Nagato has good chances if he'll use Gedo Mazo on top of his six paths. Gedo Mazo is much bigger than a Biju and with the power of seven Bijus its shockwaves would be able to cause high damage on Hashirama and his trees. Shinra Tensei wouldn't be the right choice to avoid Hashiramas wood release. His strongest Shinra Tensei would probably be able to repell Hashiramas offensive Mokuton-Jutsu, but a high interval would be the only result for Nagato - Hashirama would create the next forest in an instant. Nagatos bird summoning would be indeed a good way to keep distance to Hashirama, the Kages avoided Madaras Mokuton by the same way. But on the other side, Hashirama can create a very huge amount of wood and trees, perhaps enough to reach even Nagato. The only useful summoning for Nagato besides the bird would be his dividing Dog, because I can't imagine how the Mokuton will defeat them. Any other summoning of Nagato will easily be crushed by the wood release.
Preta-, Asura-, Naraka- and the Human-Path would not be really helpful. Of course Nagato could take out Hashiramas soul by touching him, but I'm pretty sure that Hashirama will be able to keep the distance to Nagato. Preta-Path is able to absorb chakra and chakraattacks, against the Mokuton it would not be a help. Naraka-Path is not worth talking about and Nagatos Asura-Path would be in my view not enough to withstand Hashiramas ability to create giant forests.
Chibaku Tensei is apparently the only way, to defeat Hashirama.
