scholarly journals Species Composition Changes in a Rooftop Grass and Wildflower Meadow: Implications for Designing Successful Mixtures

2004 ◽  
Vol 5 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Daniel W. Dewey ◽  
Paul G. Johnson ◽  
Roger K. Kjelgren
Keyword(s):  
Species Composition ◽  
Composition Changes

scholarly journals Functional Composition Changes of a Subtropical Monsoon Evergreen Broad-Leaved Forest Under Environmental Change

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 191
Author(s):  
Shun Zou ◽  
Qianmei Zhang ◽  
Guoyi Zhou ◽  
Shizhong Liu ◽  
Guowei Chu ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Drought Tolerance ◽  
Species Composition ◽  
Environmental Change ◽  
Subtropical Forest ◽  
Functional Composition ◽  
Composition Change ◽  
Environment Change ◽  
Soil Dryness ◽  
Composition Changes

Long-term studies have revealed that forest species composition was shifting under environment change and disturbance induced by loss of large trees. Yet, few studies explicitly analyzed their impacts on composition concurrently. To learn more about impacts of environment change and disturbance on driving forest community, we investigated shifts in functional composition over past 24 years in an old-growth subtropical forest in southern China. We analyzed nine traits that are mainly related to leaf nutrients, photosynthetic capacity, hydraulic conductivity, and drought tolerance of plants and examined hypotheses: (1) The functional composition change over time was directional instead of random fluctuation, (2) drought-tolerant species increased their abundance under soil dryness, (3) both environmental change and disturbance related to changes of functional composition significantly, and (4) initial trait values of quadrats strongly influenced their subsequent change rates in quadrat level (10 × 10 m). We found that species composition had shifted to favor species with high leaf nutrient content, high photosynthesis rate, high hydraulic conductivity, low water-use efficiency, and high drought tolerance traits, which was due to soil dryness and disturbance. These two factors explained 47–58% of quadrats’ trait value changes together. Considering rapidly increasing stem density, this pattern may indicate ecological processes of which disturbance provided numerous recruits of resource-acquisition strategy species and soil dryness conducted a selecting effect on shaping composition in the forest. Additionally, quadrats with initial trait values at the far end of change direction shifted faster in three traits, which also indicated that functional composition changes in quadrats were directional and homogenized. Our results implied that environment change and accompanied disturbance events possibly drove species composition change along a different trajectory in the subtropical forest that experienced high climatic variability.

scholarly journals Dynamics of stand composition changes in grass and grass-clover stands and relations between dominant species

2011 ◽  
Vol 49 (No. 3) ◽  
pp. 119-125
Author(s):  
P. Matušinsky ◽  
F. Hrabě
Keyword(s):  
Species Composition ◽  
Dominant Species ◽  
Grass Species ◽  
Individual Species ◽  
Yield Parameters ◽  
Method Of Determination ◽  
Subsequent Comparison ◽  
Composition Changes ◽  
Good Agreement

Changes in the species composition of temporary grass and grass-clover crops stands were studied in 1994–2000. The assessment consisted in determination of the dominance of individual species, measurement of their aboveground biomass weight and subsequent comparison of detected values. The measurements were evaluated by the method of determination of distance between vectors of stand composition and by the subsequent standardization. Resulting values are in a good agreement with the hither to knowledge and confirm that more favourable yield parameters are achieved within 30–60% of total changeability. Changes of species composition and stand changeability are at their initial stages of succession given by external changes mainly contributed to by the group of clumpy grass species and by internal changes within the group of pod-bearing plants.

Monitoring protozoa and metazoa biofilm communities for assessing wastewater quality impact and reactor up-scaling effects

2000 ◽  
Vol 41 (4-5) ◽  
pp. 309-316 ◽  
Author(s):  
J. Fried ◽  
G. Mayr ◽  
H. Berger ◽  
W. Traunspurger ◽  
R. Psenner ◽  
...  
Keyword(s):  
Species Composition ◽  
Large Scale ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Plant Performance ◽  
Scaling Effects ◽  
Wastewater Quality ◽  
Biofilm Structure ◽  
Composition Changes ◽  
Up Scaling

The succession of biofilm communities with special emphasis on ciliates, rotifers, and nematodes was monitored for half a year and compared to different operating conditions in order to evaluate plant performance and effect of up-scaling lab scale to large scale reactors. Ciliates and metazoa are able to rapidly change their communities as a reaction to changed plant operating conditions as has been proven true by comparing lab scale and pilot scale reactors. Even slight operational changes are causing major shifts in biofilm communities. Nematodes and rotifers in lab scale and large scale reactors seem to be in competition with peritrich ciliates. In both lab scale and pilot scale systems ciliates of the subclass Peritrichia proved to be dominant and thus to play an important role in both the species composition of the biofilm biocenosis and biofilm structure. Interpretation of biocenosis composition changes for large scale reactors is much more complex than for lab scale reactors. This conflicts with up-scaling of lab scale results to full scale reactors.

scholarly journals Coral Resilience at Malauka`a Fringing Reef, Kāneʻohe Bay, Oʻahu after 18 years

2019 ◽  
Vol 7 (9) ◽  
pp. 311 ◽  
Author(s):  
Barnhill ◽  
Bahr
Keyword(s):  
Climate Change ◽  
Species Composition ◽  
Coral Species ◽  
Coral Cover ◽  
Kappaphycus Alvarezii ◽  
Percent Cover ◽  
Fringing Reef ◽  
Porites Compressa ◽  
Original Survey ◽  
Composition Changes

Globally, coral reefs are under threat from climate change and increasingly frequent bleaching events. However, corals in Kāneʻohe Bay, Hawaiʻi have demonstrated the ability to acclimatize and resist increasing temperatures. Benthic cover (i.e., coral, algae, other) was compared over an 18 year period (2000 vs. 2018) to estimate species composition changes. Despite a climate change induced 0.96°C temperature increase and two major bleaching events within the 18-year period, the fringing reef saw no significant change in total coral cover (%) or relative coral species composition in the two dominant reef-building corals, Porites compressa and Montipora capitata. However, the loss of two coral species (Pocillopora meandrina and Porites lobata) and the addition of one new coral species (Leptastrea purpurea) between surveys indicates that while the fringing reef remains intact, a shift in species composition has occurred. While total non-coral substrate cover (%) increased from 2000 to 2018, two species of algae (Gracilaria salicornia and Kappaphycus alvarezii) present in the original survey were absent in 2018. The previously dominant algae Dictyosphaeria spp. significantly decreased in percent cover between surveys. The survival of the studied fringing reef indicates resilience and suggests these Hawaiian corals are capable of acclimatization to climate change and bleaching events.

Faunal provinces in Canada as exemplified by mammals and birds: a mathematical consideration

1972 ◽  
Vol 50 (8) ◽  
pp. 1087-1104 ◽  
Author(s):  
Gary W. Kaiser ◽  
Leonard P. Lefkovitch ◽  
Henry F. Howden
Keyword(s):  
Species Composition ◽  
Species Density ◽  
Passerine Birds ◽  
Rates Of Change ◽  
Mathematical Techniques ◽  
Taxonomic Groups ◽  
Composition Changes ◽  
Sharp Breaks

Although different regions have a characteristic fauna, mathematical techniques based on rates of change in composition, changes in species density, and similarity of composition do not give unequivocal definitions of faunal provinces. There is some concordance between species consistency of large taxonomic groups (mammals, passerine, and non-passerine birds) and the ecological pressures exerted on the groups. Changes in species composition are characterized by gradual shifts over large zones of transition and not by sharp breaks between close homogeneous areas, so that no provinces or divisions are clearly defined.

scholarly journals MONITORING OF ATMOSPHERIC AND SOIL WATER COMPOSITION IN FOREST ECOSYSTEMS: MILESTONES AND OUTLOOK

2021 ◽  
Vol 1 (4) ◽  
pp. 1-25
Author(s):  
V.V. Ershov ◽  
Keyword(s):  
Chemical Composition ◽  
Species Composition ◽  
Forest Ecosystems ◽  
Atmospheric Fallout ◽  
Water Composition ◽  
Long Term Trends ◽  
Industrial Regions ◽  
Composition Changes ◽  
Lysimetric Waters

The article provides an overview of Russian and foreign studies on assessment of the composition of atmospheric fallout and soil waters in forest ecosystems. The conclusion was made that little attention is given to the transformation of precipitation chemical composition by forest ecosystems, taking into account the influence of the species composition of the stand and the mosaic structure of the biogeocenosis (areas below the crowns, between the crowns, and open sites). European studies usually look at long-term development of the composition of atmospheric fallout and lysimetric waters, detecting long-term trends in composition changes of atmospheric and soil waters and identifying the factors driving these changes. In Russia, no such long-term (lasting for more than 10 years) continuous observations on the effect of man-made pollution on the composition and properties of atmospheric and soil waters were carried out. This task is very relevant for Russia and, especially, for its industrial regions.

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