Tag Archives: ecology

Shining new light on trees and CO2news_reich_main

How much do trees vary in the way they suck carbon dioxide from the air and use it to make roots, trunks, branches and leaves? The answer to that question is an important one because it has a huge impact on our ability to predict how destroying or creating forests influences climate change. And the correct answer is a surprising one, according to two related studies published in the Proceedings of the National Academy of Sciences this week by University of Minnesota forest ecologist Peter Reich and colleagues in Minnesota, Arizona, Australia, China, Poland and Germany.

Conventional models used to assess the impact of forests on greenhouse gas concentrations in the atmosphere assume that the way trees use carbon to build roots, leaves and trunks is fairly constant across a range of conditions — that is, that trees everywhere devote the same fraction of new growth to each component and that components have the same durability everywhere. However, analyzing massive amounts of data gathered from around the globe, Reich and colleagues documented predictable differences in key properties of forests across north-south climate gradients.

“These findings both advance our understanding of how trees vary and provide useful tools for making earth system models more accurate,” said Reich, a Regents professor and distinguished McKnight University professor in the College of Food, Agricultural and Natural Resource Sciences and resident fellow of the Institute on the Environment. “[Most of all, they dramatically improve our ability to accurately assess the impact of forests on climate change and vice versa.]”

In one paper, the scientists addressed the question of whether trees invest more heavily in building roots to enhance uptake of water and nutrients in cold climates, where these resources are scarce. Using data from more than 6,000 forests in 61 countries, the researchers discovered that cold-climate forests tend to build more roots and less leaves than those found in warmer climates. This information will improve scientists’ ability to estimate how much carbon trees store worldwide.

The second study looked at how the amount of time cold-climate evergreens such as spruce, fir and pine hang onto their needles varies with climate. Until now, research looking at the flow of carbon through ecosystems generally assumed that evergreens like spruce and pine keep their needles for an average of two years pretty much everywhere. These new findings, gathered from more than 125 sites in North America and Europe, paint a far different picture. The researchers found that the needles of evergreen trees such as spruce and pine in the cold, far north of Canada and Scandinavia last longer but have a lower capacity for capturing carbon than do needles of trees in warmer (relatively speaking) climates such as Minnesota or Germany. These north-south geographic patterns are similar enough among pines and spruces and Europe and North America to enable their incorporation into global vegetation and earth system models, resulting in more accurate projections of forest productivity, carbon flow and how forest are likely to change in the future.

The research involved multiple partners, including a large IonE-sponsored initiative, the Plant Data Synthesis project, which seeks to bring together massive amounts of data from around the world in search of big-picture patterns related to how trees and forests function.

“By improving our understanding of how forests vary from tropics to temperate zone to the polar edges of boreal forest, we hope to provide fundamental advances to basic science and new tools for better modeling forest growth and climate regulation today and into the future,” Reich said.

The University of Minnesota’s Institute on the Environment seeks lasting solutions to Earth’s biggest challenges through research, partnerships and leadership development. For more information, visit environment.umn.edu.

Photo by Jim Brekke (Creative Commons / Flickr)

Go Minnesota NatCap!Natural Capital

Policy makers, land managers, and other stakeholders confront a dizzying array of environmental decisions. How do we best manage our natural resources? Where should we invest in conservation? Do we need stricter regulation of development or industry?

The Natural Capital Project, a core program of the Institute on the Environment, develops innovative tools and approaches to inform these important questions. Starting this year, the Minnesota team will add three full-time research positions — a lead scientist, an ecologist and an economist. The growing NatCap presence at IonE will enhance the program’s ability to meet increasing demand for data and tools that quantify the values of natural capital. Continue reading

Collaboration with consistency: The Nutrient NetworkNutNet India

When scientists ask big questions, it’s always difficult to get the big answer. When scientists ask big ecological questions that require synthesizing data from a variety of geographical locations and different research protocols, it can seem downright impossible.

In the case of the Nutrient Network, a project that recently began receiving funding from the Institute on the Environment, that frustration with such scientific incongruence fueled a solution. Continue reading

Not Toba’s faultmalawi barge

Tom Johnson, a University of Minnesota Duluth Regents professor and Institute on the Environment resident fellow, knew his work on Lake Malawi in 2005 would yield significant scientific discoveries. Now, eight years later, he and his colleagues have announced research that impacts our knowledge of the near extinction of the human race. They have determined that 75,000 years ago, the Toba volcanic eruption in Sumatra did not cause a volcanic winter or the dramatic drop in human population in Africa, as some anthropologists had proposed.
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Phenology & fun April 5-7Flowers

It always seems that the more extreme the seasons, the more extreme the opinions about them tend to be. Here in Minnesota, as spring arrives and the cold snowy winter says goodbye, we hear a multitude of opinions, ranging from “I love winter!” to “Finally!” to “I wish it were summer all year long.”

Then we see changes occurring around us, such as the beginning of mosquito season, flowers blooming, the return of the geese, the end of cold and flu season.
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Frontiers: Sound ecologyEcology of Sound

What is noise, and how does it affect the natural world? These are among the questions Mark Pedelty, IonE resident fellow and College of Liberal Arts associate professor, posed at his February 27 Frontiers in the Environment seminar, “Sound Ecology: The Environmental Effects of Mechanical Noise and Human Music.”

Pedelty is hoping to influence land development policy to take the effects of mechanical and human noise into account. For example, he noted that some songbirds sing louder and at a higher pitch in urban landscapes, and industrial noise has been shown to inhibit foraging and reproduction in certain frog species.
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