Designing forest vegetation management strategies based on the mechanisms and dynamics of crop tree competition by neighbouring vegetation

Plant interactions can be defined as the ways plants act uponthe growth, fitness, survival and reproduction of other plants,largely by modifying their environment. These interactions canbe positive (facilitation) or negative (competition or exploitation).During plantation establishment or natural forest regenerationafter a disturbance, high light levels and, sometimes, increasedavailability of water and nutrients favour the development ofopportunistic, fast-growing herbaceous and woody species whichcapture resources at the expense of crop trees. As a consequence,the growth and survival of crop trees can be dramatically reduced.Although the effects of this competition are well documented,the physical and physiological mechanisms of competition arenot. Moreover, the competition process is never constant intime or space. We present a conceptual competition model basedon plant growth forms common in global forests, i.e. graminoids,forbs, small shrubs, large shrubs and mid-storey trees, andmain-storey trees. Their competitive attributes and successionaldynamics are examined. An overview is presented on the way forestvegetation management (FVM) treatments influence these componentsand outcomes regarding crop tree performance and diversity conservation.Finally, a synthesis of literature yields FVM guidelines forefficiently optimizing crop tree performance and safeguardingdiversity. Future research needs to further sustainable FVMare presented.