ecology

Forest Regrowth In The Amazon | Earth Wise

January 20, 2020 By EarthWise Leave a Comment

The Amazon is the largest tropical rainforest in the world. It covers an area approximately equal in size to the lower 48 states, and is home to an estimated 10% of the world’s biodiversity and 15% of its freshwater. These so-called “lungs of the planet” provide many important global ecological services, including carbon storage, and regulating air quality and climate.

Deforestation in the Amazon exploded in the 1970s and remains one of its biggest threats today. Since the 1970s, more than 20% of the Amazon rainforest has been cleared. Cattle ranching, soy and palm plantations, logging, and climate change are some of the biggest drivers of deforestation.

Now, according to a new study recently published in the journal Ecology, the regrowth of Amazonian forests following deforestation may happen more slowly than previously thought. These findings could have significant impacts on climate change predictions as the ability of forest regrowth in the Amazon – so-called secondary forests – may have been overestimated. The research, which was conducted in Bragança, Brazil and includes two decades of forest monitoring, reveals that climate change and the wider loss of forests could be hampering regrowth.

After 60 years of regrowth, the research team found that secondary forests only held 40% of the carbon when compared with forests undisturbed by humans. Secondary forests also take less carbon from the atmosphere during periods of drought, and climate change is increasing the number of drought-years in the Amazon. (During their 20 years of monitoring, the researchers also found biodiversity levels in secondary forests were only 56% of those seen in undisturbed forests).

More long-term studies are needed to better understand the impacts of reforestation efforts.

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Amazon forest regrowth much slower than previously thought

Photo, posted September 6, 2009, courtesy of Nao Lizuka via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Road Salt Pollution

January 8, 2020 By EarthWise 1 Comment

Mirror Lake is a popular recreational lake located in the Village of Lake Placid. It is the most developed lake within the Adirondack Park, which is a publicly protected area that is actually larger than Yellowstone, Yosemite, Glacier, and Grand Canyon National Parks combined.

New research has revealed that road salt runoff into Mirror Lake is preventing natural water turnover which poses a risk to the balance of its ecology. The study, which was published in Lake and Reservoir Management, found that road salt runoff is preventing spring mixing of the water column. This creates more anoxic water conditions, meaning there is less oxygen in the water, and limits the ability of the habitat to support the native lake trout.

Mirror Lake is the first lake in the Adirondack Park to show an interruption in lake turnover due to road salt. Many lakes in northern climes experience so-called “dimictic turnover”, which is a natural process where wind and less stratified water conditions of spring and fall allow mixing of the water column that redistribute oxygen and nutrients throughout the lake. High levels of surface-water chloride introduced into the lake from road salt runoff inhibit the mixing of the water column.

The lack of mixing and oxygenation is bad news for fish species such as lake trout, which require cold, oxygenated water to survive. It may also put the lake at a greater risk of algal blooms.

Mirror Lake is small, surrounded by concentrated development, and receives the direct discharge of stormwater. So, it is particularly vulnerable to road salt contamination. Other lakes elsewhere in New York may experience similar conditions. The researchers are confident that natural turnover conditions could be restored to the lake if road salt application in the watershed is reduced.

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Road salt pollutes lake in one of the largest US protected areas, new study shows

Photo, posted January 5, 2018, courtesy of MTA of the State of NY via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Eco-Friendly Agriculture

October 21, 2019 By EarthWise Leave a Comment

Modern agriculture has steadily destroyed native grasslands, among other ecosystems. In fact, farming is one of the most ecologically destructive things that humans do. But we do have to eat. In response, there is a growing movement for agrarian reform, from grain farming on the prairie, to agroforestry, to raising livestock more sustainably. Efforts are accelerating to develop a kinder, gentler agriculture adapted to a changing world.

One such effort has come from the Land Institute, an organization in Kansas that works on natural systems agriculture, which seeks to retain the ecological stability of the prairie with its perennial seed plants along with a grain and seed yield comparable to that from annual crops.

After four decades of effort, the institute has introduced its first commercial grain, a trademarked variety called Kernza. Kernza is a domesticated perennial wild grass – a so-called intermediate wheatgrass – that has a long, slender head that resembles wheat seeds. People describe its taste as sweet and nutty. Kernza is already being made into a cereal called Honey Toasted Kernza by Cascadian Farms. Patagonia Provisions – a spin-off from the clothing company – is making beer from the new grain.

Although Kernza is already being grown and sold commercially, it is not yet ready for prime time. Last year, there were only about 1,000 acres in cultivation and the yield is only a third to a tenth of the yield of wheat.

Developing a sustainable perennial polyculture of edible plants would have major benefits such as not having to plow every year, plants developing large root systems that can reach water far beneath the surface and, without annual plowing, having soil carbon remain in the ground.

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With New Perennial Grain, a Step Forward for Eco-Friendly Agriculture

Photo courtesy of Cascadian Farms/General Mills.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Global Fisheries

April 12, 2019 By EarthWise Leave a Comment

A Rutgers University-led study published in the journal Science has shown that climate change has taken a toll on many of the world’s fisheries and that over fishing has magnified the problem.

Seafood has become an increasingly important source of nourishment as the global population grows, especially in coastal, developing countries where it provides as much as half of the animal protein eaten. More than 50 million people worldwide work in the fisheries industry or subsist on fisheries.

Scientists at Rutgers and the National Oceanic and Atmospheric Administration studied the impact of ocean warming on 235 populations of 124 species in 38 ecological regions around the world. Species included fish, crustaceans such as shrimp, and mollusks such as scallops. They combined data on fisheries with ocean temperature maps to estimate temperature-driven changes in the sustainable catch over 8 decades. The data covered about one-third of the global catch.

According to the study, ocean warming has led to an estimated 4.1% drop in sustainable catches, on average around the world, for many species of fish and shellfish from 1930 to 2010. In five regions that include the East China Sea and the North Sea, the estimated decline was 15 to 35%.

The researchers recommend that fisheries managers eliminate over fishing, rebuild fisheries, and account for climate change in fisheries management decisions. Over fishing provides a one-two punch to fisheries facing warming waters. It not only makes fisheries more vulnerable to ocean warming but continued warming will also hinder efforts to rebuild over fished populations.

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Climate Change Shrinks Many Fisheries Globally, Rutgers-Led Study Finds

Photo, posted April 23, 2011, courtesy of Derek Keats via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Infertility

March 8, 2019 By EarthWise Leave a Comment

Many of us are all too familiar with the effects of climate change. Our changing climate, as a result of our actions, is leading to rising global temperatures, biodiversity loss, ocean acidification, wildfires, more weather extremes like floods and droughts. But a lesser known effect of climate change could lead to frightening consequences: infertility.

According to researchers at the University of Liverpool, rising temperatures could make some species sterile and lead them to succumb to the effects of climate change far earlier than currently thought. Their work was recently published in the journal Trends in Ecology and Evolution, and it was produced in collaboration with scientists from the University of Leeds, University of Melbourne, and Stockholm University.

Biologists and conservationists are trying to predict where species will be lost due to climate change so that suitable reserves can be established in other locations. But the problem is that most data on when temperature will make an area unlivable for a species is based on its ‘critical thermal limit’ or CTL. This is the temperature at which a species would collapse, stop moving, or die.

The authors of the article fear that the impact of climate change on species survival is being underestimated. Because rather than zeroing in on lethal temperatures, the scientists argue the focus should be on the temperatures at which organisms can no longer breed. Extensive plant and animal data suggest organisms lose fertility at a lower temperature than their CTL.

The scientists have proposed a new fertility-based metric to gauge how organisms function as temperatures climb: Thermal Fertility Limit or TFL. Understanding when a species will cease to reproduce will certainly help conservation measures.

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Climate change and infertility — a ticking time bomb?

Photo, posted August 11, 2013, courtesy of Mike Lewinski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hippo Waste And Fish

September 10, 2018 By EarthWise Leave a Comment

Agricultural and sewage pollution can cause low-oxygen conditions and fish kills in rivers. A new study published in Nature Communications reports that hippo waste can have a similar effect in Africa’s Mara River, which passes through the world renowned Maasai Mara National Reserve of Kenya and is home to more than 4,000 hippos.

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The Ecology Of Dust

January 19, 2018 By EarthWise Leave a Comment

It isn’t something we think about very often, but dust is a connector of ecosystems around the world. Dust carries various minerals and nutrients to places where such things are in very scarce supply. This includes the oceans of the world as well as many forests and other ecosystems. For example, phosphorus-bearing dust carried from the Gobi Desert is essential to the growth of giant redwoods in California’s Sierra Mountains.

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Disappearing Kelp Forests

January 9, 2018 By EarthWise Leave a Comment

In recent decades, ocean temperatures in many places have warmed by nearly 3 degrees Fahrenheit. An effect of this warmer water is the decimation of what were once luxuriant giant kelp forests in eastern Australia and Tasmania. There used to be thick canopies covering much of the region’s coastal sea surface, but they have wilted in the intolerably warm and nutrient-poor water.

Learning From Fire

December 28, 2017 By EarthWise Leave a Comment

The Tubbs Fire was the huge wildfire that burned parts of Napa, Sonoma and Lake counties in Northern California in October. Between that fire and several smaller ones going on at the same time, at least 43 people died and over 8,400 homes and buildings were destroyed. The Tubbs Fire alone burned over 36,000 acres. The even larger December wildfires in Southern California scorched hundreds of thousands of acres in multiple counties.

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Nature Is Satisfying

May 16, 2017 By EarthWise

For most of us, a day spent in the mountains, the woods, or at the beach always seems like a good day. Communing with nature tends to make us feel better.

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Did People Create The Sahara Desert?

April 25, 2017 By EarthWise

One of the arguments some people make when discussing human causes of climate change is that people can’t cause such massive changes. However, there is a long historical record of human-driven ecological and climatic change in Europe, North America and New Zealand, among other places.

The Great Salt Lake Is Shrinking

January 9, 2017 By EarthWise

Utah’s Great Salt Lake is the largest salt water lake in the Western Hemisphere and is the largest body of water in the United States after the five Great Lakes. When the pioneers first arrived in the area back in the middle of the 19th century, the lake spread across about 1,600 square miles. Now, the lake covers an area of only about 1,050 square miles, a reduction of about 35%.

The Threat Of Bushmeat Hunting

November 22, 2016 By WAMC WEB

A recent study has identified the steep decline of more than 300 species of mammals as a result of unregulated or illegal hunting. Humans are consuming many of the world’s wild mammals to the point of extinction.

A Refuge For Black Spruce

August 23, 2016 By WAMC WEB

In the Canadian province of Quebec, a study of more than 26,000 trees across an area the size of Spain forecasts winners and losers in a changing climate.

Lessons From The Forest

July 29, 2016 By WAMC WEB

For more than half a century, scientists have converged on Hubbard Brook Experimental Forest in New Hampshire’s White Mountains to explore how forest ecosystems work. The site was established by the U.S. Forest Service to study the relationship between forests and New England’s water supply. In the 1960s, inquiry was expanded to include ecology, biogeochemistry, and studies of birds and other animals.

Natural World Heritage Sites

May 5, 2016 By WAMC WEB

Natural world heritage sites exemplify the world’s greatest areas of natural beauty, ecology, geology, and biodiversity. They are recognized internationally for their value as places with significance that is “so exceptional as to transcend national boundaries and be of common importance for present and future generations of all humanity.” Many of these areas also are a vital source of food, fuel, and water for rural communities, and provide a revenue stream for national economies through tourism and recreation. The livelihoods of some 11 million people are directly dependent on these areas.

Ecology And Designing Future Cities

January 4, 2016 By WAMC WEB

When most people hear the word ‘ecology’ – chances are it conjures up images of scientists working in distant, wild landscapes, such as old growth forests or remote mountain lakes. Increasingly, however, ecological studies are focused on urban and suburban areas.