Limits...
Predicting maximum tree heights and other traits from allometric scaling and resource limitations.

Kempes CP, West GB, Crowell K, Girvan M - PLoS ONE (2011)

Bottom Line: In addition to predicting maximum tree height in an environment, our framework can be extended to predict how other tree traits, such as stomatal density, depend on these resource constraints.Furthermore, it offers predictions for the relationship between height and whole canopy albedo, which is important for understanding the Earth's radiative budget, a critical component of the climate system.Because our model focuses on dominant features, which are represented by a small set of mechanisms, it can be easily integrated into more complicated ecological or climate models.

View Article: PubMed Central - PubMed

Affiliation: Department of Earth Atmosphere and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America. ckempes@mit.edu

ABSTRACT
Terrestrial vegetation plays a central role in regulating the carbon and water cycles, and adjusting planetary albedo. As such, a clear understanding and accurate characterization of vegetation dynamics is critical to understanding and modeling the broader climate system. Maximum tree height is an important feature of forest vegetation because it is directly related to the overall scale of many ecological and environmental quantities and is an important indicator for understanding several properties of plant communities, including total standing biomass and resource use. We present a model that predicts local maximal tree height across the entire continental United States, in good agreement with data. The model combines scaling laws, which encode the average, base-line behavior of many tree characteristics, with energy budgets constrained by local resource limitations, such as precipitation, temperature and solar radiation. In addition to predicting maximum tree height in an environment, our framework can be extended to predict how other tree traits, such as stomatal density, depend on these resource constraints. Furthermore, it offers predictions for the relationship between height and whole canopy albedo, which is important for understanding the Earth's radiative budget, a critical component of the climate system. Because our model focuses on dominant features, which are represented by a small set of mechanisms, it can be easily integrated into more complicated ecological or climate models.

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Related in: MedlinePlus

The relationship between tree height and the total albedo for the canopy of a single tree.The red points are data [67], and the blue curve is our generalized model for a tree using a soil reflection coefficient of  and a deep canopy reflection coefficient of  [51] (see Supplement S1). We have not included error bars here because ref. [67] does not provide them for every point.
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pone-0020551-g004: The relationship between tree height and the total albedo for the canopy of a single tree.The red points are data [67], and the blue curve is our generalized model for a tree using a soil reflection coefficient of and a deep canopy reflection coefficient of [51] (see Supplement S1). We have not included error bars here because ref. [67] does not provide them for every point.

Mentions: For the average tree whose features are encapsulated in the scaling relationships, these derivations have predictive power beyond determining maximum height. For example, our model predicts the specific form of the decrease in canopy albedo with increasing tree height in excellent agreement with data, as illustrated in Fig. 4 (please see Supplement S1 for a derivation). Albedo plays a critical role in many questions related to the earth system and our model framework provides a quantitative means for linking albedo to tree heights and thereby to local resources.


Predicting maximum tree heights and other traits from allometric scaling and resource limitations.

Kempes CP, West GB, Crowell K, Girvan M - PLoS ONE (2011)

The relationship between tree height and the total albedo for the canopy of a single tree.The red points are data [67], and the blue curve is our generalized model for a tree using a soil reflection coefficient of  and a deep canopy reflection coefficient of  [51] (see Supplement S1). We have not included error bars here because ref. [67] does not provide them for every point.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3113805&req=5

pone-0020551-g004: The relationship between tree height and the total albedo for the canopy of a single tree.The red points are data [67], and the blue curve is our generalized model for a tree using a soil reflection coefficient of and a deep canopy reflection coefficient of [51] (see Supplement S1). We have not included error bars here because ref. [67] does not provide them for every point.
Mentions: For the average tree whose features are encapsulated in the scaling relationships, these derivations have predictive power beyond determining maximum height. For example, our model predicts the specific form of the decrease in canopy albedo with increasing tree height in excellent agreement with data, as illustrated in Fig. 4 (please see Supplement S1 for a derivation). Albedo plays a critical role in many questions related to the earth system and our model framework provides a quantitative means for linking albedo to tree heights and thereby to local resources.

Bottom Line: In addition to predicting maximum tree height in an environment, our framework can be extended to predict how other tree traits, such as stomatal density, depend on these resource constraints.Furthermore, it offers predictions for the relationship between height and whole canopy albedo, which is important for understanding the Earth's radiative budget, a critical component of the climate system.Because our model focuses on dominant features, which are represented by a small set of mechanisms, it can be easily integrated into more complicated ecological or climate models.

View Article: PubMed Central - PubMed

Affiliation: Department of Earth Atmosphere and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America. ckempes@mit.edu

ABSTRACT
Terrestrial vegetation plays a central role in regulating the carbon and water cycles, and adjusting planetary albedo. As such, a clear understanding and accurate characterization of vegetation dynamics is critical to understanding and modeling the broader climate system. Maximum tree height is an important feature of forest vegetation because it is directly related to the overall scale of many ecological and environmental quantities and is an important indicator for understanding several properties of plant communities, including total standing biomass and resource use. We present a model that predicts local maximal tree height across the entire continental United States, in good agreement with data. The model combines scaling laws, which encode the average, base-line behavior of many tree characteristics, with energy budgets constrained by local resource limitations, such as precipitation, temperature and solar radiation. In addition to predicting maximum tree height in an environment, our framework can be extended to predict how other tree traits, such as stomatal density, depend on these resource constraints. Furthermore, it offers predictions for the relationship between height and whole canopy albedo, which is important for understanding the Earth's radiative budget, a critical component of the climate system. Because our model focuses on dominant features, which are represented by a small set of mechanisms, it can be easily integrated into more complicated ecological or climate models.

Show MeSH
Related in: MedlinePlus