Size matters: point pattern analysis biases the estimation of spatial properties of stomata distribution.
Stomata distribution is an example of biological patterning. Formal methods used to study stomata patterning are generally based on point-pattern analysis, which assumes that stomata are points and ignores the constraints imposed by size on the placement of neighbors. The inclusion of size in the analysis requires the use of a null model based on finite-size object geometry. In this study, we compare the results obtained by analyzing samples from several species using point and disc null models. The results show that depending on the null model used, there was a 20% reduction in the number of samples classified as uniform; these results suggest that stomata patterning is not as general as currently reported. Some samples changed drastically from being classified as uniform to being classified as clustered. In samples of Arabidopsis thaliana, only the disc model identified clustering at high densities of stomata. This reinforces the importance of selecting an appropriate null model to avoid incorrect inferences about underlying biological mechanisms. Based on the results gathered here, we encourage researchers to abandon point-pattern analysis when studying stomata patterning; more realistic conclusions can be drawn from finite-size object analysis.
Laboratorio Biología de Plantas, Departamento de Silvicultura y Conservación de la Naturaleza, Universidad de Chile, Av. Santa Rosa 11315, La Pintana, Santiago, Chile.
Paulette I
PI
Naulin
Laboratorio Biología de Plantas, Departamento de Silvicultura y Conservación de la Naturaleza, Universidad de Chile, Av. Santa Rosa 11315, La Pintana, Santiago, Chile.
Gerardo
G
Valenzuela
Facultad de Ciencias, Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.|Center of Applied Ecology and Sustainability, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, 6513677, Chile.
Sergio A
SA
Estay
D017360:Arabidopsis / Q000033:anatomy & histology*; D008954:Models, Biological; D009929:Organ Size; D010363:Pattern Recognition, Automated / Q000379:methods*; D054046:Plant Stomata / Q000033:anatomy & histology*
finite-size objects; nearest neighbor distance; spatial patterns; stomata patterning; stomata size