The exact science of tree sap transport has puzzled plant physiologists for many years. Sap’s migration throughout tree trunks and branches is linked heavily to transpiration, the movement and subsequent evaporation of moisture from plants. As carbon dioxide diffuses inward from the air to plant leaves, a vapor pressure deficit between the leaf interior and surrounding atmosphere causes evaporation. This generates tension within leaf cell walls that is then transmitted via sap to tracheids — conductive hollow wood cells with vertical grooves that comprise the trunk, stem, and branches of trees and are collectively called sapwood. The resulting negative sap pressure draws water from roots to leaves, sometimes to heights of over 300 feet. 

A global biodiversity collapse is imminent unless we take urgent, concerted action to reverse species loss in the tropics, according to a major scientific study in the prestigious journal Nature.  

Rice University scientists have released the first results of extensive water sampling in Houston after the epic flooding caused by Hurricane Harvey. They found widespread contamination by E. coli, likely the result of overflow from flooded wastewater treatment plants.

Add just enough fertilizer, and crops thrive. Add too much, and you may end up with contaminated surface and groundwater.

Scientists studying winter flocks of golden-crowned sparrows at the UC Santa Cruz Arboretum have discovered surprisingly complex social behavior in these small migratory birds. A new study reveals that the sparrows have different ways to assess dominance status depending on whether the interaction is with a familiar bird or a stranger.

Research shows that Kodiak brown bears that sync their stream-to-stream movements to salmon spawning patterns eat longer and more than bears that don’t, with one bear in the study consuming greater than 2 tons of fish in one summer.

Sheltered pockets of cooler and more variable conditions in the British countryside may help native species of flora and fauna survive warming temperatures caused by climate change, researchers have found.

An organic formulation containing honeybee pheromones has been found to safely repel elephants, offering promise for a new strategy to prevent the world’s largest land animals from destroying crops or causing other damage in areas where humans conflict with elephants, according to a study published July 23, 2018 in Current Biology.

Current crop yields could provide nutritious food for the projected 2050 global population, but only if we make radical changes to our dietary choices, a new study shows.

Colorful, hardened algae that dot the ocean floor from Alaska to Mexico often set the tone for which plant and invertebrate species inhabit a given ecological community.