Featured Research

from universities, journals, and other organizations

A Tree's Response To Environmental Changes: What Can We Expect Over The Next 100 Years?

Date:
October 13, 2009
Source:
American Journal of Botany
Summary:
The many environmental issues facing our society are prevalent in the media lately. Our ecosystem is composed of a very delicate network of interactions among all species and the non-living environment. Predicting how each component of this complex system will respond to the many environmental changes sweeping the globe is a challenging problem today's scientists face. This study explores how increasing concentrations of atmospheric carbon dioxide may be affecting trees and, ultimately, affecting water and carbon cycles.

Forest in West Virginia. How will increasing concentrations of atmospheric carbon dioxide (CO2) be affecting trees and, ultimately, affecting water and carbon cycles?
Credit: Copyright Michele Hogan

The many environmental issues facing our society are prevalent in the media lately. Global warming, rainforest devastation, and endangered species have taken center stage. Our ecosystem is composed of a very delicate network of interactions among all species and the non-living environment. Predicting how each component of this complex system will respond to the many environmental changes sweeping the globe is a challenging problem today's scientists face.

Related Articles


A recent article by Dr. Abraham Miller-Rushing and his colleagues at Boston University published in the October issue of the American Journal of Botany explores how increasing concentrations of atmospheric carbon dioxide (CO2) may be affecting trees and, ultimately, affecting water and carbon cycles.

It is known that increasing concentrations of atmospheric CO2 affect the physiology and behavior of many organisms, and in plants, changes to the pores (stomata) on the surface of leaves are one example of these effects. Stomata allow air (containing CO2) to pass into the leaf while water vapor passes out of the leaf. Plants use carbon dioxide to produce sugars during the process of photosynthesis. With increasing concentrations of atmospheric CO2, stomatal density decreases while rates of photosynthesis increase. The decrease in stomatal density results in decreased water loss through the leaves.

"These changes in stomatal behavior and water use efficiency can, in turn, have large impacts on plants and can alter ecosystem-scale water and carbon cycling," Miller-Rushing said. "For example, soil moisture, runoff, and river flows might increase and drought tolerance in individual plants might improve."

The relationship between atmospheric CO2 concentrations and stomatal density is so constant over the long term that scientists are able to use stomatal density of fossilized leaves to determine historical atmospheric CO2 concentrations. However, short-term responses to changes in CO2 concentrations have previously been found to be much more variable, and very little concrete data exist on how long-lived organisms respond to changing CO2 concentrations. "We currently do not know how the anatomy and water relations of individual trees will respond to changes in climate and atmospheric concentrations of CO2 over their lifetimes," Miller-Rushing said. "Understanding these responses will be key to predicting how forests might contribute to changes in carbon and water cycles over the next 100 years."

Miller-Rushing and his colleagues examined the stomatal density on leaves, the length of the cells that surround the stomata (called guard cells), and the leaves' efficiency of water use (a measurement that compares the amount of carbon that is converted to sugar with the amount that passes through the stomata) in 27 trees growing at the Arnold Arboretum in Boston, Massachusetts for the past century. By examining several dried specimens from each plant that had been collected over the past hundred years, they were able to assess these characteristics in a temporal framework. During this period, global atmospheric CO2 concentrations increased by approximately 29%. Miller-Rushing and colleagues found that stomatal density declined while guard cell length increased in oaks and hornbeams, although these changes were not dependent on the magnitude of changes in CO2 concentrations. Intrinsic water use efficiency did not change significantly over time, suggesting that it may not respond to changes in CO2 concentrations over the lifetimes of individual trees, possibly because of compensating changes in stomatal density and guard cell size.

"This finding may have important implications for models that predict changes in future climate, carbon, and water cycles," Miller-Rushing stated. "We also demonstrated a new method that will allow researchers to investigate these questions in greater depth, namely by using herbarium specimens sampled repeatedly from the same trees, as is often done at botanical gardens."

As understanding the rippling impacts caused by various changes to the environment becomes increasingly more important, proper methodology to address these questions has become essential.


Story Source:

The above story is based on materials provided by American Journal of Botany. Note: Materials may be edited for content and length.


Journal Reference:

  1. Miller-Rushing et al. Long-term relationships among atmospheric CO2, stomata, and intrinsic water use efficiency in individual trees. American Journal of Botany, 2009; 96 (10): 1779 DOI: 10.3732/ajb.0800410

Cite This Page:

American Journal of Botany. "A Tree's Response To Environmental Changes: What Can We Expect Over The Next 100 Years?." ScienceDaily. ScienceDaily, 13 October 2009. <www.sciencedaily.com/releases/2009/10/091007091752.htm>.
American Journal of Botany. (2009, October 13). A Tree's Response To Environmental Changes: What Can We Expect Over The Next 100 Years?. ScienceDaily. Retrieved November 20, 2014 from www.sciencedaily.com/releases/2009/10/091007091752.htm
American Journal of Botany. "A Tree's Response To Environmental Changes: What Can We Expect Over The Next 100 Years?." ScienceDaily. www.sciencedaily.com/releases/2009/10/091007091752.htm (accessed November 20, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Thursday, November 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nations Pledge $9.3 Bn for Green Climate Fund

Nations Pledge $9.3 Bn for Green Climate Fund

AFP (Nov. 20, 2014) — Nations meeting in Berlin pledge $9.3 billion (7.4 bn euros) for a climate fund to help poor countries cut emissions and prepare for global warming, just shy of a $10bn target. Duration: 00:46 Video provided by AFP
Powered by NewsLook.com
What's The Point Of Climate Conferences?

What's The Point Of Climate Conferences?

Newsy (Nov. 20, 2014) — There's optimism about the U.N.'s climate conference in Paris next year, and if climate conferences past are anything to go off, that's notable. Video provided by Newsy
Powered by NewsLook.com
Giant Panda at Toronto Zoo Loves Somersaulting in the Snow

Giant Panda at Toronto Zoo Loves Somersaulting in the Snow

Buzz60 (Nov. 19, 2014) — A giant panda at the Toronto Zoo named Da Mao is celebrating the northeast snowfall by playing and tumbling in the snow in his outdoor enclosure. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Scientists Find Out What's Been Killing Millions Of Starfish

Scientists Find Out What's Been Killing Millions Of Starfish

Newsy (Nov. 18, 2014) — Scientists have found the cause of the biggest marine epidemic in history: the virus behind starfish wasting disease. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins