Opposite results between Blomberg's K and phylogenetic signal in Phylocom (AOT)
I think I figured. Someone told me that the above results are the same. The absolute value of K = 0.29 indicates the magnitude of the signal is less than expected under a Brownian motion process, but it’s still more than random expectation (according to the P-value,P = 0.001). So both methods suggest that treewise phylogenetic conservatism is significantly greater than random expectations.

Actually the meanings of K statistic and P-value were clearly stated in the original paper (Blomberg et al. 2003). I should have looked at it first... but anyway, I think it is solved now.