Initial results from a study on tree species commonly used for restoration of degraded tropical forests, suggests that the genetic variation in plant performance under water limitation could be utilized to enhance tropical forest restoration in the future.
Although the need for reforestation of degraded tropical forests has been well established, now formalized in multi-national, multi-billion dollar agreements such as the Bonn Challenge to reforest 350 million hectares of the world’s degraded land into restoration by 2030; the technology needed to maximize efficiency lags well behind these large-scale ambitions. Genetic variation in tolerance to the harsh conditions often present at restoration sites, e.g. high solar radiation and decreased water availability has not been evaluated for tropical trees. A controlled experiment was set up in the nursery to test for genetic variation in the response to water availability in five tropical tree species commonly used in restoration of degraded forests in Sabah, Malaysia.
The initial result suggests that there is genetic variation in plant performance that could be utilized to enhance tropical forest restoration in the future. A large among-family variation in growth was demonstrated, i.e. in some cases the growth of fast growing families was double that of slow growing families. It also showed that the response to water availability varies a lot among different families. Whereas some families lost more than half of their growth potential with reduced water availability others maintained their growth potential even under water limitation.
Next step of the project is to evaluate how the genetic variation is seen in the nursery influence plant performance in restoration settings on degraded land and explore genetic variation in interactions with insect herbivores. Part of this work include a new MSc student, Ignatius Nair at University Malaysia Sabah, who has started a two year project (funded through SLU Global) to evaluate genetic variation in insect resistance.
MSc student, Ignatius Nair is documenting leaf damage on seedlings planted in the field.