strategies that are aimed at increasing carbon stocks in the tropical forests of sub-Saharan Africa.

scholarly journals Large-area inventory of species composition using airborne laser scanning and hyperspectral data

Silva Fennica ◽  
2021 ◽  
Vol 55 (4) ◽  
Author(s):  
Hans Ørka ◽  
Endre Hansen ◽  
Michele Dalponte ◽  
Terje Gobakken ◽  
Erik Næsset
Keyword(s):  
Forest Management ◽  
Species Composition ◽  
Laser Scanning ◽  
Hyperspectral Data ◽  
Airborne Laser Scanning ◽  
Tree Level ◽  
Small Scale ◽  
Large Area ◽  
Airborne Laser ◽  
Species Specific

Tree species composition is an essential attribute in stand-level forest management inventories and remotely sensed data might be useful for its estimation. Previous studies on this topic have had several operational drawbacks, e.g., performance studied at a small scale and at a single tree-level with large fieldwork costs. The current study presents the results from a large-area inventory providing species composition following an operational area-based approach. The study utilizes a combination of airborne laser scanning and hyperspectral data and 97 field sample plots of 250 m collected over 350 km of productive forest in Norway. The results show that, with the availability of hyperspectral data, species-specific volume proportions can be provided in operational forest management inventories with acceptable results in 90% of the cases at the plot level. Dominant species were classified with an overall accuracy of 91% and a kappa-value of 0.73. Species-specific volumes were estimated with relative root mean square differences of 34%, 87%, and 102% for Norway spruce ( (L.) Karst.), Scots pine ( L.), and deciduous species, respectively. A novel tree-based approach for selecting pixels improved the results compared to a traditional approach based on the normalized difference vegetation index.22Picea abiesPinus sylvestris

Characterisation of small-scale stand types in a mixed hardwood forest

1990 ◽  
Vol 55 ◽  
Author(s):  
J. Neirynck ◽  
N. Lust
Keyword(s):  
Soil Moisture ◽  
Species Composition ◽  
Tree Species ◽  
Environmental Variables ◽  
Leaf Decomposition ◽  
Hardwood Forest ◽  
Small Scale ◽  
Chemical Characteristics ◽  
Tree Species Composition ◽  
Intensive Research

Gradients  in soil moisture, texture, nutrient state and spacing patterns enable us to  divide stands into separate substands, which have their own tree species  composition and structures. Nevertheless, such a separation is just the  beginning of a set of conclusions and observations. It is based upon  differences in flora and chemical characteristics. As a matter of fact, every  separate sub stand has its own microclimate in which a well defined complex  of environmental variables regulates regeneration, flora presence and leaf  decomposition.     The results of such an intensive research should lead to the improvement of  the stand tending.

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