LUSAKA - An invasive shrub is upsetting the ecological balance of national parks in Zambia's Kafue Flats and could drive away tourism.  A study by the Environmental Council of Zambia (ECZ), released last month (20 September), shows that the weed Mimosa pigra has covered around 2,900 hectares of the Kafue Flats.  It is interfering with the ecosystems by blocking access to water for animals and birds and displacing animals by reducing available habitat.

OTTAWA - While there has been much talk that Arctic trade routes will open up as northern ice melts, shipping companies and experts say using the fabled Northwest Passage through Canada's Arctic archipelago would be too difficult, too dangerous and totally impractical.  In theory, the idea is tempting -- the passage cuts the distance between Europe and the Far East to just 7,900 nautical miles, from 12,600 nautical miles through the Panama Canal.

PASARGADAE, Iran - For the people protesting against it, a new dam near these sun-drenched ruins may be more than an environmental upheaval: in it they scent an affront to the country's pre-Islamic identity.  For 2,500 years, the tomb of Cyrus the Great has stood on the plain at Pasargadae in southern Iran, a simple but dignified monument to a king revered as the founder of the mighty Persian empire. But some fear the dam and reservoir pose a threat to the ancient structure.

BRASILIA (Reuters) - Brazil's environment minister said on Wednesday the international community was failing to honor pledges to help protect the Amazon and other tropical forests but that her government rejected specific deforestation targets.

Marina Silva, a former rubber tapper and activist, said a 50 percent reduction in deforestation over the past two years showed Brazil's increased control mechanisms were working.

Ensuring a long-term reduction by changing the economic development model of the Amazon required foreign help, Silva said in an interview at her office in Brasilia.

"We don't want charity, it's a question of ethics of solidarity," said Silva, who defended the Amazon in the 1980s alongside legendary conservationist Chico Mendes.

VANCOUVER, British Columbia - Wet weather has thwarted a Canadian plan to stem the spread of tree-killing pine beetles eastward through the Rocky Mountains by burning an Alberta forest near Banff National Park, an official said on Wednesday.

The province of Alberta had planned to burn about 80 square kilometers of trees last week and it is now too late to make the attempt this year, said Duncan MacDonnell, a spokesman for the province's Sustainable Resource Development ministry.