Yu is a native of Nanjing, and he spoke of fond memories about the trees.
"They are my last friends in Nanjing. Everything else has changed in the city. The trees remain constant; that keeps us from getting lost," he told China Daily.
"The Chinese proverb says, 'Forefathers plant trees, and later generations enjoy the shade.' It will be too sad to see 'later generations chop them off, or remove them."
He called on deeper involvement by non-governmental organizations.
"Third-party expertise should be invited to assess the projects; that will give credibility to the projects assessment." Yu said. "Ordinary residents' involvement should be encouraged but is far from enough. Experts . . . should all play a part in the decision-making."
Those experts were named in the mayor's announcement of the advisory panel on the landscape and urban projects.