DOI: 10.5061/dryad.0k6djhb0m
title: Terrestrial laser scanning (TLS) data on tree crown morphology and neighbourhood competition from both Cuellar and Alto Tajo, Spain

description: 1. Tree crown morphology is a key driver of forest dynamics, determining
 not only the competitiveness of an individual but also the competitive
 effect exerted on neighbouring trees. Multiple ecological theories,
 including Metabolic Scaling Theory (MST), predict crown morphology from
 first principles, but typically lack consideration of competition. The
 accurate quantification of crown morphology to test theoretical
 predictions, and the canopy interactions that could alter them, has
 historically been limited by the simplicity and associated error of
 traditional crown measurements. 2. In this study, we calculate high
 resolution two and three-dimensional crown metrics from Terrestrial Laser
 Scanning data for 1441 Pinus. sylvestris, P. nigra, Quercus. faginea and
 Q. ilex trees from a water-limited forest community in central Spain and
 test height-crown metric scaling relationships. We demonstrate new TLS
 methods to define symmetric and asymmetric neighbourhood metrics based on
 tree height, crown size and neighbour projected crown area, and test the
 importance of neighbourhood genus diversity on crown morphology by
 separating competition from congeneric and heterogeneric neighbours. 3.
 Competition negatively impacted all crown metrics except crown depth where
 only P. nigra showed sensitivity. Asymmetric competition was the strongest
 driver of pine crown morphology, but oaks were more sensitive to symmetric
 competition, in line with shade tolerance expectations. Congeneric
 competition reduced Q. faginea crown size and changed its shape, but we
 found no significant effects of heterogeneric neighbours. Most species and
 crown dimensions had height-crown scaling exponents below those predicted
 by MST, which may be due to water-limitation effects. Pines and oaks
 showed large differences in crown depth to height scaling, with the former
 shallower and the latter deeper, in contrast to theoretical predictions.
 4. Synthesis. Our study is the first to demonstrate the ability of TLS to
 characterise crown morphology from leaf-wood separated clouds and
 competitive neighbour effects in a water-limited forest community, and to
 use TLS metrics to test ecological crown scaling theory. Most crown
 metrics scaled below theoretical predictions. Pines were more sensitive to
 competition by larger neighbours and oaks to crowding from all neighbours,
 with competition from neighbours of the same genus having a consistently
 negative effect.
description: See published article in Journal of Ecology for all
 methodological information. 
description: The file focaltree_dataset.csv includes: Each
 tree id with the prefix "alt" and "cue" corresponding
 to alto tajo and cuellar field sites.  Fields 1:2
 contain tree height and dbh for each focal tree. DBH values of 0 are
 NA's.  Fields 4:9 contain crown morphological
 metrics.  Fields 10:11 contain species and
 genus. Fields 12:17 contain neighbourhood competition
 metrics.  Field 18 contains binary column on whether
 species is [1] or isn't [0] a miltistemmed tree. 
 Field 19 contains plot ID.  Field 20 contains
 site ID.