scholarly journals Methodological aspects in the study of species richness, diversity and homotony of grass cover

2008 ◽  
Vol 53 (No. 1) ◽  
pp. 33-41 ◽  
Author(s):  
F. Klimeš ◽  
L. Kolář ◽  
J. Květ ◽  
W. Opitz von Boberfeld ◽  
H. Laser
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Plant Species ◽  
Species Number ◽  
Regression Equations ◽  
Grass Cover ◽  
Methodological Aspects ◽  
The Relationship ◽  
Number Of Plant Species

This work proposes a new method for the assessment of species richness, diversity, and homotony in related vegetation relevés of grass swards. Hypothetical vegetation relevés with identical species number but differing constancy were generated to compare the techniques describing the species variety and diversity. By calculating these theoretical values in combination with data from real swards of Alopecuretum meadows, it has been shown that the determination of the constancy of particular species is essential for the evaluation of species diversity of grass swards. The relationship between the share of different combinations of vegetation relevés in the whole sample and corresponding total number of plant species were expressed by generating regression equations and the mid values of these curves were worked out and evaluated for individual sets of relevés; it was then possible to create homotony/heterotony indices for these sets. The indices of heterotony can be used, e.g., for expressing biotope diversity within a set of vegetation relevés from different stands.

scholarly journals Relationships between resource availability and elevation vary between metrics creating gradients of nutritional complexity

Oecologia ◽  
2021 ◽  
Vol 195 (1) ◽  
pp. 213-223
Author(s):  
Mark A. Lee ◽  
Grace Burger ◽  
Emma R. Green ◽  
Pepijn W. Kooij
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Resource Availability ◽  
Plant Biomass ◽  
Plant Species Richness ◽  
Mineral Contents ◽  
Nutritive Values ◽  
Animal Community ◽  
Nutritional Chemistry ◽  
The Relationship

AbstractPlant and animal community composition changes at higher elevations on mountains. Plant and animal species richness generally declines with elevation, but the shape of the relationship differs between taxa. There are several proposed mechanisms, including the productivity hypotheses; that declines in available plant biomass confers fewer resources to consumers, thus supporting fewer species. We investigated resource availability as we ascended three aspects of Helvellyn mountain, UK, measuring several plant nutritive metrics, plant species richness and biomass. We observed a linear decline in plant species richness as we ascended the mountain but there was a unimodal relationship between plant biomass and elevation. Generally, the highest biomass values at mid-elevations were associated with the lowest nutritive values, except mineral contents which declined with elevation. Intra-specific and inter-specific increases in nutritive values nearer the top and bottom of the mountain indicated that physiological, phenological and compositional mechanisms may have played a role. The shape of the relationship between resource availability and elevation was different depending on the metric. Many consumers actively select or avoid plants based on their nutritive values and the abundances of consumer taxa vary in their relationships with elevation. Consideration of multiple nutritive metrics and of the nutritional requirements of the consumer may provide a greater understanding of changes to plant and animal communities at higher elevations. We propose a novel hypothesis for explaining elevational diversity gradients, which warrants further study; the ‘nutritional complexity hypothesis’, where consumer species coexist due to greater variation in the nutritional chemistry of plants.

scholarly journals SPECIES DIVERSITY, UTILIZATION AND CONSERVATION IN HOME GARDENS OF SOME RESIDENTIAL AREAS, COIMBATORE, INDIA.

2015 ◽  
Vol 2 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Jamuna S ◽  
Subhasree R ◽  
Karthika K ◽  
Paulsamy S ◽  
Thenmozhi K
Keyword(s):  
Species Diversity ◽  
Plant Species ◽  
Ocimum Basilicum ◽  
Home Gardens ◽  
The Other ◽  
Home Garden ◽  
Residential Areas ◽  
Important Species ◽  
Celosia Cristata ◽  
Number Of Plant Species

The present study was aimed at documenting species composition, utilization and conservation of plant species growing in home gardens of 10 residential areas of Coimbatore city, India. Household interviews and home garden surveys revealed that all the 109 plant species included in 60 families included have someeconomic uses or with ornamental significance. Higher number of species was herbs followed by shrubs, trees, climbers, succulent herbs, vines and sub-shrubs. The families viz., Asteraceae, Apocynaceae and Acanthaceae contributed higher number of plant species than the other families to the home gardens. Thespecies namely, Celosia cristata, Chrysanthemum odoratum and Ocimum basilicum have registered 50% frequency among the home gardens sampled which indicates that these species have distributed and maintained in comparatively higher number of home gardens. The home garden species are mainly under thecategories of vegetables, fruits, ornamentals, economic important species and medicinal. These results further report revealed that homegardens satisfy various household needs like food, ornamentals, medicines, building material, religious and ceremonial uses.

scholarly journals The relationship between resource abundance and insect herbivory on islands

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256183
Author(s):  
Bora Shin ◽  
Jae-Young Lee ◽  
Nang-Hee Kim ◽  
Sei-Woong Choi
Keyword(s):  
Plant Species ◽  
Forest Cover ◽  
Food Resource ◽  
Phytophagous Insects ◽  
Feeding Guild ◽  
Resource Abundance ◽  
Variable Effect ◽  
The Relationship ◽  
External Feeding ◽  
Number Of Plant Species

We examined the relationship between resource abundance and the feeding activity of phytophagous insects on three common island plants. The aim was to investigate the correlation between phytophagous insects’ abundance and availability of food and island geography. We collected 30,835 leaves from three tree species groups (Mallotus japonicus, Prunus species, and Quercus species) on 18 islands in southwest Korea. The number of plant resources for herbivores varied: the number of leaves per shoot was the highest in Mallotus, leaf weight and the water content per leaf was significantly lower in Quercus species. External feeding was higher for Prunus and Quercus species, whereas the internal feeding type was significantly higher for Quercus species. Geography (area and distance), elevation and food resource (elevation, number of plant species, and the forest cover rate) had a variable effect on phytophagous insects feeding activities: distance and the number of plant species were more explainable to the external feeding guild. In contrast, area and forest cover were more to the internal feeding guild.

scholarly journals Superhost Plants Alter the Structure of Plant–Galling Insect Networks in Neotropical Savannas

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 369 ◽  
Author(s):  
Araújo ◽  
Moreira ◽  
Falcão ◽  
Borges ◽  
Fagundes ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Diversity ◽  
Host Plants ◽  
Plant Species Richness ◽  
Variable Number ◽  
Insect Species ◽  
Species Number ◽  
Neotropical Savannas ◽  
Galling Insects

Host plants may harbor a variable number of galling insect species, with some species being able to harbor a high diversity of these insects, being therefore called superhost plants. In the present study, we tested the hypothesis that the occurrence of superhost plant species of genus Qualea (Vochysiaceae) affects the structure of plant–galling insect ecological networks in Brazilian Cerrado. We sampled a total of 1882 plants grouped in 131 species and 43 families, of which 64 species and 31 families of host plants hosted 112 galling insect species. Our results showed that occurrence of superhosts of genus Qualea increased the linkage density of plant species, number of observed interactions, and the size of plant–galling insect networks and negatively affected the network connectance (but had no effect on the residual connectance). Although the occurrence of Qualea species did not affect the plant species richness, these superhosts increased the species richness and the number of interactions of galling insects. Our study represents a step forward in relation to previous studies that investigated the effects of plant diversity on the plant–insect networks, showing that few superhost plant species alter the structure of plant–herbivore networks, even without having a significant effect on plant diversity.

scholarly journals Species richness of alien plants in South Africa: Environmental correlates and the relationship with indigenous plant species richness

Ecoscience ◽  
2005 ◽  
Vol 12 (3) ◽  
pp. 391-402 ◽  
Author(s):  
David M. Richardson ◽  
Mathieu Rouget ◽  
Samantha J. Ralston ◽  
Richard M. Cowling ◽  
Berndt J. Van Rensburg ◽  
...  
Keyword(s):  
South Africa ◽  
Species Richness ◽  
Plant Species ◽  
Plant Species Richness ◽  
Alien Plants ◽  
Environmental Correlates ◽  
Indigenous Plant ◽  
The Relationship

scholarly journals Stability in the plant communities of the Park Grass Experiment: the relationships between species richness, soil pH and biomass variability

1994 ◽  
Vol 346 (1316) ◽  
pp. 185-193 ◽  
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Climatic Conditions ◽  
Species Number ◽  
Soil Reaction ◽  
Moisture Deficit ◽  
Rothamsted Experimental Station ◽  
Park Grass Experiment ◽  
The Relationship ◽  
Biomass Variability

The Park Grass Experiment (PGE), begun at Rothamsted Experimental Station in 1856 and still running, affords a unique opportunity to test for the influence of species number and soil reaction on biomass variability in a suite of comparable plant communities. Biomass variability was measured by calculating the coefficient of variation ( CV ) over time of annual hay yield in an eleven-year moving window. CV and species number were both strongly negatively correlated with biomass; both relations were affected by time and pH. Multiple regression of CV on species number and mean biomass for nonacidified plots in 42 years between 1862 and 1991 showed a relationship between biomass and CV which was negative in most years and significantly so in nearly three quarters of them (30/42). We are unable to tell how much of this effect is intrinsic to the statistical relation between the mean and CV of biomass. Species number was negatively correlated with CV in 29/42 years, but this was statistically significant on only three occasions. Because this relation was highly significant in the year (1991) for which we have the largest sample size (34 plots), we tentatively conclude that biomass variability may be lower in more species-rich communities, although the effect is possibly a weak one. We suggest that physiological stresses imposed by low pH may explain the greater variability of plots with acidified soil. An increase in the variability of biomass that occurred across plots with time may be due in part to acidification across the whole experiment. Three hypotheses are proposed to explain the relationship between species richness and biomass variability: (i) biomass variability on more species-rich plots is better buffered against climatic variation because species differ in their response to climatic conditions: (ii) there are fewer species on plots with greater biomass variability because species have been lost by competitive exclusion in years when biomass reaches high values; (iii) species richness and variability are both correlated with a third variable, for example soil moisture deficit within a plot. All three hypotheses are susceptible to testing within the PGE.

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