Higher temperatures could initially be favourable for plant growth. Eventually, increased growth would peak then decline.[34] According to IPCC (2007:11), a global average temperature increase exceeding 1.5–2.5 °C (relative to the period 1980–99), would likely have a predominantly negative impact on ecosystem goods and services, e.g., water and food supply.[35] Research done by the Swiss Canopy Crane Project suggests that slow-growing trees only are stimulated in growth for a short period under higher CO2 levels, while faster growing plants like liana benefit in the long term. In general, but especially in rainforests, this means that liana become the prevalent species; and because they decompose much faster than trees their carbon content is more quickly returned to the atmosphere.