Chinese tree plantation operator Sino-Forest (TRE.TSX), under attack by short sellers who accuse it of overstating its timber holdings, recovered 30% in Toronto yesterday after Boston-based investment firm Wellington Management revealed it owned a 11.5% stake in the company, Bloomberg reported. Wellington, which manages US$663 billion in assets, appears to have massively increased its holdings since the beginning of the year: On December 31, 2010, Wellington owned 79,700 Sino-Forest shares, whereas today it holds 28.3 million shares at a value of US$94.5 million. Sino-Forest shares lost 82% of their value after short seller Carson Block’s firm Muddy Waters issued a report accusing Sino-Forest of overstating its tree-plantation holdings. “Maybe they know something the bears don’t,” said Arthur Salzer, Toronto-based chief executive officer of Northland Wealth Management. “If they believe Sino has more licenses than Muddy Waters thinks they do, there might be value there.” Block said that he remains convinced that Sino-Forest is a fraud.