Scientists gathered 146 research papers to see how people put price tags on nature's help in farming and tree-growing systems. They followed a review method called PRISMA. They mixed the results together using math models and looked at maps to see if location mattered. The goal was to figure out if the way we measure nature's value changes the final number. They also checked for bias in the published results.
Two methods showed up most often. One uses market prices. The other asks people what they would pay. Market prices appeared in about 26 percent of the papers. The ask-people method appeared in about 21 percent. These two approaches link different kinds of nature benefits, such as food, clean water, and places to relax. A third method, life cycle reviews, also helps connect all the gr