Fires Regenerate African Grassland

Natural grass fires are evidently more important for the ecology of savannahs than has previously been assumed. This is the finding of a study carried out in Etosha National Park in the north of Namibia. It is the first study to have investigated the complex interplay of the factors fire, competition, moisture and seed availability in relation to a grass species. Periodic fires in semi-arid regions can lead to older tufts of grass disappearing, thereby making room for younger grasses.

Writing in the Journal of Ecology, the researchers from the Helmholtz Centre for Environmental Research (UFZ), the University of Frankfurt am Main and the University of Cologne say that fire therefore plays an important role in regeneration. The findings are particularly significant for the management of semi-arid nature reserves, in which, in the absence of natural plant eaters, fires are the only practical means of renewing the grass canopy.

For the study, the researchers selected an area measuring 500 by 500 metres in Etosha National Park because it has one dominant grass species and because it was possible to rule out interference such as grazing and other human influences. Etosha National Park in the north of Namibia is the second largest nature reserve in Africa, measuring 20,000 square kilometers.

The temperatures in the semi-arid savannah fluctuate between 6 degrees centigrade in the winter and 35 degrees in the summer. The area under investigation is one of the driest areas in which plants can still grow, with annual rainfall of just 380 mm. That is less than the rainfall in the rain shadow of the Harz mountains.

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The Emerging Scientific Discipline of Aeroecology

In the history of science and technology, there is an infrequent combination of empirical discoveries, theories and technology developments converge that make it possible to recognize a new discipline. Past examples include marine biology, biomechanics and astrobiology with more recent developments of nanotechnology and bioinformatics – all disciplines that are now well established in the lexicon of modern science and technology.

Aeroecology is one such emerging discipline, says Thomas Kunz, Boston University professor of biology and director of the Center of Ecology and Conservation Biology and the lead author of "Aeroecology: probing and modeling the aerosphere," a research report in Integrative and Comparative Biology, based on a symposium sponsored by the Society for Integrative and Comparative Biology.

Kunz, who is best known for his extensive research on bats, explains that aeroecology embraces and integrates the domains of atmospheric science, earth science, geography, ecology, computer science, computational biology, and engineering.

The unifying concept that underlies aeroecology is its focus on the planetary boundary layer of the Earth's atmosphere, or aerosphere, which supports the myriad of airborne organisms that, in large part, depend upon this natural environment for their existence. Organisms that use the aerosphere, specifically arthropods, birds and bats, are also influenced by an increasing number of anthropogenic or man-made conditions and structures, notably lighted towns and cities, air pollution, skyscrapers, aircraft, radio and television towers, plus a recent proliferation of communication towers and wind turbines that dot the Earth's landscape.

In addition, human-altered landscapes increasing are characterized by deforestation, intensive agriculture, urbanization, and assorted industrial activities that are rapidly and irreversibly transforming the quantity and quality of available terrestrial and aquatic habitats which airborne organisms rely upon. These conditions are known to influence navigational cues, sources of food, water, nesting and roosting habitats--factors that can, in turn, alter the structure and function of terrestrial and aquatic ecosystems and the assemblages of organisms.

Similarly, "climate change and its expected increase in global temperatures, altered circulation of air masses, and effects on local and regional weather patterns are expected to have profound impacts on the foraging and migratory behavior of insects, birds and bats," noted Kunz.

"In contrast to organisms that depend strictly on terrestrial or aquatic existence, those that routinely use the aerosphere are almost immediately influenced by changing atmospheric conditions ( e.g. winds, air density, precipitation, air temperature) sunlight, polarized light, moonlight and geomagnetic and gravitational forces," the report states.

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Try Eco-Tourism in Hawaii

Hawaii is my favorite place on Earth -- I've visited twice.

Everyone should go at least once in their lives. Now, there are alternatives called eco-tourism that will help ensure Hawaii's paradise for generations to come.

According to the Hawaii Ecotourism Association, ecotourism is nature and culture based tourism that is ecologically sustainable and supports the well being of local communities. Commercial entities have become a positive influence on the environment because they promote a tourism industry that is environmentally and culturally sensitive while increasing profits.

HawaiianBeachRentals.com offers Kauai vacation rentals that are environmentally friendly.

Kauai is the oldest and northernmost of the main Hawaiian islands. It is known as the Garden Isle.

The spirit of the land is referred to as “aina” in Hawaii. Kauai condo rentals and hotels are sensitive to this “aina” because they are built with special care to have the least impact possible on the precious local land and wildlife.

“We have traditionally specialized in providing our customers with alternative trips to Hawaii allowing them to stay in unique places and helping them coordinate the details of their dream vacation, be it romantic, active or relaxation focused," says Jeff Berzolla of Hawaiian Beach Rentals. "Also, our staff enjoys living and playing in Hawaii. Time off is often spent visiting the units we rent to our customers, whether they’re Maui vacation rentals or condos on Kauai, to better understand the Islands and the beautiful paradise we share with the world.”

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Human Preference for Other Species Could Determine Whether They Survive

As humans exert ever-greater influence on the Earth, their preferences will play a substantial role in determining which other species survive. New research shows that, in some cases, those preferences could be governed by factors as subtle as small color highlights a creature displays.
In the case of penguins, mostly black-and-white flightless birds that live predominantly in the Southern Hemisphere, those most popular with humans appear to be the ones that display markings of warm colors such as red, orange or intense yellow, said David Stokes, a conservation biologist at the University of Washington, Bothell.

He and his undergraduate students calculated the popularity of various species by studying photographs in four large-format photograph books about penguins. Decisions about how many and which photographs to use and how large to make them presumably were made by the books' editors based on their own preferences or on their beliefs of what would appeal to the book-buying public.

"Penguins are lucky because they are popular with people, especially right now. But that's not true of 99.9 percent of the species out there," Stokes says. "Even the penguin species I found to be among the least appealing to people are tourist attractions."

Tops on the list are the Emperors, featured in the film March of the Penguins, and their close cousins the King penguins. Second are crested penguins, including Rockhoppers and Macaroni.
Species at the bottom of the list are Adelie, Yellow-eyed and Little Blue. Stokes was surprised by the relative lack of popularity of Adelie penguins because that species is probably the most familiar to the public.

There are 17 penguin species, and in the past some were hunted for food or boiled to extract their oil. Some species now struggle to survive climate change, changing food patterns and encounters with humans or human activity, such as oil drilling at sea.

The species are fairly similar, with some larger and some smaller, Stokes says. But the ones that appear to be most popular are the ones that display the warmest colors in the upper body, the neck and head. He likened the effect to that of a man in a tuxedo pinning on a red carnation.

No 'cuteness factor'

Unlike some other types of animals, human preference for particular penguin species does not seem to be driven by a "cuteness" factor.

The four books Stokes examined were published in the last decade and were aimed at the popular adult audience. He eliminated photographs from consideration when factors other than the penguins themselves -– the surrounding landscape, for example, or accompanying humans – could have played a role in their selection. He was left with 304 pictures that clearly showed specific penguin species, and he concluded that a species' popularity wasn't because it was easy to get to, or because it had the largest population, or because of similar factors.

"I went to great lengths to ensure that what I was looking at was a purposeful set of pictures and not one just based on logistics," he says. The popularity rankings were similar across all four books, he added, which suggests that human preferences could be widely shared.

The work has been published in the online edition of the journal Human Ecology, and will appear in an upcoming print edition.

Color is not the only factor that determines a species' attractiveness to humans. Characteristics such as size and neoteny – the retention of babyish physical traits such as large eyes and large head – also can play major roles for some animals. Pandas, zebras and elephants, for example, are black and white or gray but are highly preferred by humans. Millions of insects and the countless slimy invertebrates that occupy the oceans are likely not as lucky, Stokes says.

"The work pretty conclusively shows there is a large difference of appeal among organisms, even among closely related organisms," he says. "For different kinds of organisms, different qualities seem to cause differences of appeal."

The work is a signal to conservationists to be mindful of the role of public popularity, and what might cause it, when making decisions about how to deal with various species, even invasive species.

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