Some aspects of the vegetation ecology of the Little Qualicum River estuary, British Columbia

1982 ◽  
Vol 60 (8) ◽  
pp. 1447-1460 ◽  
Author(s):  
Neil K. Dawe ◽  
Eric R. White
Keyword(s):  
Plant Communities ◽  
Soil Type ◽  
Vascular Plants ◽  
Vascular Plant ◽  
River Estuary ◽  
Dry Weight ◽  
Factors Affecting ◽  
Juncus Balticus ◽  
Major Factors ◽  
Channel Edge

Nine vascular plant communities were determined and mapped from data gathered on the Little Qualicum River estuary, Vancouver Island, B.C., during the period May to September 1978. Those communities comprised 51 species of vascular plants; however, only 10 species occurred with constancies of 20% or greater. Carex lyngbyei, Potentilla pacifica, Juncus balticus, and Agrostis sp. dominated vegetation. Major factors affecting the distribution of the vegetation within the estuary appeared to be site elevation, soil type and texture, and inundating water salinity. Aerial production was dominated by that of the Carex – channel edge community which had a peak aboveground biomass of 1693 g dry weight∙m−2.

Some aspects of the vegetation ecology of the Nanoose–Bonell estuary, Vancouver Island, British Columbia

1986 ◽  
Vol 64 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Neil K. Dawe ◽  
Eric R. White
Keyword(s):  
British Columbia ◽  
Vascular Plants ◽  
Dry Weight ◽  
Vancouver Island ◽  
Distichlis Spicata ◽  
Factors Affecting ◽  
Salicornia Virginica ◽  
Major Factors ◽  
Triglochin Maritimum ◽  
Water Elevation

A study of the vegetation of the Nanoose – Bonell salt marsh, Vancouver Island, British Columbia, was conducted during the period of May – September 1978. A total of 49 species of vascular plants was identified, 10 of which dominated the flora of the estuarine marsh. Six of those dominant species (Distichlis spicata, Glaux maritima, Salicornia virginica, Triglochin maritimum, Plantago maritima, and Atriplex patula) are tolerant of high salinities. Eight plant communities were identified and mapped within the study area. Aerial biomass was dominated by that of the Carex – channel edge community with a peak aboveground biomass of 1259 g dry weight/m2. Major factors affecting the occurrence and distribution of species within the marsh were salinity of the inundating water, elevation of the marsh platform, and soil texture.

Plant community and diversity change due to localized permafrost dynamics in bogs of western Canada

2001 ◽  
Vol 79 (8) ◽  
pp. 983-993 ◽  
Author(s):  
David W Beilman
Keyword(s):  
Multidimensional Scaling ◽  
Plant Community ◽  
Plant Communities ◽  
Vascular Plants ◽  
Species Turnover ◽  
Vascular Plant ◽  
Western Canada ◽  
Permafrost Degradation ◽  
Southern Limit ◽  
Metric Multidimensional Scaling

Localized permafrost formation and melt at the southern limit of permafrost has a large effect on boreal bog plant community structure and diversity in continental western Canada (Alberta, Saskatchewan, and Manitoba). Non-metric multidimensional scaling ordinations show that non-permafrost-affected bogs, areas currently underlain by permafrost (frost mounds), and areas of permafrost degradation (internal lawns) have distinct plant communities. Bryophytes respond more strongly than vascular plants to lengthened environmental gradients in the bogs studied. Seventy-two vascular plant and bryophyte species were found, with mean alpha diversity (species richness) similar in bogs and internal lawns (22.6 and 22.1) and lowest on frost mounds (15.6). Beta diversity (species turnover between landforms) is greater for bryophytes (4.22) than vascular plants (2.54). Comparisons within internal lawns show highly variable height above water table, community composition, and species diversity in wet communities and reduced variability as peat accumulates and converges on dry surfaces dominated by Sphagnum fuscum (Schimp.) Klinggr. Overall, localized permafrost dynamics increase bog plant diversity by 47% by introduction of unique dry, shaded (frost mound) and wet, open (internal lawn) conditions absent from non-permafrost-affected bogs, making localized permafrost bogs one of the most bryologically diverse peatland types in western Canada.Key words: peatlands, bryophytes, plant communities, non-metric multidimensional scaling ordination, permafrost, climate change.

Factors affecting the early growth of Leucaena leucocephala

1997 ◽  
Vol 37 (1) ◽  
pp. 27 ◽  
Author(s):  
N.J Brandon ◽  
H.M Shelton
Keyword(s):  
Arbuscular Mycorrhiza ◽  
Plant Height ◽  
Leucaena Leucocephala ◽  
Field Experiments ◽  
Dry Weight ◽  
Early Growth ◽  
The Other ◽  
Factors Affecting ◽  
Height Increase ◽  
Major Factors

Summary. Slow establishment has been identified as a major limitation to the more widespread adoption of the fodder tree Leucaena leucocephala in Queensland. Field experiments were conducted at Mt Cotton, Gayndah and Theodore in south-east Queensland during the 1987–88 summer to identify the major factors limiting first year yield of leucaena. Treatments at each site included irrigation (applied at sowing only, or at intervals throughout the trial), and rates of phosphorus (P), nitrogen (N) and lime. Attack by psyllid insects, weed competition and defoliation by wildlife were noted and minimised where possible. Soil moisture appeared to be the major limitation to plant growth at the inland sites of Theodore and Gayndah where post-establishment irrigation increased final dry weight by 250%. Waterlogging reduced plant height increase at the low lying Mt Cotton site following higher than normal rainfall. Increase in plant height at the other sites stopped when night temperatures fell below 15°C. Application of P at 75–1200 kg/ha tripled final dry weight of leucaena at Mt Cotton (5 mg/kg bicarbonate-extractable P) but had no effect at Theodore (10 mg P/kg) or Gayndah (35 mg P/kg). Larger than normal responses to P during early growth may be due to slow colonisation of the roots by arbuscular mycorrhiza. Application of N (200 kg N/ha) increased dry weight of Rhizobium-inoculated leucaena by 27% at Theodore but had little or no effect at the other sites. Application of lime had no significant effects on plant height or dry weight of leucaena at Mt Cotton despite the soil being slightly acidic (pH 5.9 in 1 : 5 H2 O suspension). Further work on the role of colonisation by arbuscular mycorrhiza fungi in determining uptake of P by leucaena is warranted in view of the large response to very high rates of P in young seedlings at Mt Cotton.

Vascular plant communities of a polar oasis at Alexandra Fiord (79° N), Ellesmere Island, Canada

1989 ◽  
Vol 67 (4) ◽  
pp. 1126-1136 ◽  
Author(s):  
M. Muc ◽  
B. Freedman ◽  
J. Svoboda
Keyword(s):  
Cluster Analysis ◽  
Plant Species ◽  
Plant Community ◽  
Plant Communities ◽  
Vascular Plants ◽  
Vascular Plant ◽  
Detrended Correspondence Analysis ◽  
High Arctic ◽  
Ellesmere Island ◽  
Community Types

A cluster analysis was used to apportion 136 stands in a High Arctic lowland among six vascular plant community types. These communities are described on the basis of the average prominence values of vascular species and the total cover of macroalgae, bryophytes, lichens, and vascular plants within the designated clusters of stands. The relationships among the community types was explored by a detrended correspondence analysis. The ordination of stands showed considerable floristic overlap among the most widespread plant communities on the lowland. This largely reflects the microtopographic heterogeneity of the sites, the relatively depauperate flora of the High Arctic, and the considerable ecological amplitude of the most prominent vascular plant species.

Alpine lichen-dominated communities in Alberta and the Yukon

1980 ◽  
Vol 58 (20) ◽  
pp. 2148-2170 ◽  
Author(s):  
Marianne G. See ◽  
L. C. Bliss
Keyword(s):  
Plant Communities ◽  
Vascular Plants ◽  
Regional Differences ◽  
Vascular Plant ◽  
Floristic Composition ◽  
Yukon Territory ◽  
Strongly Correlated ◽  
Reciprocal Averaging ◽  
Floristic Similarity ◽  
North Central

Alpine lichen-dominated vegetation is described with emphasis upon floristic composition, quantitative structure, and distribution of lichen communities. Macrolichens and vascular plants were quantitatively sampled using stratified random quadrats (10 cm × 40 cm) in 40 stands (30 m × 5 m) in west-central Alberta and north central Yukon Territory. Comparable acid and basic substrates, and glaciated and unglaciated sites were sampled in each region. Bray-Curtis and reciprocal averaging ordinations were used to analyze vegetation data. For both macrolichens and vascular plants, floristic similarity is greater within each region than on equivalent substrates in different regions. Three alpine macrolichen communities are described in each region which exhibit pronounced regional differences. Cetraria tilesii and Thamnolia subuliformis characterize driest sites in both regions, while Cetraria cucullata indicates mesic habitats. Cladonia spp. dominate acidic Yukon sites; Stereocaulon alpinum and Peltigera aphthosa characterize equivalent Alberta habitats. Vascular plant communities are dominated by Dryas integrifolia and D. octopetala in Alberta and Yukon areas, respectively, with dwarf willow and heath in acidic, mesic sites. Distribution of alpine communities of macrolichens and corresponding vascular plants is more strongly correlated with substate pH and moisture, than with glaciation history. Comparison with other northern studies suggests that these macrolichen communities may be found throughout the Canadian Cordillera where equivalent habitats are present.

scholarly journals Different temporal trends in vascular plant and bryophytes communities along elevational gradients over four decades of warming

2020 ◽  
Author(s):  
Antoine Becker-Scarpitta ◽  
Diane Auberson-Lavoie ◽  
Mark Vellend
Keyword(s):  
Plant Communities ◽  
Vascular Plants ◽  
Environmental Changes ◽  
Vascular Plant ◽  
Elevation Gradient ◽  
Temporal Trends ◽  
Community Change ◽  
Ecosystem Functions ◽  
Ecological Communities

Abstract1: Despite many studies showing biodiversity responses to warming, the generality of such responses across taxa remains unclear. Very few studies have tested for evidence of bryophyte community responses to warming, despite the fact that bryophytes are major contributors to diversity in many ecosystems, playing a central role in ecosystem functions. Understanding variation among taxa in their responses to warming is crucial for identifying priorities in conservation.2: We report an empirical study comparing long-term change of bryophyte and vascular plant communities in two sites with contrasting long-term warming trends. To assess long-term responses of ecological communities to warming, we used “legacy” botanical records as a baseline for comparison with contemporary resurveys.We hypothesized that ecological changes would be greater in sites with a stronger warming trends, and that vascular plant communities would be more sensitive than bryophyte communities to climate warming. For each taxon in each site, we quantified the magnitude of changes in species’ distributions along the elevation gradient, species richness, and community composition.3: Temporal changes in vascular plant communities were consistent with the warming hypothesis, but this was not the case for bryophytes. We also did not find clear support for the hypothesis that vascular plants would show greater sensitivity than bryophytes to warming, with results depending on the metric of community change. As predicted for sites with a strong warming trend, we found a significant upward shift in the distributions of vascular plants but not bryophytes.Synthesis: Our results are in accordance with recent literature showing that local diversity can remain unchanged despite strong changes in composition. Regardless of whether one taxon is systematically more or less sensitive to environmental change than another, our results suggest that vascular plants cannot be used as a surrogate for bryophytes in terms of predicting the nature and magnitude of responses to warming. In sites that experienced the same environmental changes, we found that communities of bryophytes and vascular plants did not predictably change in the same ways. Thus, to assess overall biodiversity responses to global change, data from different taxonomical groups and community properties need to be synthesized.

The vegetation and its environments in Maine peatlands

1997 ◽  
Vol 75 (10) ◽  
pp. 1785-1805 ◽  
Author(s):  
Dennis S. Anderson ◽  
Ronald B. Davis
Keyword(s):  
Pore Water ◽  
Plant Communities ◽  
Vascular Plants ◽  
Vascular Plant ◽  
Species Distributions ◽  
Species Variation ◽  
Forward Selection ◽  
Multivariate Statistical ◽  
Peat Pore Water ◽  
Minimum Number

This study is based on relevés from 96 peatlands representing the typologic, environmental, and geographic variation of Maine peatlands, and on peat pore-water chemistry at a representative set of 51 of these peatlands. We give optima and tolerances of pH, Ca, P, NO3-N, NH4-N, and influence of upper on lower vegetational strata for the 73 most common vascular plant species, excluding sedges, which are presented elsewhere. The program TWINSPAN differentiated 30 plant communities. Environments of the first seven TWINSPAN divisions differed largely by Ca, pH, P, NH4, Fe, microrelief, substrate depth, degree of humification, and climate. A canonical correspondence analysis (CCA) with forward selection entered pH, P, Na, Fe, Ca, Mg, and percent H2O as the minimum number of variables which best explains species variation. A CCA of the lower strata vascular plants demonstrated the importance of the upper strata (percent overstory) on species' distributions. Gradients of pH–alkalinity and percent overstory are primary in determining Maine's peatland vegetation. Other important gradients are percent H2O in upper peat, concentrations of lithic elements (P, Fe, Mn, Al, and Si) in pore water, and climate. Although these gradients partially covary, some of the variation in species' distributions can be attributed to independent aspects of individual gradients. Species richness across the range of peatland types is related to pH–alkalinity for vascular plants, and to percent H2O, microrelief, and percent overstory for bryophytes. Key words: plant communities, Maine, multivariate statistical analysis, peatlands, mires, vegetation.

scholarly journals Different temporal trends in vascular plant and bryophyte communities along elevational gradients over four decades of warming

2021 ◽  
Author(s):  
Antoine Becker Scarpitta ◽  
Diane Auberson Lavoie ◽  
Raphael Aussenac ◽  
Mark Vellend
Keyword(s):  
Plant Communities ◽  
Vascular Plants ◽  
Vascular Plant ◽  
Elevation Gradient ◽  
Temporal Trends ◽  
Species Distributions ◽  
Warming Trend ◽  
Local Diversity ◽  
Taxonomic Groups

Despite many studies showing biodiversity responses to warming, the generality of such responses across taxonomic groups remains unclear. Very few studies have tested for evidence of bryophyte community responses to warming, even though bryophytes are major contributors to diversity and functioning in many ecosystems. Here we report an empirical study comparing long-term change of bryophyte and vascular plant communities in two sites with contrasting long-term warming trends, using “legacy” botanical records as a baseline for comparison with contemporary resurveys. We hypothesized that ecological changes would be greater in sites with a stronger warming trend, and that vascular plant communities, with narrower climatic niches, would be more sensitive than bryophyte communities to climate warming. For each taxonomic group in each site, we quantified the magnitude of changes in species’ distributions along the elevation gradient, species richness, and community composition. We found contrasted temporal changes in bryophyte vs. vascular plant communities, which only partially supported the warming hypothesis. In the area with a stronger warming trend, we found a significant increase of local diversity and beta-diversity for vascular plants, but not for bryophytes. Presence absence data did not provide sufficient power to detect elevational shifts in species distributions. The patterns observed for bryophytes are in accordance with recent literature showing that local diversity can remain unchanged despite strong changes in composition. Regardless of whether one taxon is systematically more or less sensitive to environmental change than another, our results suggest that vascular plants cannot be used as a surrogate for bryophytes in terms of predicting the nature and magnitude of responses to warming. Thus, to assess overall biodiversity responses to global change, abundance data from different taxonomic groups and different community properties need to be synthesized.

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