FROM TROPICS TO TUNDRA - GLOBAL CONVERGENCE IN PLANT FUNCTIONING

Despite striking differences in climate, soils, and evolutionary histo ry among diverse biomes ranging from tropical and temperate forests to alpine tundra and desert, me found similar interspecific relationship s among leaf structure and function and plant growth in all biomes. Ou r results thus demonstrate convergent evolution and global generality in plant functioning, despite the enormous diversity of plant species and biomes, For 280 plant species from two global data sets, me found that potential carbon gain (photosynthesis) and carbon loss (respirati on) increase in similar proportion with decreasing leaf life-span, inc reasing leaf nitrogen concentration, and increasing leaf surface area- to-mass ratio, Productivity of individual plants and of leaves in vege tation canopies also changes in constant proportion to leaf life-span and surface area-to-mass ratio, These global plant functional relation ships have significant implications for global scale modeling of veget ation-atmosphere CO2 exchange.