Worldwide, a total of 164 people were killed in related violence -- an average of more than three per week -- according to the "Enemies of the State?" report from NGO Global Witness. Mining conflicts were responsible for the largest share of the deaths.
But in the Philippines, disputes linked to agribusiness led to half of the killings, according to the research. Such conflicts have increased in the Southeast Asian nation due to President Rodrigo Duterte's plans to hand 1.6 million hectares of land over to industrial plantations.
At the same time, Duterte's "war on drugs," which has led to thousands of extrajudicial killings, is creating a "culture of fear," according to the NGO.
Despite the increased focus on environmental issues the world over, the proliferation of strongmen leaders is bringing greater danger for those trying to defend their rights, Global Witness says. And the situation is likely to deteriorate in 2019, it predicts.
The report reveals that Guatemala saw the sharpest increase in fatalities, which increased fivefold from 2017 to 2018. Central America's most populous nation saw 16 people killed while protecting land or the environment, making it one of the world's deadliest countries per capita.
Latin America was the worst-affected continent, with over 50% of the worldwide killings taking place there in 2018. The region has held this unwelcome title since Global Witness started its reports in 2012.
Colombia saw 24 environmental defenders killed, followed by India on 23 and Brazil on 20.