Linking ecological processes with spatial and non-spatial patterns in plant communities

Within the Platberg area and the wider Drakensberg region, the shrinking natural resources and the threat posed to biodiversity are of concern to conservation management and require an understanding of long-term ecological processes. The vegetation of Platberg was investigated as part of an ecological survey to establish Afromontane floristic links to the Drakensberg as well as for the management of natural resources. From a TWINSPAN classification, refined by the Braun-Blanquet method, four main plant communities were identified, which were subdivided into fynbos, wetland, a woody/shrub community and grassland. A classification and description of the fynbos are presented in this article.The analysis showed the fynbos divided into two communities comprising four sub-communities and seven variants. The fynbos community had an average of 28.34 species per relevé, ranging from 14 to 54 species per sample plot. Twenty-four endemic or near-endemic Drakensberg Alpine Centre (DAC) species and 22 exotic (alien-invasive) species were recorded. Numerous floristic links with the DAC, Cape flora fynbos and grassland bioregions to the north and west were also found. The description of the fynbos plant communities can serve as a basis for the formulation of management plans for the area.

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A vegetation description and floristic analyses of the springs on the Kammanassie Mountain, Western Cape

Koedoe ◽

10.4102/koedoe.v47i2.78 ◽

2004 ◽

Vol 47 (2) ◽

Cited By ~ 3

Author(s):

G. Cleaver ◽

L.R. Brown ◽

G.J. Bredenkamp

Keyword(s):

Plant Communities ◽

Western Cape ◽

Ecological Processes ◽

Mountain Catchment ◽

Habitat Factors ◽

Management Plans ◽

Twinspan Classification ◽

Geological Origin ◽

The Difference

The Kammanassie Mountain is a declared mountain catchment area and a Cape mountain zebra Equus zebra zebra population is preserved on the mountain. The high number of springs on the mountain not only provides water for the animal species but also contributes to overall ecosystem functioning. Long-term conservation of viable ecosystems requires a broader understanding of the ecological processes involved. It was therefore decided that a classification, description and mapping of the spring vegetation of the Kammanassie Mountain be undertaken. A TWINSPAN classification, refined by Braun-Blanquet procedures, revealed 11 major plant communities that could be related to geological origin. Habitat factors associated with differences in vegetation include topography, soil type and grazing. Descriptions of the plant communities include diagnostic species as well as prominent and less conspicuous species of the tree, shrub and herbaceous layers. The results also indicate a high species richness compared to similar regions and the difference between plant communities of wet and dry springs. This data is important for long-term monitoring of the spring ecosystems as well as for the compilation of management plans.

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Species Richness Interacts with Drought to Affect Litter Decomposition via its Effect on Litter Nitrogen Concentration

10.21203/rs.3.rs-495381/v1 ◽

2021 ◽

Author(s):

Jiang Wang ◽

Yuan Ge ◽

J. Hans C. Cornelissen ◽

Xiaoyan Wang ◽

Song Gao ◽

...

Keyword(s):

Species Richness ◽

Global Change ◽

Climatic Change ◽

Litter Decomposition ◽

Plant Communities ◽

Nitrogen Concentration ◽

Plant Invasions ◽

Exotic Plant ◽

Ecological Processes ◽

Litter Nitrogen

Abstract Biodiversity loss, exotic plant invasions and climatic change are currently the three major challenges to our globe and can each affect various ecological processes, including litter composition. To gain a better understanding of global change impacts on ecological processes, these three global change components need to be considered simultaneously. Here we assembled experimental plant communities with species richness levels (1, 2, 4, 8 or 16) and subjected them to drought (no, moderate or intensive drought) and invasion (invasion by the exotic annual plant Symphyotrichum subulatum or not). We collected litter of the native plant communities and let it decompose for nine months within the communities. Drought decreased litter decomposition, while the exotic plant invasion had no impact. Increasing species richness decreased litter decomposition under the mesic condition (no drought), but had little impact under moderate and intensive drought. A structural equation model showed that drought and species richness affected litter decomposition mainly via influencing litter nitrogen concentration, but not via altering the quantity and diversity of soil meso-fauna or soil physio-chemical properties. The negative impact of species diversity on litter decomposition under the mesic condition was mainly ascribed to a sampling effect, i.e. via particularly low litter nitrogen concentrations in the two dominant species. Our results indicate that species richness can interact with drought to affect litter decomposition via effect on litter nitrogen. We conclude that nitrogen-dependent litter decomposition should be a mechanism to predict integrated effects of plant diversity loss, exotic plant invasions and climatic change on litter decomposition.

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Human shoreline development and the nutrient stoichiometry of aquatic plant communities in Canadian Shield lakes

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f2012-080 ◽

2012 ◽

Vol 69 (10) ◽

pp. 1642-1650 ◽

Cited By ~ 17

Author(s):

Paul C. Frost ◽

Andrea L. Hicks

Keyword(s):

Elemental Composition ◽

Plant Communities ◽

Aquatic Plant ◽

Taxonomic Composition ◽

Individual Plant ◽

Nutrient Stoichiometry ◽

Shoreline Development ◽

Ecological Processes ◽

South Central ◽

Littoral Zones

Human activities associated with residential development potentially alter ecological processes in lake littoral zones. We determined how the nutrient stoichiometry of aquatic plant communities relates to residential density around lakes of south-central Ontario. We calculated the elemental composition of entire plant communities from multiple sites in 12 lakes using measurements of individual plant C:N:P ratios and their areal biomass. We found considerable variability in the C:N:P ratios of whole aquatic plant communities among sites and lakes, which was not accounted for by intraspecific variability in the elemental composition of aquatic plants. Instead, differences in community-level C:N:P ratios primarily resulted from high interspecific variability in the elemental composition among dominant plant taxa and variable taxonomic composition of sampled plant communities. Plant community composition differed among lakes with and without shoreline residences, and we found lower C:N and C:P ratios in communities from littoral zones in human-developed lakes. Our results thus demonstrate a link between the elemental and taxonomic composition of aquatic plant communities, which may mediate biogeochemical responses of littoral zones to development of lake shorelines.

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