By Ed Stoddard
KRUGER NATIONAL PARK, South Africa (Reuters) - South Africa's Kruger National Park is littered in places with the trunks of trees uprooted and stripped of bark by a surging population of elephants, a frequent sight in the reserve.
Africa's elephants are still threatened by poachers seeking to kill them for their ivory tusks but in several southern states populations have rebounded, helped by conservation policies and the remote locations where many of the herds live.
The numbers are now so big that some countries say the world's largest land mammal is causing too much damage to crops, threatening the livelihoods of poor subsistence farmers and the populations of other species including birds, bats and woody plants in forests uprooted by elephants.
Zimbabwe and Namibia have asked for a global ban on ivory trade to be lifted so that they can use the proceeds of national stockpiles of tusks to fund conservation and support communities living near elephants.
"Elephants are regarded as a liability and economic cost to rural communities, who suffer crop losses, other damages and lose human lives," Namibia's proposal says. Its population has increased to 20,000 from 7,500 the past two decades.
The request to sell stockpiles, collected through seizures of contraband, natural mortality in the wild and the shooting of problem animals, will be considered at a meeting of the U.N.'s Conference on International Trade in Endangered Species (CITES) in Johannesburg from September 24 to October 5.
The ban on trade in ivory products was imposed in 1989 in response to a wave of poaching, though domestic trade has remained legal in a number of countries including China. The United States in July imposed a near-total ban on domestic ivory sales within its borders.
Opponents are concerned that if CITES allows ivory to be traded, even from stockpiles and as a one-off, it would send a signal that it is socially acceptable, which could spur demand and further poaching.
Ivory is particularly coveted in Asia where it is used for carving and jewelry. Botswana, Namibia and Zimbabwe were given permission to sell stockpiles to Japan in 1999 and were joined by South Africa in 2008 in a sale to China and Japan.
A June 2016 study by the U.S. National Bureau of Economic Research found that the 2008 sale likely led to an increase in elephant poaching.
It noted an estimated 71 percent increase in ivory smuggling out of Africa "while corresponding patterns are absent from natural mortality and alternative explanatory variables. These data suggest the widely documented recent increase in elephant poaching likely originated with the legal sale."
Poaching has skyrocketed in the past decade in much of the continent to feed the illicit market, lending a new sense of urgency to campaigns to completely close the trade for good.
For their request to pass, Zimbabwe and Namibia will need the support of two-thirds of the 183 member states of CITES.
South Africa Environment Minister Edna Molewa told Reuters that her country and others in southern Africa would support the Namibian and Zimbabwean proposals because the ivory sales were needed to pay for the ecological and social costs of large elephant populations.
"If you look at the communities that are bearing the brunt of living with these animals, their ecological systems are degraded and they lose food security and grazing lands," she said.
She said "we are quite optimistic" the proposals would pass but expected tough negotiations.
There is expected to be significant opposition from most western countries, some NGOs and African countries including Kenya, which along with others has made a separate proposal to CITES to keep the trade ban firmly in place.
Sport hunting of elephants is permitted in some countries such as South Africa and Zimbabwe and hunters are allowed to keep the tusks as trophies.
But in Kenya, where elephants cannot be owned and where any hunting is forbidden, the animals are seen as a bigger draw for tourists wanting to see them in the wild. Kenya and Gabon, which has large areas of national park and is fighting a growing battle with poachers, have burnt ivory stockpiles.
And while elephant populations are stabilizing in southern Africa where conservation policies are stronger, in east and central Africa, poaching is rife and the numbers are down.
A census by Elephants Without Borders, a conservation group, found numbers of Savanna elephants - which favor more open habitat - fell 30 percent between 2007 and 2014 to 350,000.
Africa's other species, the forest elephant, will need a century to recover from poaching because of its slow birth rate, and numbers around 70,000.
"A BIT SELFISH"
Zimbabwe says its elephant population has stabilized at 80,000. Its proposal says elephant populations exceeding 0.5 per km have a detrimental impact on woodlands and other species.
However, scientists say the damage done by elephants is being exaggerated and that they are crucial for healthy ecosystems because their dung disperses seeds and fertilisers and they create habitats for smaller creatures through foraging.
"Elephants are a key driver in maintaining biodiversity," said Sam Ferreira, a South African National Parks ecologist.
"No species in the Kruger has ever gone extinct because of elephants."
Since culling was halted at Kruger in 1994, the elephant population has swollen from around 8,000 to 17,000 - and other animals have not suffered, he said.
In Chobe National Park in northern Botswana, where the number of elephants has risen to 130,000 from 30 in 1930, scientists say antelope species such as impala have benefited from the removal of trees by elephants as they favor shorter vegetation. This in turn has boosted the populations of predators such as lions.
There is agreement, however, that elephants in Namibia and Zimbabwe are making life hard for the humans living nearby.
Zimbabwe's Campfire Association say elephants eat around 18 percent of the crops in the poor communities where the NGO works. It says people have been killed by then, often when subsistence farmers come across the animals in their fields.
Cash-strapped Zimbabwe, which has a 70 tonne ivory stockpile worth $35 million, says ivory trade is the only way to pay for protecting its elephants and to give rural communities an economic incentive for living near the animals.
Nevertheless, conservationists say Zimbabwe and Namibia should not be given special treatment.
"We do recognize that Zimbabwe and Namibia's elephants populations are in better shape than those elsewhere in Africa," said Susan Lieberman, vice president for International Policy at the Wildlife Conservation Society.
"But it's rather short-sighted and a bit selfish for them to request to sell their ivory, knowing full well that it will further stimulate poaching and trafficking from other populations. The global community needs to see this as an Africa-wide issue."
(Additional reporting by MacDonald Dzirutwe in Harare; editing by Anna Willard)