Herbivore grazing can alter leaf photosynthetic rates (McNaughton 1979), the above ground production (Frank and McNaughton 1993) and the C allocation below ground (Frank et al. 2002).
However, at the Aberystwyth site, below ground biomass was much greater in all genotypes, and allocation below ground tended to increase, especially during the second rotation.
With increasing humidity allocation below ground is predicted to increase, as demonstrated in silver birch and aspen in a humidity manipulation experiment [55].
Our data from the Harpenden site agree with the study by Rytter [15], which showed that the below ground biomass of willow increased with plant age, but overall allocation below ground fell.
Annual net primary productivity of root biomass increased from 1 to 3 years, but the actual allocation below ground declined each year from 25 30% to 10 12% of total biomass in 1- and 3-year old plants, respectively.
Contrary to our predictions, total Justicia biomass was unrelated to disturbance by flooding as indicated by the likelihood of streambed movement by bankfull discharge, nor was biomass allocation to below-ground structures positively related to likelihood of substrate movement.
In addition, an increasing temperature decreased the root to shoot ratio, which suggests that biomass allocation between below- and above ground parts of the plants was strongly affected by the temperature.
When competition is mostly for soil resources (e.g. in situations with low soil fertility or high water stress), allocation to below-ground resource capture (measured by high R S, high specific root length, high fine root production) improves plant performance (McGraw and Chapin 1989; Aerts et al. 1991; Tilman and Wedin 1991; Casper and Jackson 1997; Aerts and Chapin 2000).
However, in this paper, we will only discuss the partial usage of subchannel (PUSC) allocation scheme (detailed below) as it is the mandatory allocation scheme for the first zone in each DL subframe.
Such a meagre allocation was below what the Army needed to maintain its strength, and formations had to be disbanded.
