February 18, 2011 – By Robin Comita
In 2010, several scientists set out to study the impact of global warming on the iconic California redwoods. Studies have shown that the redwoods and sequoias have suffered with the decline in fog cover. Although the trees have survived since dinosaurs roamed the earth, only recently have they undergone a drastic rise in temperature and vast increase of carbon dioxide in the atmosphere. Scientists are concerned that as more water evaporates from the tree’s leaves, the monolithic redwoods will not be able to pump enough water to the tree tops and may not survive.
Inside the redwood is an intense hydrologic system unlike any other organism’s on earth. The trees have to efficiently transport water from their roots to the towering, sometimes 300 foot tall, tops of the trees. An impressive system for scientific study and analysis as redwoods can live for hundreds of years. Some of the California redwoods in this study are older than the medieval cathedrals in Europe.
The study involves trees from near the Oregon border to Santa Cruz County, and spreads across numerous state parks. The trees have been studied to the most minute detail; scientists even estimate the number of leaves and cones on each tree. Height and width are measured, including the length and width of bark and branches hundreds of feet above ground.
In order to collect this data, the research team hoists ropes which attach them to the redwoods, then climb to the very top. Next, trees are allotted numerous sensors which measure humidity, temperature, air pressure, rain, wind, light, and fog. The data collected by these devices will help scientists determine which changes in climate corollate most directly to changes in the tree’s health and growth.
Samples are also taken from the tree’s core and studied in a lab. A redwood’s tree rings can reveal its age and any significant weather changes that occurred in its lifetime while offering up other important clues about its history. 3D models are created on computers to help scientists predict the potential effects. Data will be taken again every three years, though the scientists hope the study lasts a hundred years or more. Data like they are collecting is unprecedented in scientific studies of the trees and could prove incredibly valuable in the near and more distant future. By 2100, some scientists have projected such immense climate change that the trees would no longer survive in this habitat.
Bases for these hypotheses are rooted in weather analysis and fog measurements from the area. Fog cover has decreased 33% over the past century and the redwoods have not responded favorably to the change. Redwoods rely on the coastal fog for an important percentage of their water intake. Similarly, atmospheric carbon dioxide has increased 30% in the past 150 years. Studies have shown that the trees growth is stunted by warm weather, and carbon dioxide reduces the annual rainfall while lowering precipitation and causing increased temperatures. Scientists do not know how the trees will respond, but many hope that the studies incite positive change.
With sufficient data, participating researchers hope to shed light on how climate change is affecting the infamous redwoods and sequoias. As awareness of the issue rises, they hope political action and governmental attention increase as well. Big changes will need to occur to ensure the redwoods survive hundreds of years from today. Controlled fires, wider redwood habitat preservation, and planting trees are all encouraged gestures which could increase their potential to survive. In roughly two years, these scientists will return to collect more data and draw further conclusions regarding the health of California’s redwoods.