Data from: A lognormal distribution of the lengths of terminal twigs on self-similar branches of elm trees

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Dynamic Scaling in the Growth of a Non-Branching Plant, <em>Cardiocrinum cordatum</em>

<div><p>We investigated whole-plant leaf area in relation to ontogenetic variation in leaf-size for a forest perennial herb, <em>Cardiocrinum cordatum</em>. The 200-fold ontogenetic variability in <em>C. cordatum</em> leaf area followed a power-law dependence on total leaf number, a measure of developmental stage. When we normalized for plant size, the function describing the size of single leaves along the stem was similar among different-sized plants, implying that the different-sized canopies observed at different times in the growth trajectory were fundamentally similar to each other. We conclude that the growth trajectory of a population of <em>C. cordatum</em> plant leaves obeyed a dynamic scaling law, the first reported for a growth trajectory at the whole-plant level.</p> </div

The normalized intra-plant leaf size distribution.

<p>Each symbol represents the relationship between the normalized position (relative number of leaves counted from the bottom to top of the stem, where 0 =  bottom, 0.5 =  middle and 1.0 =  top of the stem) and the normalized leaf area (area of an individual leaf divided by the averaged leaf area for the plant) of each leaf (<i>n</i> = 208). Each series shows an entire set of leaves for each plant (<i>n</i> = 29). The bold curve represents the fitted curve estimated by using the <i>gam</i> function in the <i>mgcv</i> package of R <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045317#pone.0045317-Wood1" target="_blank">[29]</a> (<i>r</i>² = 0.792).</p

Similarity among individual leaves.

<p>Each open circle indicates one harvested leaf (<i>n</i> = 51). The solid line shows the ordinary least-squares regression, which was forced through the origin: Leaf area (cm²) = 0.717 (length × width) (<i>r</i>² = 0.997, <i>n</i> = 51, <i>p</i><0.01).</p

Log-log relationship between whole-plant leaf area and total leaf number.

<p>Each open circle represents one individual plant. The solid line shows the standardized major axis regression (<i>r</i>² = 0.93, <i>n</i> = 29).</p

Electronic Supplementary Material from A lognormal distribution of the lengths of terminal twigs on self-similar branches of elm trees

Tables S1 and S

The relationships between substrate-quality dissimilarity and dissimilarity of decomposition activity (a) and microbial community composition (b).

<p>Substrate-quality dissimilarity is calculated as the difference between 2 substrates, whereas activity and community dissimilarity are calculated as the Euclidean distance between data matrices of activity and community composition, respectively. Black, red, and light-blue filled circles indicate the mean values of the coexisting, bacterial, and fungal communities, respectively. Grey circles indicate individual values. Black, red and light-blue solid lines indicate regression lines of the coexisting, bacterial, and fungal communities, respectively. Note that the points are slightly adjusted in the x-axis direction to distinguish the values of different microbial groups. Statistical results are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0080320#pone-0080320-t003" target="_blank">Table 3</a>. Bars indicate standard errors of the mean.</p

A Coexisting Fungal-Bacterial Community Stabilizes Soil Decomposition Activity in a Microcosm Experiment

<div><p>How diversity influences the stability of a community function is a major question in ecology. However, only limited empirical investigations of the diversity–stability relationship in soil microbial communities have been undertaken, despite the fundamental role of microbial communities in driving carbon and nutrient cycling in terrestrial ecosystems. In this study, we conducted a microcosm experiment to investigate the relationship between microbial diversity and stability of soil decomposition activities against changes in decomposition substrate quality by manipulating microbial community using selective biocides. We found that soil respiration rates and degradation enzyme activities by a coexisting fungal and bacterial community (a taxonomically diverse community) are more stable against changes in substrate quality (plant leaf materials) than those of a fungi-dominated or a bacteria-dominated community (less diverse community). Flexible changes in the microbial community composition and/or physiological state in the coexisting community against changes in substrate quality, as inferred by the soil lipid profile, may be the mechanism underlying this positive diversity–stability relationship. Our experiment demonstrated that the previously found positive diversity–stability relationship could also be valid in the soil microbial community. Our results also imply that the functional/taxonomic diversity and community ecology of soil microbes should be incorporated into the context of climate–ecosystem feedbacks. Changes in substrate quality, which could be induced by climate change, have impacts on decomposition process and carbon dioxide emission from soils, but such impacts may be attenuated by the functional diversity of soil microbial communities.</p></div

Ontogenetic growth trajectory of <i>C</i>. <i>cordatum</i> rosettes.

<p>The photographs show representative <i>C</i>. <i>cordatum</i> plants on 10 May 2010. Red scale bars superimposed on each photograph indicate a distance of 5 cm on each leaf. Leaf punch holes and ink markings used for other experiments appear on some of the leaves (photographs by K. Koyama, taken on 10 May 2010).</p

Results of regression analysis between dissimilarities in decomposition activity, lipid profile and substrate quality.

<p>Values within parentheses indicate the 95% confidence intervals estimated by 999 bootstraps. The “ecodist” package of R was used to conduct these analyses. ^†Corresponding to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0080320#pone-0080320-g002" target="_blank">Fig. 2a</a>. ^††Corresponding to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0080320#pone-0080320-g002" target="_blank">Fig. 2b</a>.</p