Motivated by a case study of vegetation patterns, we introduce a mixture model with concomitant variables to examine the association between the orientation of vegetation stripes and wind direction. The proposal relies on a novel copula-based bivariate distribution for mixed axial and circular observations and provides a parsimonious and computationally tractable approach to examine the dependence of two environmental variables observed in a complex manifold. The findings suggest that dominant winds shape the orientation of vegetation stripes through a mechanism of neighbouring plants providing wind shelter to downwind individuals.

翻译：受植被模式案例研究的启发，我们引入了一种带有伴随变量的混合模型，以检验植被条纹取向与风向之间的关联。该模型基于一种新颖的Copula二元分布，适用于混合的轴向与环形观测数据，为研究在复杂流形上观测到的两个环境变量之间的依赖性提供了一种简约且计算上易处理的方法。研究结果表明，主导风通过邻近植物为下风处个体提供风障的机制，塑造了植被条纹的取向。