trees

A dirt pathway through a sunlight filled forest with tall, thin trees. A shrub is in the foreground.

How Many Tree Species are There in the World?

Katarina Samurović

A collaborative effort by a global tree scientist community has finally provided an answer to a long-standing puzzle about the total number of tree species on the planet.

Non-diverse tree populations like this orange grove can potentially make drought conditions worse. Photo: Cynthia Mendoza, USDA, Fresno Harlen Ranch in Fresno, CA, 2014, public domain.

New Findings on How Trees Impact Droughts

Katarina Samurović

Recently published research looked at the question of, "Instead of looking at how drought affects the forest, how might this go the other way around?"

Willow Oak in City Park. Photo: USGS, public domain.

Increasing Tree Cover Linked to Improved Community Mental Health

Elizabeth Borneman

Studies show that adults who live in a neighborhood that has 30% or more tree coverage have lower odds of experiencing psychological distress in their lifetime.

Tree Migration Direction Affected by Climate Change

Elizabeth Borneman

Ecologists have found that climate change, as it changes precipitation levels and temperatures, is causing trees to grow in different locations than they have traditionally taken root.