REVIEW OF ROOT DYNAMICS IN FOREST ECOSYSTEMS GROUPED BY CLIMATE, CLIMATIC FOREST TYPE AND SPECIES

Patterns of both above- and belowground biomass and production were ev aluated using published information from 200 individual data-sets. Dat a sets were comprised of the following types of information: organic m atter storage in living and dead biomass (e.g, surface organic horizon s and soil organic matter accumulations), above and belowground net pr imary production (NPP) and biomass, litter transfers, climatic data (i .e, precipitation and temperature), and nutrient storage (N, P, Ca, K) in above- and belowground biomass, soil organic matter and litter tra nsfers. Forests were grouped by climate, foliage life-span, species an d soil order. Several climatic and nutrient variables were regressed a gainst fine root biomass or net primary production to determine what v ariables were most useful in predicting their dynamics. There were no significant or consistent patterns for above- and belowground biomass accumulation or NPP change across the different climatic forest types and by soil order. Similarly, there were no consistent patterns of soi l organic matter (SOM) accumulation by climatic forest type but SOM va ried significantly by soil order - the chemistry of the soil was more important in determining the amount of organic matter accumulation tha n climate. Soil orders which were high in aluminum, iron, and clay (e. g. Ultisols, Oxisols) had high total living and dead organic matter ac cumulations - especially in the cold temperate zone and in the tropics . Climatic variables and nutrient storage pools (i.e. in the forest fl oor) successfully predicted fine root NPP but not fine root biomass wh ich was better predicted by nutrients in litterfall. The importance of grouping information by species based on their adaptive strategies fo r water and nutrient-use is suggested by the data. Some species groups did not appear to be sensitive to large changes in either climatic or nutrient variables while for others these variables explained a large proportion of the variation in fine root biomass and/or NPP.