Crown-rise and crown-length dynamics: application to loblolly pine

TL;DR: The spatially explicit and spatially inexplicit mixed-effects HCB models using measurements from a total of 19,404 trees of Norway spruce and European beech on the permanent sample plots that are located across the Czech Republic confirmed that the model was precise enough for the prediction of HCB for a range of site quality, tree size, stand density, and stand structure.

TL;DR: A novel hierarchical approach to the detection of 3-D changes in forest areas is proposed that can accurately detect large changes, exhibiting a low rate of false and missed alarms and can detect changes in terms of single-tree growth, which are consistent with the expected growth rates of the considered areas.

TL;DR: Models linking knot ontogeny to the secondary growth of the main stem in black spruce provide support for ‘Milton’s Law,’ since they indicate that allocation priority is given to locations where the potential return is the highest.

TL;DR: In this article, the authors used a mixed-effects model to predict the crown-to-bole diameter ratio (CDBDR), which is a ratio of maximum crown width to diameter at breast height.

Abstract: A tree growth model is formulated based on structural relationships in a carbon balance framework. Three relationships are applied: (1) an allometric relationship between crown surface area and foliage area, (2) the principle of functional balance, and (3) the pipe-model theory. These assumptions lead to a model where the sizes of the functional parts of the tree are derivable from foliage weight, except for the pruning height of the crown. This is determined by defining a "self-pruning coefficient," which controls the allocation of growth between height growth and foliage growth. The tree model is applied to an average-tree based stand growth model where both the self-pruning coefficient and tree mortality are made functions of crown coverage. The model is quantified for Scots pine growing in southern Fenno-Scandia. The overall behavior of the model is realistic. The model responds to stocking density through the rate of self-pruning, lower stocking densities leading to larger crown ratios. It also responds to changes in parameters describing site quality in a realistic way, although the differences in stand density are not as large as expected. The predicted development of the biomass compartments in individual trees agrees well with data on dominant Scots pine trees in Finland. For. Sci. 43(1):7-24.

TL;DR: A new, simple and rapidly-implemented model, with parameters for US tree species, opens up new possibilities for understanding and modeling forest dynamics at local and regional scales, and may provide a new way to interpret remote sensing data of forest canopies, including LIDAR and aerial photography.

TL;DR: Branch autonomy is an important and useful principle, but it is not an absolute rule governing branch growth, and branches are sufficiently interdependent that a positive carbon budget by itself does not ensure branch survival.