scholarly journals Vegetation-environment relationships in a catchment containing a dambo in central Zimbabwe

Bothalia ◽  
2001 ◽  
Vol 31 (1) ◽  
pp. 135-143 ◽  
Author(s):  
I. Mapaure ◽  
M. P. McCartney
Keyword(s):  
Species Composition ◽  
Species Distribution ◽  
Southern Africa ◽  
Environmental Variables ◽  
Small Scale ◽  
Plant Water ◽  
Vegetation Composition ◽  
Vegetation Map ◽  
Small Catchment ◽  
Detailed Classification

Seasonally saturated wetlands, known as dambos. are a common landscape element throughout much of southern  Africa. The diversity of species composition within catchments containing dambos is widely attributed to hydrological conditions, but plant-water relationships are poorly established. In this paper a detailed classification and a vegetation map are presented for a small catchment in central Zimbabwe containing a dambo. Canonical Correspondence Analysis has been applied to explore the link between vegetation composition and environmental variables. This confirms that water is a key influence in species distribution and small-scale patterning of vegetation within the catchment.

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.

Phytosociology and gradient analysis of a subalpine treed fen in Rocky Mountain National Park, Colorado

1996 ◽  
Vol 74 (8) ◽  
pp. 1203-1213 ◽  
Author(s):  
J. Bradley Johnson
Keyword(s):  
Species Composition ◽  
Correspondence Analysis ◽  
Species Distribution ◽  
Gradient Analysis ◽  
Vegetation Type ◽  
Detrended Correspondence Analysis ◽  
Tree Density ◽  
Small Scale ◽  
Groundwater Temperature ◽  
Strong Control

The vegetation of a subalpine fen in Colorado was studied. Insight was sought into the community structure and factors influencing species distribution of a vegetation type heretofore undescribed in the southern Rocky Mountains. A vegetational gradient was evaluated using detrended correspondence analysis (DCA). Four types of vegetation were subjectively defined; these same types were distinguished by the DCA. DCA further revealed marked differences in the vegetation occurring on peat hummocks versus in hollows. Species composition was related to environment using canonical correspondence analysis (CCA). Water-table depth, hummock height, shading, groundwater temperature, and conductivity were significantly correlated with species distribution, accounting for 51% of the total species variance. Univariate regression was used to examine how tree density varied with environment. The above factors, except for shading and conductivity, were also significantly correlated with tree density. It is suggested that the peat hummocks that form on this moderate fen provide an environment similar to that of an ombrotrophic bog and that these "miniature bogs" form in areas unable to support expansive bogs. Further, these hummocks provide small-scale environmental heterogeneity that exerts a strong control over species composition that would not be evident in studies based on samples of a large areal extent. Keywords: Colorado, gradient analysis, ordination, heterogeneity, peatlands, phytosociology.

Importance of hydrochory in structuring plant communities along rivers

1991 ◽  
Vol 69 (12) ◽  
pp. 2631-2633 ◽  
Author(s):  
Christer Nilsson ◽  
Maria Gardfjell ◽  
Gunnel Grelsson
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Current Velocity ◽  
Environmental Variables ◽  
Riparian Vegetation ◽  
Small Scale ◽  
Water Dispersal ◽  
Seed Deposition ◽  
Riparian Plant Communities ◽  
Riparian Plant

Using wooden cubes as experimental seed mimics we tested whether differences in seed deposition among riverbank sites predictably affect the structure of riparian vegetation. Although cube deposition was not interpretable in terms of environmental variables like current velocity, riverbank width, and substrate, it was related to species composition of the riparian vegetation. We found an excess of species with short-floating seeds among those that were most frequent in sites capturing few cubes and an excess of species with long-floating seeds among those that were most frequent in sites capturing many cubes. This result provides the first evidence that water dispersal interacting with floating time may play a role in small-scale structuring of riparian plant communities. Key words: floating time, hydrochory, riparian vegetation, river, seed mimics, seed deposition.

scholarly journals Environmental structure affects taxonomic diversity but not functional structure of understory birds in the southwestern Brazilian Amazon

2019 ◽  
Vol 49 (3) ◽  
pp. 232-241
Author(s):  
Jocieli de OLIVEIRA ◽  
Sara M. ALMEIDA ◽  
Fernando P. FLORÊNCIO ◽  
João B. PINHO ◽  
Dalci M. M. OLIVEIRA ◽  
...  
Keyword(s):  
Species Composition ◽  
Environmental Variables ◽  
Taxonomic Diversity ◽  
Brazilian Amazon ◽  
Functional Structure ◽  
Small Scale ◽  
Environmental Characteristics ◽  
Bird Assemblages ◽  
Functional Richness ◽  
Number Of Individuals

ABSTRACT Changes in environmental characteristics can affect habitat use by birds, impacting the number of individuals, number of species, and changing species composition and functional structure of assemblages. Metrics that evaluate the functional structure of biological assemblages constitute a complementary tool to the traditional taxonomic approach, because they quantify the differences between species by means of functional traits. We assessed the effect of environmental characteristics on the taxonomic diversity (species richness, species composition and number of individuals) and functional structure (functional richness, functional evenness, Rao’s functional diversity, and community-weighted mean traits) of bird assemblages in northern Mato Grosso state, in the southwestern Brazilian Amazon. We sampled birds in 32 plots. At each plot birds were captured using mist nets, and eight environmental variables were measured: canopy openness, leaf litter, elevation, number of trees in three classes of DBH, soil clay content, and distance to nearest stream. To evaluate functional structure, we measured seven morphological traits from individuals of each bird species. Habitat variables had a significant effect on taxonomic diversity. However, the general functional structure was not affected. Elevation and distance to nearest stream were the main variables driving changes in taxonomic diversity and had a minor effect on functional richness. The other metrics of functional structure were not significantly affected by the set of environmental variables. Our results suggest that the sampled bird assemblages exhibit some functional tolerance (redundancy) to small-scale environmental variation, implying certain resilience to ecosystem modification.

Small-scale vegetation mapping of large territories: perspectives of using modern remote sensing and GIS technologies, the Indian experiences

1996 ◽  
pp. 51-54 ◽  
Author(s):  
N. V. M. Unni
Keyword(s):  
Remote Sensing ◽  
Satellite Remote Sensing ◽  
Forest Cover ◽  
Human Life ◽  
Remote Sensing Data ◽  
Modern World ◽  
Small Scale ◽  
Vegetation Map ◽  
Gis Technologies ◽  
Forest Cover Mapping

The recognition of versatile importance of vegetation for the human life resulted in the emergence of vegetation science and many its applications in the modern world. Hence a vegetation map should be versatile enough to provide the basis for these applications. Thus, a vegetation map should contain not only information on vegetation types and their derivatives but also the geospheric and climatic background. While the geospheric information could be obtained, mapped and generalized directly using satellite remote sensing, a computerized Geographic Information System can integrate it with meaningful vegetation information classes for large areas. Such aft approach was developed with respect to mapping forest vegetation in India at. 1 : 100 000 (1983) and is in progress now (forest cover mapping at 1 : 250 000). Several review works reporting the experimental and operational use of satellite remote sensing data in India were published in the last years (Unni, 1991, 1992, 1994).

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.

scholarly journals Small-scale plant species distribution in snowbeds and its sensitivity to climate change

Plant Ecology ◽  
2008 ◽  
Vol 200 (1) ◽  
pp. 91-104 ◽  
Author(s):  
Christian Schöb ◽  
Peter M. Kammer ◽  
Philippe Choler ◽  
Heinz Veit
Keyword(s):  
Climate Change ◽  
Plant Species ◽  
Species Distribution ◽  
Small Scale

scholarly journals Zooplankton in seagrass and adjacent non-seagrass habitats in Tun Mustapha Park, Sabah, Malaysia

2020 ◽  
Vol 4 (1) ◽  
pp. 6-13
Author(s):  
Sing Lui Lo ◽  
Tzuen Kiat Yap ◽  
Cheng Ann Chen ◽  
Teruaki Yoshida
Keyword(s):  
Environmental Variables ◽  
Statistical Difference ◽  
Structural Complexity ◽  
Zooplankton Community ◽  
Small Scale ◽  
Zooplankton Abundance ◽  
Seagrass Bed ◽  
Seagrass Meadows ◽  
Marine Park ◽  
Study Sites

A comparison of zooplankton abundance and community in the seagrass and non-seagrass areas of Limau-limauan and Bak- Bak waters within the newly established Tun Mustapha Marine Park was made during 15-17 May 2017. Samples were collected via horizontal tow of a 140 μm plankton net. Environmental variables (temperature, salinity, DO, pH, turbidity) showed no significant differences among the study sites. However, zooplankton showed increasing abundance from non-seagrass, seagrass edge, to seagrass areas at Limau-limauan, while abundance values were comparable among the stations at Bak-bak. Overall zooplankton abundance was significantly higher at the seagrass areas relative to the non-seagrass station at Limau-limauan (p < 0.005), while no statistical difference was found at Bak-Bak (p < 0.21). Mean canopy height was 3-fold higher (p < 0.001) at Limau-limauan than Bak-Bak, suggesting the importance of seagrass bed structural complexity in habitat preference for zooplankton. Cluster analysis revealed the zooplankton community from the seagrass area at Limau-limauan was different from that at seagrass edge and non-seagrass areas, which may be attributed to the influence of seagrass meadows in forming characteristic zooplankton compositions. Marked differences in zooplankton composition and abundance even in close vicinity of sites suggest the importance of local small-scale variations in seagrass habitats in shaping the zooplankton community.

Spatial Variation of Soil Organic Matter in Gully Bed with the Seabuckthorn Flexible Dam: A Case Study of EG1 in Zhun-Ge-Er County of Inner Mongolia, China

2014 ◽  
Vol 1073-1076 ◽  
pp. 619-627
Author(s):  
Fang She Yang ◽  
Shu Zhen Su ◽  
Juan Juan Zhang ◽  
Ci Fen Bi
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Spatial Autocorrelation ◽  
Spatial Variation ◽  
Inner Mongolia ◽  
Small Scale ◽  
Obvious Effect ◽  
Small Catchment ◽  
Variation Characteristics ◽  
Random Variation

In this paper, based on geostatistics and GIS techniques, spatial variation characteristics of soil organic matter (acronym: SOM) on a small scale were analyzed and discussed in east-one-branch gully (EG1) bed with the seabuckthorn flexible dam and the contrastive gully bed (which is non-vegetated any vegetation) located in zhun-ge-er county, Erdos, inner Mongolia, which belongs to the typical Pisha Sandstone area. The results show that the seabuckthorn can significantly increase SOM in the small catchment gully bed in the Pisha sandstone area, and the mean SOM content in gully bed with the seabuckthorn flexible dam is approximate 1.75 times that in the contrastive gully. Apparent spatial variation characteristics of SOM were found in the gully with the seabuckthorn flexible dam and the contrastive gully bed, moreover, the medium spatial autocorrelation of SOM was detected in gully bed with the seabuckthorn flexible dam, and the spatial variation of SOM was together led to by the structural and random variation at 1-6.5 m range, and of which the random variation accounts for 40%. Additional, the spatial autocorrelation of SOM in the contrastive gully bed is higher, the spatial variation of SOM was dominantly brought about by the structural variation at 1-4.5 m range, and of which the random variation accounts for 37%. Furthermore, the fractal dimension values reveal that dependence of SOM of the gully bed with the seabuckthorn flexible dam on spatial is weaker than that of the contrastive gully bed. It is judged that the seabuckthorn has an obvious effect on spatial distribution patterns and heterogeneity of SOM on a small scale.

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