Aqueous leaf leachate and leaf volatile of

Eucalyptus urophylla

were used to test their effects on seed germination and seedling growth of eight native tree species

including

Schefflera octophylla



Acmena acuminatissima

〖WTBX〗

Cleistocalyx operculatus

Ilex triflora

Schima superba

Cyclobalanopsis myrsinaefolia

Hovenia dulcis

Michelia maclurei

. The results showed that aqueous leaf leachate had no suppression on the seed germination of all receptors. Aqueous leaf leachate had inhibition on the seedling growth of

Schefflera octophylla

Acmena acuminatissima

and

Ilex triflora

while it had a promotion on that of

Cyclobalanopsis myrsinaefolia

and

Hovenia dulcis

at higher concentration. Leaf volatile had inhibitory effect on the seed germination of

Acmena acuminatissima

and

Schima superba

at higher concentration of 350 g leaf weight per desiccator

and

Schima superba

at 250 g leaf weight. However

it had no suppression on them under 150 g leaf weight treatment. On the other hand

leaf volatile had a significant suppressive effect on

the

seedling growth

of

Acmena acuminatissima

Ilex triflora

Schima superba

Hovenia dulcis

and

Michelia maclurei

at all concentrations. Leaf volatile also effectively decreased the seedling growths of

Schefflera octophylla

and

Cleistocalyx operculatus

at 250 g and 350 g leaf weight. It did not inhibit the growth of

Cyclobalanopsis myrsinaefolia

utill at the concentration of 350 g leaf weight. With these results

we can conclude that

Eucalyptus urophylla

has allelopathy and the allelochemical effects of the donor varies with the dose.It seems that allelopathy of leaf volatile is more intense than that of aqueous leaf leachate. Nevertheless

seedling growth is more easily suppressed than seed germination.