adaptation california crops cropsandsoils ecophysiology effectofmineralson effectoftraceelementson energymetabolism evolution extremeenvironments masstransfer metabolism mineralcycle(biogeochemistry) nutrition plantecology plants rainforestecology rareplants sandduneplants savannaecology serpentinecontent serpentineplants soilmineralogy soils sweden traceelementcontent traceelements tropics