Models of 3D crown structure for Scots pine (Pinus sylvestris) and silver birch (Betula pendula) grown in mixed forest

Abstract

The interplay between plant structure and functioning determines vital plant characteristics, such as the efficiency of light capture by the foliage, and thus continuous efforts have attempted to include plant architecture in plant growth models. We constructed two crown structure models enabling the generation of 3D trees using simple tree measurements as input for Scots pine ( Pinus sylvestris L.) and silver birch ( Betula pendula Roth.), boreal species growing in mixed stands. The data for the models were obtained from sample-based digitizing of 3D crown architecture accompanied by characterizations of stem, branch, and foliage volumes and biomass. A set of equations was used to predict local crown characteristics on the basis of local predictors and tree-level input variables such as tree height, crown height, diameter at breast height, and the degree of competition. The 3D tree model was realized within the LIGNUM tree modelling framework. Comparison with data showed that the model adequately predicts the distribution of biomass into different crown components as well as the distribution of foliage within the tree crowns. The applicability of the simulations is at its best when examining Scots pine and silver birch trees growing on medium fertile mixed stands in Finland.

Chamber measured soil respiration: A useful tool for estimating the carbon balance of peatland forest soils?

“…Another challenge to be met is that the CO 2 efflux from leafless parts of branches was not included in either R stem or R shoot . Yet, their respective surface area can be as high as that of the stems (data of Lintunen et al, 2011), thus providing a substantial path for CO 2 efflux from the tree stand. GPP floor has received some attention in boreal forest ecosystems (Badorek et al, 2011;Morén and Lindroth, 2001;Kolari et al, 2006;Kulmala et al, 2011;Tupek et al, 2008), but models for upscaling have not yet been developed.…”

Towards an enhanced understanding of airborne LiDAR measurements of forest vegetation

“…Models were built for birch, raspberry and fireweed. The 3D structure of birch was modeled using an empirical model by Lintunen et al (2011). In the model, a set of regression equations predict local crown characteristics recursively on the basis of local predictors and tree-level input variables such as tree h, crown length, d 13 , and the degree of between-tree competition.…”

Crown responses to neighbor density and species identity in a young mixed deciduous stand

“…that eventually shape crown morphology (Fournier et al 2013). Moreover, this approach provides the basis for a procedure to reconstruct crown geometry from a set of attributes that are relatively easy to measure in the stands, and that can afterwards be used as an input to growth models or light interception models (Lintunen et al 2011). Using the relationships we established, we could simulate vertical leaf distribution within a mixed stand to test hypotheses, such as if potential complementarity in the leaf area display between the two species could explain the higher productivity found in the mixing where the proportion of both Fagus and Acer in the stand is 50 % (Collet et al 2014).…”