New Zealand's log export trade to China could take four to six months to recover and it's unlikely prices will revisit recent highs any time soon, rural economists said.

Logs are piling up on Chinese wharves as a wave of cheap timber makes its way by train into China from Eastern Europe, toppling prices along the way.

At the same time, economic growth in China is cooling and the renminbi is weakening.

"A" grade log prices have gone from US$138/140 a tonne early in the year to US$110 a tonne, and could sink as low as US$100 to US$105/tonne.