Study on Crop Growth Rate and Relative Growth Rate of Growth Analytical Parameters in Wheat, Barley and Oat

Abstract

The study reported here describes for the first time the similaritybetween pre- and post-fire spatial patterns of the trees in a Mediterraneanpine forest demonstrating that the pre-fire ancestor microsite isoccupied also by the next generation. Although Aleppo pine Pinushalepensis Mill. is an obligatory post-fire seeder, it is adaptedto regenerate in its pre-fire growing microsite, thus keeping suitablegrowing sites From generation to generation. We studied the effectof the dead burned adult pines on the density and size of their recruitedsaplings 2, 5, 11 and 20 yr after fire. A comparison of pine saplingdensity and size was made between the 'near' zone (under the formereffect of the burned canopy) and the 'far' zone (beyond the formereffect of the burned canopy). In the site 2 yr after fire, seedlingdensity was 56% higher in the 'far' zone than in the 'near' zone,but seedling size was similar. However in the site 20 yr after fire,densities were similar in both zones, but the size was bigger by89% in the 'near' zone. Thus, population recruitment after fire seemsto peak near the burned pine trees rather than at a distance fromthem, in contrast to Janzen's original 'distance hypothesis' modelsuggested for undisturbed rainforest. Here we present a new hypotheticalmodel for the spatial pattern of post-fire regeneration of obligateseeder tree species forming open forests. It is proposed that insuch trees the microsites which were kept by the burned adult trees,which are killed by the fire, are also the Favorable regenerationmicrosite for the post-fire generation.