Puerto Rico, like many regions around the world, is feeling the growing impacts of rising temperatures. This is not an isolated phenomenon.
Human-induced greenhouse gas emissions have increased global temperatures, leading to more frequent and intense heat waves and other extreme weather events. In fact, the last eight years have been the warmest ever recorded. In addition, El Niño events are associated with higher temperatures and reduced rainfall, compounding additional heat stress and increasing the vulnerability of regions such as Puerto Rico to drought and water scarcity.
The conditions created by climate change remind us that the way we shape our territories has lasting consequences. For too long, urban development has pushed nature to the margins, replacing natural ecosystems with impervious surfaces and gray infrastructure. In doing so, we have displaced the essential climate-regulating services these ecosystems provide—cooling our cities, managing stormwater, supporting biodiversity, and improving quality of life.
In urban environments, the impacts of rising global temperatures are amplified by the Urban Heat Island (UHI) effect, a phenomenon in which cities experience significantly higher temperatures than their surrounding suburban or rural areas. Additional heat released from buildings, vehicles, and other human activities further intensifies urban warming, making cities particularly vulnerable to extreme heat. Unlike rural landscapes, heat in cities carries an important social dimension because it directly affects where and how people live, move, work, and interact.
Excessive heat poses serious health risks, particularly for older adults, outdoor workers, pregnant women, people with pre-existing conditions, and socioeconomically disadvantaged communities. Although extreme heat affects communities worldwide, climate adaptation is inherently place-based. That is why our first step was to listen. To better understand how residents experience rising temperatures, we conducted a heat perception survey in Barrio Caguas Pueblo. The survey revealed a clear consensus: temperatures have increased significantly, heat is already affecting people’s health and altering daily routines, and household energy costs are rising. Respondents also overwhelmingly agreed that urban reforestation, together with green infrastructure and the creation of shaded public spaces, represents the most effective strategy for mitigating the Urban Heat Island effect.
Over the past year, we have been putting this collective vision into practice along with our greatest ally. One that transforms carbon dioxide into oxygen, one that improves soil structure and enhances water management, one that can reduce urban surface temperatures by 2–12°C, one that provides habitat for wildlife and carries our cultural memories. The tree, the greatest “machine” in helping us meet this challenge.
Yet planting a tree in a city is fundamentally different from planting one in a natural landscape. Urban trees must survive in environments shaped by anthropogenic conditions, including higher temperatures, vehicle emissions, heavy pedestrian traffic, compacted soils, limited rooting space, poor soil quality, waste, domestic animals, and constant conflicts with infrastructure. Too often, they are treated as obstacles rather than assets, used as trash bins, ashtrays, or pet toilets, rather than being recognized as essential urban infrastructure.
When properly planned, planted, and cared for, however, they have the power to make cities healthier, cooler, and more livable by reducing urban temperatures, improving housing quality and walkability, strengthening biodiversity and water management, mitigating climate risks, and providing cultural and recreational benefits. Successful urban forestry therefore requires far more than planting trees—it demands a holistic understanding of the relationship between trees, people, and the built environment, together with long-term community stewardship.
That is why, over the past year, we have focused on strengthening the community infrastructure needed to make participatory urban reforestation possible and sustainable. Through art workshops, scientific walks, games, and activities that reconnect people with the cultural, alimentary, and traditional values of trees, we have engaged residents from diverse backgrounds as active stewards of their urban reforestation initiatives. We have also built the physical infrastructure needed to support this effort, including community nurseries, rainwater harvesting systems, and community composting initiatives.
Behind Caguas’s urban reforestation effort lies a year of quiet community building, with La Maraña using art workshops, scientific walks, and games to reconnect residents with the cultural value of trees, while establishing community nurseries (photo above), rainwater harvesting systems, and composting initiatives to keep the work growing long after each planting day. Photo courtesy of La Maraña.
In parallel, we have been intentionally investing in building local capacity by training residents in urban tree management, equipping them with the knowledge, tools, resources, and skills to lead and support stewardship efforts long after the project is complete. By cultivating a network of informed community stewards, we are strengthening the long-term governance of urban trees as shared commons.
None of this, however, can be achieved by trees alone. Building resilient urban forests requires the collaboration of diverse stakeholders. Over the past year, we have worked across multiple sectors in Caguas with one shared goal: reducing urban temperatures through participatory urban reforestation. Every interest has a place in the Servicio Forestal Comunitario, a project of La Maraña, a Puerto Rico–based nonprofit organization that advances sustainable development through participatory design. Because everyone has something to contribute, everyone has a role to play in growing and caring for our urban trees.
Our goal is to plant 400 trees in Caguas Pueblo. Every tree we plant is an investment in cooler neighborhoods, healthier communities, and a more resilient Puerto Rico. Whether by planting a tree, caring for one already growing on your street, or inspiring someone else to value urban trees, everyone has a role to play. Our cities are calling for more trees, and every aspect of urban life, from public health and mobility to biodiversity, water management, and community well-being, benefits from them. One of the simplest and most powerful ways we can adapt to a changing climate and our call to action is to plant and care for trees. Best of all, this is something everyone can begin doing today.
