Delagrange2004

Report for study: Delagrange2004

Contact Information

Data contributor: Sylvain Delagrange

Email: sylvain.delagrange@uqo.ca

Address:

• Departement des sciences naturelles, Universite du Quebec en Outaouais, Institut des Sciences de la Forêt Tempérée (ISFORT), 58 rue principal, Ripon (Quebec) J0V 1V0, Canada

Data source

Citation: Delagrange S, Messier C, Lechowicz MJ and Dizengremel P (2004). 'Physiological, morphological and allocational plasticity in understory deciduous trees: importance of plant size and light availability.' Tree Physiology, 24(7), pp. 775-784.

DOI: 10.1093/treephys/24.7.775

Abstract: In a 4-year study, we investigated changes in leaf physiology, crown morphology and whole-tree biomass allocation in seedlings and saplings of shade-tolerant sugar maple (Acer saccharum Marsh.) and intermediate shade-tolerant yellow birch (Betula alleghaniensis Britt.) growing in natural understory light (0.5 to 35% of full sunlight) or in understory light reduced by 50% with shade nets to simulate the effect of gap closure. Leaf physiological parameters were mainly influenced by the light gradient, whereas crown morphological and whole-tree allocational parameters were mainly influenced by tree size. No single physiological, morphological or allocational trait was identified that could explain the difference in shade tolerance between the species. Yellow birch had higher growth rates, biomass allocation to branches and leaf physiological plasticity and lower crown morphological plasticity in unmodified understory light than sugar maple. Sugar maple did not display significant physiological plasticity, but showed variation with tree size in both crown morphology and whole-tree biomass allocation. When sugar maple was small, a greater proportion of whole-tree biomass was allocated to roots. However, physiological differences between the species decreased with decreasing light and most morphological and allocational differences tended to disappear with increasing tree size, suggesting that many species differences in shade-tolerance are expressed mainly during the seedling stage. Understory trees of both species survived for 4 years under shade nets, possibly because of higher plasticity when small and the use of stored reserves when taller.

Overview of data provided

The dataset includes records for 92 individuals from 2 species belonging to 2 family(ies), presenting 1 functional type(s), growing in 2 condition(s) within 1 major type(s) of habitat, with data included for the following variables:

Variable	Label	Units	N	Min	Median	Max
latitude	Latitude	deg	92	47	47	47
longitude	Longitude	deg	92	-72	-72	-72
age	Age	yr	91	4	9	23
a.lf	Leaf area	m2	91	0.0028	0.17	2.7
a.stba	Stem area at base	m2	92	0.0000062	0.000091	0.002
a.cp	Crown area	m2	91	0.0031	0.38	5.6
h.t	Height	m	91	0.14	1.1	5.8
h.c	Height to crown base	m	89	0.02	0.54	3.2
d.ba	Basal diameter	m	92	0.0028	0.011	0.05
d.cr	Crown width	m	91	0.062	0.7	2.7
c.d	Crown depth	m	88	0.12	0.58	2.6
m.lf	Leaf mass	kg	92	0.00006	0.0046	0.16
m.st	Total stem mass	kg	92	0.00018	0.017	0.87
m.so	Aboveground mass	kg	92	0.00027	0.023	1
m.br	Branch mass	kg	92	0	0.004	0.41
m.rf	Fine root mass	kg	92	0.00011	0.0039	0.052
m.rc	Coarse root mass	kg	92	0.00039	0.0093	0.45
m.rt	Total root mass	kg	92	0.00056	0.014	0.5
m.to	Total mass	kg	92	0.0012	0.034	1.5
ma.ilf	Leaf mass per area	kg m-2	91	0.015	0.031	0.048
r.st	Wood density	kg m-3	91	790	980	1300
n.lf	Leaf [nitrogen]	kg kg-1	90	0.012	0.026	0.04

And locally within the country:

The sites sampled are:

Location	Longitude	Latitude	Vegetation
Duchesnay, Quebec, Canada	-71.67	46.91	Temperate forest

The growing conditions of sampled plants was:

Location	Grouping	growingCondition
Duchesnay, Quebec, Canada	Group = Shaded individuals; Last perturbation = 5	field experimental, field wild
Duchesnay, Quebec, Canada	Group = Shaded individuals; Last perturbation = 10	field experimental, field wild
Duchesnay, Quebec, Canada	Group = Natural conditions; Last perturbation = 5	field experimental, field wild
Duchesnay, Quebec, Canada	Group = Natural conditions; Last perturbation = 10	field experimental, field wild

Species sampled

Species	Family	Pft
Acer saccharum	Aceraceae	deciduous angiosperm
Betula alleghaniensis	Betulaceae	deciduous angiosperm

Methods used

Sampling strategy: After 4 years of treatment (opening and/or shading nets) 46 sugar maple and 44 yellow birch naturally regenerated were sampled in gaps and in the understory. 1 individual of each species was harvested in each gap excepted if the species was missing.

Leaf area: leaf area was measured on a subsample of leaves to generate LMA. Total leaf mass and LMA was then used to calculate total leaf area

Stem cross sectional area: Stem diameter at collar was measured using a caliper.

Height: Height was measured using a measuring tape.

Crown area: Crown width was calculated as the mean of 2 perpendicular diameters.

Biomass: Tree compartments (roots (fine: < 2 mm, coarse: > 2 mm), stem, branches and leaves) were dried separately at 65degC for 48 h and weighed.

Traits: LMA was measured on cored disks taken from a well exposed leaf used for gas exchange measurments. Leaf nitrogen concentration was measured using an elemental NCS 2500 analyzer (ThermoQuest, Milan Italy). Crown height was measured as the stem lenght supporting alive branches or leaves. Wood density was calculated as the force to displace a volume of water equivalent to stem section volume.

Growth environment: Individuals are naturally regenerated individuals in gaps or in the understory. Shading nets were placed to suppress half of them during 4 years.

Plots of data

This is how the study Delagrange2004 fits in the entire dataset (grey). each colour represents a species. A legend of species names with colours is included at the end for reports with 1 < n < 20 species.