Maia Mistral's research while affiliated with University of Otago and other places

Publications (3)

Article
Full-text available
Vegetation texture, describing plant communities by the range of characters present in them, can describe functional variation more effectively than using the identities of the species. We ask whether spatial trends, as seen in spatial autocorrelation (SAc), are stronger in vegetation texture. We also ask in what environment SAc is stronger, whethe...
Article
Full-text available
A major gap in our knowledge of plant communities is how much of their volume is occupied by plant material (stem, leaf or reproductive structure). This is basic knowledge and may be crucial for the concept of competition for space. We sampled two grassland communities and two shrublands in both Italy and New Zealand. The height of the canopy was m...
Article
Four sites were sampled to determine spatial autocorrelation in vegetation at the community level. All were in western New Zealand, but on different substrates and of different physiognomy: a terrace forest, a floodplain forest, a mire and the middle of a logging road. In ‘dissimograms’the four communities all showed steady increases in dissimilari...

Citations

... Dissimilarities (Jaccard) in species composition were identified between all seven quadrats in each transect in each strip type (unseeded and seeded). To fit a relationship between quadrat distance and Jaccard dissimilarities, we used a Gompertz asymptotic equation (Mistral et al. 2000). From the fitted curves, we identified the nugget (the y-intercept): conceptually, the dissimilarity at zero distance between quadrats and the measure of the amount of randomness in a community (Brownstein et al. 2012). ...
... Nevertheless, cover estimates fail to record specimens, which are masked under canopy leaves, if stratification is omitted. On the other hand, good correlation of estimated biovolume and plant biomass were observed by Usò et al. (1997) at species level and to some extent by Chiarucci et al. (2002) at community level. The same relation seems to be also true for this study, as high correlation (r>0.85) between estimated biovolume and dry biomass was established for the five woody species Quercus ilex, Pistacia lentiscus, Phillyrea spp., Erica multiflora and Rosmarinus officinalis (Campana 2006). ...
... To do so, we decomposed the total Euclidian distance between two sites into elevational distance (the variable to be tested) and the remaining distance (considered as potential spatial autocorrelation). We calculated this remaining distance by applying the Pythagorean theorem with elevation as one leg of a hypothetical triangle and the total distance as the hypothenuse 49 , and used it as fixed factor in the above explained model. Visual inspection of residual plots did not reveal any obvious deviations from homoscedasticity or normality. ...