Uncertainty is increasing globally, with populism and protectionism now credible risks to real assets investment, according to Andrew Rose, chief executive of the Global Infrastructure Investor Association.

“Investors want a stable, regulatory environment,” Rose told delegates at IPE Real Estate’s Real Assets & Infrastructure conference in London.

There are, he said, “potentially strong head-winds” for global investors.

The UK’s vote to leave the European Union has increased uncertainty, Rose said, echoing the views of BlackRock’s head of real assets, Jim Barry.

Barry this week told IPE Real Assets 2016 delegates that Brexit is “not something to be passive about”.

A British exit from the European Union is expected to have no effect on most investors’ infrastructure strategies, according to the latest IPE Institutional Infrastructure Survey, launched at the conference in London.

Nearly 80% said Brexit would have no effect – although 18.5% said they would reduce their existing and future investments in the UK.

Delegates heard how both agriculture and timberland provide an opportunity for long-term investors.

“Forestry has been one of those undiscovered areas among investors as they look for returns,” Richard Davidson, investment committee chair of Gresham House’s forestry fund.

“Biological growth is unrelated to economics interest rates and markets,” he said.

UK timber prices, he said, are historically low, with long-term returns of between 7.5% and 10%.

“Our view is that prices will rise 1% per year over next 10 years,” said Davidson, who joined the firm this year from Morgan Stanley.

The forestry sector, said fellow panellist, Henrik Lundqvist, chief investment officer of IWC Investment Partners, offers investors stable returns.

Agriculture, delegates heard earlier in the day, remains a “family-run business”, according to Martin Davies, chief executive of TIAA’s Westchester Group.

“Over time, generational change means there will be lots of room for institutional capital,” he said. “It’s not a new concept, but the sector has an average age of 55.”

Davies said consolidation in the agriculture sector would lead to larger, professional farms, which will require “patient capital” and “good quality management”.

Duncan Symonds, European direct of asset management at IFM Investors, told delegates that investors in infrastructure need to “avoid recruiting generalists” if they are to treat real assets sub-sectors correctly.

In the listed infrastructure sector, greater consensus is needed on benchmarking, according Larry Antonatos, managing director of direct global equities at Brookfield Investment Management.

Antonatos said an “industry standard benchmark” is needed.

“Indices for private infrastructure can be integrated with listed indices,” he said.