Water transport in plants obeys Murray's law

  title={Water transport in plants obeys Murray's law},
  author={Katherine A. McCulloh and John S. Sperry and Frederick R. Adler},
The optimal water transport system in plants should maximize hydraulic conductance (which is proportional to photosynthesis) for a given investment in transport tissue. To investigate how this optimum may be achieved, we have performed computer simulations of the hydraulic conductance of a branched transport system. Here we show that the optimum network is not achieved by the commonly assumed pipe model of plant form, or its antecedent, da Vinci's rule. In these representations, the number and… 
Murray's law, the 'Yarrum' optimum, and the hydraulic architecture of compound leaves.
Competence with both optima within the xylem of compound leaves, where conduits should have a minimal mechanical role, is evaluated, indicating that taper is optimized for a constrained conduit number.
The Widened Pipe Model of plant hydraulic evolution
The Widened Pipe Model (WPM) of plant hydraulic evolution predicts that xylem conduits should be narrowest at the stem tips, widening quickly before plateauing toward the stem base, and implies that factors that cause resistance in plant conductive systems, such as conduit pit membrane resistance, should scale in exact harmony with tip-to-base conduit widening.
Patterns in hydraulic architecture and their implications for transport efficiency.
Murray's law was used to identify the conduit taper that maximizes k(L)for a given vascular investment, and observed architectural patterns are consistent with the maximization of transport efficiency operating within mechanical constraints.
Comparative Criteria for Models of the Vascular Transport Systems of Tall Trees
During the past decade, several detailed models of plant vascular transport systems (i.e. xylem and phloem) have been presented in the literature, and many of them are currently capable of accurately
Ontogenetically stable hydraulic design in woody plants
Vessel radii are determined by distance from the top of the tree, as well as by stem size, independently of tree height or age, suggesting the existence of an ontogenetically stable hydraulic design that scales in the same manner as a tree grows in height and diameter.
Murray's law and the hydraulic vs mechanical functioning of wood
It is hypothesized that Murray’s law will apply to xylem conduits as long as they only transport water and do not also help support the plant, and that the less volume of wood occupied by conduits, the more the conduits should conform to Murray's law.
Hydraulic trade-offs and space filling enable better predictions of vascular structure and function in plants
A theory for plant network scaling that is based on optimal space filling by the vascular system along with trade-offs between hydraulic safety and efficiency is developed, suggesting that the evolutionary drivers that are proposed have been fundamental in determining how physiological processes scale within and across plant species.
Long-distance liquid transport in plants
A brief review of the thermodynamic and fluid dynamic problems related to long-distance liquid flow and signalling in plants is presented. Geometrical parameters of the plant leaf venation are
Maintenance of carbohydrate transport in tall trees
This work examines how trees can maintain efficient carbohydrate transport as they grow taller by analysing sieve tube anatomy, including sieve plate geometry, using recently developed preparation and imaging techniques, and by measuring the turgor pressures in the leaves of a tall tree in situ.


Stomatal conductance and photosynthesis vary linearly with plant hydraulic conductance in ponderosa pine
Recent work has shown that stomatal conductance (gs) and assimilation (A) are responsive to changes in the hydraulic conductance of the soil to leaf pathway (KL), but no study has quantitatively
A general model for the structure and allometry of plant vascular systems
Vascular plants vary in size by about twelve orders of magnitude, and a single individual sequoia spans nearly this entire range as it grows from a seedling to a mature tree. Size influences nearly
The Transpiration Stream in the Leaf Apoplast: Water and Solutes
Flow of the transpiration stream in the lumen apoplast of the xylem appears hydrodynamically orthodox in being approximately described by the Hagen-Poiseuille Law, and by Murray's Law for branching
The Effect of Reduced Hydraulic Conductance on Stomatal Conductance and Xylem Cavitation
This work studied the ability of the stomata to prevent cavitation-inducing pressures when whole-plant hydraulic conductance per leaf area was reduced by making overlapping transverse cuts in the main stem.
Principles of design of fluid transport systems in zoology.
By exploiting the signal inherent in local shear stress on the vessel walls, animals have repeatedly evolved a complex branching hierarchy of vessels approximating a globally optimal system that minimizes the costs of the construction and maintenance of the fluid transport system.
Environmental and physiological regulation of transpiration in tropical forest gap species: the influence of boundary layer and hydraulic properties
Environmental and physiological regulation of transpiration were examined in several gap-colonizing shrub and tree species during two consecutive dry seasons in a moist, lowland tropical forest on Barro Colorado Island, Panama to suggest that contrasting stomatal responses to similar leaf-bulk air VPD may be governed as much by the external boundary layer as by intrinsic physiological differences among species.
The Physiological Principle of Minimum Work: I. The Vascular System and the Cost of Blood Volume.
  • C. D. Murray
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1926
The purpose of these studies is to discuss the possible application of a second principle, the principle of minimum work, to problems concerning the operation of physiological systems.
A General Model for the Origin of Allometric Scaling Laws in Biology
The model provides a complete analysis of scaling relations for mammalian circulatory systems that are in agreement with data and predicts structural and functional properties of vertebrate cardiovascular and respiratory systems, plant vascular systems, insect tracheal tubes, and other distribution networks.
Influence of leaf water status on stomatal response to humidity, hydraulic conductance, and soil drought in Betula occidentalis
Whole-canopy measurements of water flux were used to calculate stomatal conductance (gs) and transpiration (E) for seedlings of western water birch (Betula occidentalis Hook.) under various