Relative growth rates of two epiphytic lichens, Lobaria pulmonaria and Hypogymnia occidentalis, transplanted within and outside of Populus dripzones

Botany ◽  
2012 ◽  
Vol 90 (10) ◽  
pp. 954-965 ◽  
Author(s):  
Yngvar Gauslaa ◽  
Trevor Goward
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Picea Glauca ◽  
Canopy Cover ◽  
Tree Height ◽  
P Fertilization ◽  
Lobaria Pulmonaria ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Area Growth

Overstory Populus has been shown to facilitate establishment by cyano- and cephalolichens on conifer branches within its dripzone; though the mechanisms behind this “dripzone effect” have yet to be elucidated. Here we test the following hypotheses that throughfall from Populus: (i) elevates bark pH; (ii) increases relative growth rate in cephalolichens; and (iii) stimulates their growth through phosphorus (P) fertilization. In southern British Columbia we transplanted the cephalolichen Lobaria pulmonaria (L.) Hoffm. (promoted by dripzones) and the acidophytic chlorolichen Hypogymnia occidentalis L.H. Pike for 14 months to 26 pairs of similar-sized Picea glauca × engelmannii situated within and outside of Populus dripzones. Half of our transplants were fertilized with P. Bark pH was significantly higher on spruce branches within than outside dripzones. Relative growth rate in L. pulmonaria increased with bark pH and was slightly higher within dripzones than outside, consistent with a facilitating effect of Populus on the Lobarion community. By contrast, the addition of P decreased relative thallus area growth in L. pulmonaria and increased relative thallus area growth in H. occidentalis; though a stronger influence on growth could be attributed to variation in canopy cover and tree height. We conclude that cephalolichens in our study area are unlikely to be facilitated by P leached from Populus.

Analyzing growth in cell cultures. I. Calculating growth rates

1986 ◽  
Vol 64 (1) ◽  
pp. 233-237 ◽  
Author(s):  
Susan R. Singer
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Rate Equations ◽  
Constant Growth Rate ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Growing Cell ◽  
Absolute Growth ◽  
Plant Tissue Cultures

Growth is the major parameter used to assess novel phenotypes derived from plant tissue cultures. Any quantitative analysis of growth must have an explicit rational basis. Frequently this criterion is not met. For example, the calculation (W2 − W1)/W1(W1 = initial weight; W2 = final weight) approximates neither linear nor exponential growth. Yet, it is a common method of analysis, as is the related calculation W2/W1. When absolute growth values provide insufficient information, meaningful relative growth rate equations can be utilized. Relative growth rates should be evaluated as ln (W2/W1)/(t2 − t1) for t = time, thereby yielding a constant growth rate for exponentially growing cell lines. Linear growth (root growth, for example) can be approximated by 2(W2 − W1)/((W1 + W2)(t2 − t1)). All methods of analysis we have encountered assume that relative growth at a given instant depends on total mass. The possibility exists that growth may actually be proportional to mass raised to some power less than one. For example, growth could be limited to a thin outer shell of a spherical callus. Then the relative growth rate would equal 3(W21/3 − W11/3)/(t2 − t1). Data can be seriously distorted when inappropriate calculations are used. Such distortions are exacerbated when comparisons are made. In all cases an adequate assessment of growth kinetics for each cell line and each treatment is essential.

Effect of competition on individual white spruce production in young boreal mixedwood forests

2020 ◽  
Vol 50 (8) ◽  
pp. 726-735
Author(s):  
Sandra Carr ◽  
Guy R. Larocque ◽  
Nancy Luckai ◽  
F. Wayne Bell
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Production Efficiency ◽  
Basal Area ◽  
Tree Height ◽  
White Spruce ◽  
Structural Features ◽  
Relative Growth ◽  
Mixedwood Forests ◽  
Competition Indices

Increasing the production of wood fibre from conifer species such as white spruce (Picea glauca (Moench) Voss) is one of many challenges in the management of boreal mixedwood forests. The effects of various competition measures on relative growth and relative growth rate variables were calculated for individual white spruce subject trees. Correlation analysis was used to explore relationships with competitor structural features, including the ratio of competitor basal area to subject tree basal area (CBAS), the ratio of competitor height to subject tree height (AHCS), and the proportion of softwood (FSW). Regression analysis was used to explore relationships with three distance-dependent competition indices. The ratio of subject tree height to diameter at breast height (DBH) (HDR), crown ratio (CR), and crown relative increment rate (CRIR) were significantly correlated with CBAS and AHCS. HDR, CR, CRIR, and DBH relative growth rate were all statistically significantly related to the competition indices. Results indicated that (i) relative growth and relative growth rate measures successfully captured a range of competition, (ii) crowns of trees with larger diameters used their horizontal growing space more efficiently to produce stemwood, and (iii) the proportion of softwood contributing to competition did not appear to influence subject tree production efficiency. Growth efficiency variables have the potential to improve our understanding of boreal mixedwood dynamics.

scholarly journals GROWTH OF MANGROVE COCKLE (Anandara antiquata) CULTURED IN CAGES

2009 ◽  
Vol 34 (2) ◽  
pp. 91-96
Author(s):  
Jesaja A. Pattikawa ◽  
Elizabeth Ferdinandus
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Condition Factor ◽  
Intertidal Area ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Weight Relationship ◽  
Large Size ◽  
Length Increment

Study on growth of mangrove cockle (Anadara antiquata) was conducted in the intertidal area of Passo, Inner Ambon Bay. Three size-classes of 25 individual cockles were cultured in 1 m3 cage. Length increment data was collected every two weeks for seven periods of observation. Relative growth rate, length-weight relationship and condition factor were estimated using formula proposed by Effendie, Pauly and King, respectively. The results showed that the small size had the highest length increment and relative growth rates while the large size had the best condition factor. Length-weight relationship showed isometric growth for all categories.

Patterns of allocation and growth in aquatic Sphagnum species

1995 ◽  
Vol 73 (3) ◽  
pp. 349-359 ◽  
Author(s):  
Steven K. Rice
Keyword(s):  
Growth Rate ◽  
Chlorophyll Content ◽  
Relative Growth Rate ◽  
Aquatic Plants ◽  
Common Garden ◽  
Population Level ◽  
Light Reaction ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Photosynthetic Cells

The hypothesis that aquatic plants have greater allocation to photosynthetic tissues was tested using a common garden experiment with three pairs of ecologically contrasting Sphagnum species (S. portoricense and S. papillosum; S. trinitense and S. recurvum; S. macrophyllum var. floridanum and S. strictum). When submerged, aquatic taxa (the former in each pair) all had greater relative growth rates and greater allocation to photosynthetic tissues, as evidenced by higher whole plant chlorophyll content. The evolution of greater photosynthetic allocation appears to result from changes in two independently evolving systems: allocation to photosynthetic cells rather than nonphotosynthetic hyaline cells, and a shift in biochemical partitioning within photosynthetic cells favoring light-reaction proteins. The former was assessed by comparing photosynthetic cell volume in leaves, and the latter was estimated from chlorophyll to nitrogen ratios. The mechanism whereby greater photosynthetic allocation was achieved differed in each aquatic species. In a second experiment, variation in growth and allocation was assessed for three populations each of S. trinitense and S. recurvum. Nested analysis of variance verified that the differences between S. trinitense and S. recurvum observed in relative growth rate and chlorophyll content in the species-level test were robust given the magnitude of population-level variation. It is concluded that (i) aquatic habitats do select for features that lead to greater relative growth rate in submerged environments, (ii) relative growth rate is functionally correlated with allocation to photosynthetic tissues, (iii) allocations at the cellular and biochemical level evolve independently, and (iv) patterns of allocation represent adaptations to environmental conditions present in the aquatic environment. Key words: Sphagnum, relative growth rate, chlorophyll content, allocation, aquatic plants, adaptation.

scholarly journals Soil flood tolerance of seven genotypes of Panicum maximum Jacq.

2009 ◽  
Vol 52 (6) ◽  
pp. 1341-1348 ◽  
Author(s):  
Adriane Schio Silva ◽  
Valdemir Antônio Laura ◽  
Liana Jank
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Root Biomass ◽  
Flood Tolerance ◽  
Panicum Maximum ◽  
Above Ground Biomass ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Commercial Cultivars

The soil flood tolerance of seven genotypes of Panicum maximum Jacq. (PM11, PM34, PM40 and PM45, and the commercial cultivars Massai, Mombaça and Tanzânia) was evaluated in plants subjected to two conditions: flooded and not flooded, during a period of 14 days. Flooding significantly decreased the total and above ground biomass of PM40 and PM45. For cultivar Tanzânia, flooding decreased these two variables and also root biomass. The root, total and above ground relative growth rates were significantly reduced by flooding in cultivar Tanzânia, while in PM45 only the above ground relative growth rate was reduced. Cultivar Tanzânia showed significant differences for all variables analyzed, thus was not flood tolerant, as well as PM40 and PM45. It could be concluded that Massai, PM34, Mombaça and PM11 were the most flood tolerant genotypes.

Response of Common Ragweed (Ambrosia artemisiifolia) and Giant Ragweed (Ambrosia trifida) to Postemergence Imazethapyr

Weed Science ◽  
1996 ◽  
Vol 44 (2) ◽  
pp. 248-251 ◽  
Author(s):  
Thomas O. Ballard ◽  
Michael E. Foley ◽  
Thomas T. Bauman
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Growth Response ◽  
Ambrosia Artemisiifolia ◽  
Ambrosia Trifida ◽  
Relative Growth ◽  
Common Ragweed ◽  
Relative Growth Rates ◽  
Giant Ragweed

A study was conducted to evaluate the response of common and giant ragweed to postemergence applications of imazethapyr using relative growth rate parameters. The relative growth rate was the same for untreated common and giant ragweed through the 21 d harvest interval. Relative growth rates of treated common and giant ragweed were 50% lower than the relative growth rates of untreated ragweeds 21 d after treatment. Between 21 and 56 d after treatment, the relative growth rate of common ragweed declined an additional 13%, while the relative growth rate of giant ragweed declined an additional 38%. The sharp continued decline in the relative growth rate of giant ragweed indicated plant death. The moderation and slight increase in the relative growth rate of common ragweed between 21 and 56 d corresponded with the initiation of lateral axillary buds and the regeneration of plant growth. Relative growth rate parameters identified differences in the response of common and giant ragweed to imazethapyr as early as 21 d after treatment. Relative growth rate demonstrated utility by objectively measuring differences in the growth response of these two weeds that are moderately susceptible to imazethapyr under laboratory conditions.

scholarly journals Uptake and Transport of Ions in Barley Seedlings III. Correlation Between Transport to the Shoot and Relative Growth Rate

1972 ◽  
Vol 25 (5) ◽  
pp. 905 ◽  
Author(s):  
MG Pitman
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Potassium Transport ◽  
Culture Solution ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Transport Of Ions ◽  
Total Potassium ◽  
Uptake And Transport

Determinations of potassium transport are described for plants growing at varied relative growth rates. These determinations were based on differences in total potassium content of the shoot over a 3.day period for plants growing on culture solution. It is shown that rate of transport from root to shoot is correlated with relative growth rate. The concentration of potassium in the shoot was independent of ratio of root to shoot, and little affected by relative growth rate (potassium was the only available univalent cation).

scholarly journals Ghrelin effects on the activities of digestive enzymes and growth of Lymantria dispar L.

2012 ◽  
Vol 64 (2) ◽  
pp. 497-502 ◽  
Author(s):  
Vesna Peric-Mataruga ◽  
Branka Janac ◽  
Milena Vlahovic ◽  
Marija Mrdakovic ◽  
Larisa Ilijin ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Lymantria Dispar ◽  
Endocrine Cells ◽  
Digestive Enzyme ◽  
Physiological Saline ◽  
Repeated Administration ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Simple Model System

Ghrelin, along with several other hormones, has significant effects on appetite and growth in humans and animals. The aim of our study was to examine changes in relative growth rates, ?- and ?-glucosidase activities and endocrine cell size in the midgut of 4th instar caterpillars of the pest insect Lymantria dispar L. after ghrelin treatment. Four subpicomolar injections of ghrelin (0.3 pmol) or physiological saline were applied every 24 h to two separate groups of fifteen caterpillars. Repeated administration of ghrelin in subpicomolar doses elevated the relative growth rate, induced ?- and ?-glucosidase activities and increased the size of endocrine cells. The results are the first data about ghrelin effects on relative growth rate, digestive enzyme activities and midgut endocrine cells in insects. This information supports the use of this relatively simple model system in future studies of mechanisms underlying digestion in complex organisms.

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