The occurrence of gummosis on invasive Acacia decurrens after Mount
Merapi eruption in Yogyakarta, Indonesia
Abstract
1. Gummosis on Acacia decurrens, an invasive tree species, that got
established in Merapi Volcano National Park (MVNP) after the eruption of
Mount Merapi in 2010 was studied to i) identify the causal organism of
the disease, ii) analyze disease symptoms, iii) understand the
spatio-temporal distribution of gummosis in the tree population and iv)
examine how the disease affects the anatomy of tree wood. 2.
Pathological, morphological and molecular studies were used in this
studies. 3. Ceratocystis fimbriata was proved to be the causal organism
of the disease. The disease spread was probably aided by the ambrosia
beetle (Euwallacea sp.) which bores holes on the stem. 4. The disease is
noted to spread from the base of the trees, where the ambrosia beetle
bores holes first, to the upper part. 5. The number of parenchyma cells
in the infected stem was significantly more than in the healthy stem
which apparently facilitated water and nutrition transport within the
tree helping it to grow normally despite serious gummosis. 6. The
management of invasion by A. decurrens in the MVNP area poses a serious
challenge due its success as an invader in the volcano impacted area and
the threat of the gummosis pathogen spreading to other species both of
which will affect the regeneration and establishment of native species
and recuperation of the ecosystem.