When tree planting actually damages ecosystems



Giraffes prefer the open space and scattered trees of the African savanna.
Volodymyr Burdiak/Shutterstock

Kate Parr, University of Liverpool and Caroline Lehmann, University of Edinburgh

Tree planting has been widely promoted as a solution to climate change, because plants absorb the climate-warming gases from Earth’s atmosphere as they grow. World leaders have already committed to restoring 350m hectares of forest by 2030 and a recent report suggested that reforesting a billion hectares of land could store a massive 205 gigatonnes of carbon – two thirds of all the carbon released into the atmosphere since the Industrial Revolution.

Many of those trees could be planted in tropical grassy biomes according to the report. These are the savannas and grasslands that cover large swathes of the globe and have a grassy ground layer and variable tree cover. Like forests, these ecosystems play a major role in the global carbon balance. Studies have estimated that grasslands store up to 30% of the world’s carbon that’s tied up in soil. Covering 20% of Earth’s land surface, they contain huge reserves of biodiversity, comparable in areas to tropical forest. These are the landscapes with lions, elephants and vast herds of wildebeest.

Gorongosa, Mozambique. The habitat here is open, well-lit and with few trees.
Caroline Lehmann, Author provided

Savannas and grasslands are home to nearly one billion people, many of whom raise livestock and grow crops. Tropical grassy biomes were the cradle of humankind – where modern humans first evolved – and they are where important food crops such as millet and sorghum originated, which millions eat today. And, yet among the usual threats of climate change and wildlife habitat loss, these ecosystems face a new threat – tree planting.

It might sound like a good idea, but planting trees here would be damaging. Unlike forests, ecosystems in the tropics that are dominated by grass can be degraded not only by losing trees, but by gaining them too.




Read more:
Reforesting an area the size of the US needed to help avert climate breakdown, say researchers – are they right?


Where more trees isn’t the answer

Increasing the tree cover in savanna and grassland can mean plant and animal species which prefer open, well-lit environments are pushed out. Studies from South Africa, Australia and Brazil indicate that unique biodiversity is lost as tree cover increases.

This is because adding trees can alter how these grassy ecosystems function. More trees means fires are less likely, but regular fire removes vegetation that shades ground layer plants. Not only do herbivores like zebra and antelope that feed on grass have less to eat, but more trees may also increase their risk of being eaten as predators have more cover.

A mosaic of grassland and forest in Gabon.
Kate Parr, Author provided

More trees can also reduce the amount of water in streams and rivers. As a result of humans suppressing wildfires in the Brazilian savannas, tree cover increased and the amount of rain reaching the ground shrank. One study found that in grasslands, shrublands and cropland worldwide where forests were created, streams shrank by 52% and 13% of all streams dried up completely for at least a year.

Grassy ecosystems in the tropics provide surface water for people to drink and grazing land for their livestock, not to mention fuel, food, building materials and medicinal plants. Tree planting here could harm the livelihoods of millions.

Losing ancient grassy ecosystems to forests won’t necessarily be a net benefit to the climate either. Landscapes covered by forest tend to be darker in colour than savanna and grassland, which might mean they also absorb more heat. As drought and wildfires become more frequent, grasslands may be a more reliable carbon sink than forests.




Read more:
Exaggerating how much CO₂ can be absorbed by tree planting risks deterring crucial climate action


Redefine forests

How have we reached the point where the unique tropical savannas and grasslands of the world are viewed as suitable for wholesale “restoration” as forests?

At the root of the problem is that these grassy ecosystems are fundamentally misunderstood. The Food and Agricultural Organisation of the UN defines any area that’s half a hectare in size with more than 10% tree cover as forest. This assumes that landscapes like an African savanna are degraded because they have fewer trees and so need to be reforested. The grassy ground layer houses a unique range of species, but the assumption that forests are more important threatens grassy ecosystems across the tropics and beyond, including in Madagascar, India and Brazil.

A flowering aloe in Madagascan grassland.
Caroline Lehmann, Author provided

“Forest” should be redefined to ensure savannas and grasslands are recognised as important systems in their own right, with their own irreplaceable benefits to people and other species. It’s essential people know what degradation looks like in open, sunlit ecosystems with fewer trees, so as to restore ecosystems that are actually degraded with more sensitivity.

Calls for global tree planting programmes to cool the climate need to think carefully about the real implications for all of Earth’s ecosystems. The right trees need to be planted in the right places. Otherwise, we risk a situation where we miss the savanna for the trees, and these ancient grassy ecosystems are lost forever.The Conversation

Kate Parr, Professor of Tropical Ecology, University of Liverpool and Caroline Lehmann, Senior Lecturer in Biogeography, University of Edinburgh

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Advertisements

Greenwashing: corporate tree planting generates goodwill but may sometimes harm the planet



File 20180924 85773 b469v3.jpg?ixlib=rb 1.1
Missing the wood for the trees.
iDraw/Shutterstock

Benjamin Neimark, Lancaster University

Trees do a lot more for us than you probably think. Their roots prevent soil from eroding, their canopies provide shade and their leaves decompose into nutrients for crops, which feed livestock. Trees provide homes for a diverse range of wildlife and tree crops, such as coffee, rubber, and hardwoods, support countless livelihoods and entire economies. Trees also mark boundaries and hold immense spiritual, cultural and social value for smallholder communities around the world.

In the 1980s, charities proposed planting more trees to halt “desertification” in the Sahara Desert. This involved “afforestation” – planting trees where they had not grown for a while and “reforestation” – replacing recently lost tree cover.

Today the idea is growing strong, and an array of private companies from adult website Pornhub (yes, Pornhub) to clothing brand Ten Tree are using trees as a marketing tool.




Read more:
Pornhub has planted a few more trees, but don’t pretend it’s being responsible


Saving face or saving forests?

Businesses can offset their environmental impact by planting trees or supporting other forms of habitat restoration, so as to “pay off” the damage they cause locally. As climate change escalates, trees are in vogue for their potential to soak up the carbon dioxide we keep putting in the atmosphere.

The United Nations (UN) has even adopted a scheme for offering local communities and governments some sort of financial payout for saving trees from deforestation. This “economy of repair” has been adopted by some of the largest companies in their commitments to corporate social responsibility. One such programme is the Green Belt Movement – a Kenyan conservation NGO started by the late professor and Nobel Prize recipient Wangari Maathai.

Tree planting around the Sahara Desert has overwhelmingly relied on local efforts rather than businesses.
Niels Polderman/Shutterstock

Maathai’s original mission was to empower local people, particularly women, to overcome inequality through leading forest restoration and resisting the expanding Sahara Desert. Despite the involvement of charities and businesses, research has suggested that in programmes like these, it is farmers and local people, not companies, which make the biggest contributions to planting new trees. Since local people also inherit responsibility for them, it’s important that projects devised by outside parties are planned and executed wisely, and in the community’s interest.




Read more:
Africa’s got plans for a Great Green Wall: why the idea needs a rethink


While some may argue that tree planting is a win-win for the environment whoever does it, offsetting is just another way of corporate greenwashing. Environmental damage in one place cannot somehow be fixed by repairing habitats elsewhere, sometimes on the other side of the world.

Here are some of the ways in which indiscriminate tree planting can cause more harm than good.

Plantations are not forests

Diverse forests are often cleared for agricultural production or industrial use, and replaced by uniform stands of the same species selected because of their ability to grow fast.

Tropical forests in some cases take up to 65 years to regrow and their diversity cannot be replicated by a monoculture of reforested plots.

Ecologically illiterate

Reforestation and afforestation schemes must decide which species are appropriate to plant – native or exotic, multi-purpose or fast growing, naturally regenerating forests or managed plantations. Sometimes the wrong species are selected and Eucalyptus (Eucalyptus globulus) is one such poor choice.

Eucalyptus is usually chosen because it is fast growing and economically valuable. Yet, it is exotic to many places it is now planted and requires lots of water, which drains the water table and competes with native crops.

In Europe, replacing broad-leafed native oak trees with faster growing conifers has meant that forest cover on the continent is 10% greater than it was before the industrial revolution. However, the new trees are not as good at trapping carbon but do trap heat more efficiently, contributing to global warming. Clearly, tree planting without due caution can do more harm than good.

Trees need care – lots of it

Tree species take a long time to grow and need continual care. However, tree planting schemes usually “plant and go” –- meaning they do not put resources into managing the trees after they are placed into the ground. Young trees are particularly vulnerable to disease and competition for light and nutrients and if not cared for, will eventually die.

Newly planted tree saplings may need three to five years of frequent watering to survive.
A3pfamily/Shutterstock

Trees are political

Trees planted by states or private donors may choose sites without consulting local communities, ignoring any of their customary land rights and management regimes. This locally-owned land may be in fallow or have different economic, cultural or spiritual uses.

Blundering into planting in these places may exacerbate tensions over land tenure, spreading disinterest in tree care and stewardship. Dispossessed locals may move to existing forests and clear land for food production. Tenure rights over trees are also not always owned by whole households either, but divided between gender. Planting trees and asking questions later may sow tensions over land ownership for long after the project departs.

It’s no surprise that trees are on the green economy agenda, but this does not necessarily mean that planting them is “green” or helpful for social harmony. Allowing trees to regrow naturally is not always effective either, as trees are unlikely to survive on their own. Community involvement is therefore crucial.

This means real consultation over site and species selection, property rights over the trees, their products, and the land they grow in and who takes on the labour to keep the trees alive after they are planted. If companies are serious about planting trees then they need to care about the communities that live with them and not just their own reputations.The Conversation

Benjamin Neimark, Senior Lecturer, Lancaster Environment Centre, Lancaster University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Curious Kids: How do plastic bags harm our environment and sea life?


File 20180625 152156 1v9zr1y.jpg?ixlib=rb 1.1
Sea turtle eating a plastic bag.
from www.shutterstock.com

Britta Denise Hardesty, CSIRO and Qamar Schuyler, CSIRO

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky! You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.


My name is Sanuki and I’m 8 years old. I live in Melbourne. My question is how do plastic bags harm our environment and sea life? – Sanuki, age 8, Melbourne.


Good question, Sanuki!

Plastic bags harm marine (and land) environments in a few ways.

Turtles (and other animals) may mistake plastic bags for food. Turtles like to eat jellyfish, and we think turtles eat the plastic bags because they resemble jellyfish.

When turtles eat plastic, it can block their intestinal system (their guts). Therefore, they can no longer eat properly, which can kill them. The plastics in their tummy may also leak chemicals into the turtle. We don’t know whether this causes long term problems for the turtle, but it’s probably not good for them.




Read more:
Australian waters polluted by harmful tiny plastics


How plastic impacts the ecosystems

Plastic bags can also smother corals and other seabed communities. When plastic bags end up in our oceans, animals (including seals, dolphins and seabirds) can get tangled up in them. An animal with a plastic bag around its neck will have trouble moving through the water, catching its prey or feeding, and escaping predators.

Plastic can smother seabed and coral, impacting ecosystems.
from www.shutterstock.com

On land, plastic bags are an eyesore. They get stuck in trees, along fence lines, or as litter at our parks and beaches.

Many people don’t realise that plastic bags can also cause flooding. Previously in Ghana (in West Africa), plastic bags blocked storm water drains during a big rainstorm. This caused flooding so bad that people were killed.

Making plastic requires a lot of energy and work

Plastic bags can even be harmful before they are used. It takes a lot of resources and energy to create a plastic bag. A key ingredient is oil. As a fossil fuel, oil must be extracted from the ground. Do we want to use fossil fuel resources to make a product that is only used once (we call this a “single use plastic”)?

Many millions of barrels of oil are used to make plastic bags every year. A lot of energy is also used to make and transport plastic bags. It is better for the environment if we reduce our energy use.




Read more:
This South Pacific island of rubbish shows why we need to quit our plastic habit


The push towards plastic-free

Lately, lots of people recognise the impacts that plastic bags have, and they are working on alternatives. Many local and state governments have passed plastic bag bans here in Australia, which helps stop the use of single use plastic bags.

In fact, New South Wales is the only state in Australia where you can still get thin, single use plastic bags at the grocery store.

So, remind your parents to bring their reusable cloth bags whenever you go shopping. You just might save a turtle.


Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. They can:

* Email your question to curiouskids@theconversation.edu.au

* Tell us on Twitter


CC BY-ND

The ConversationPlease tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Britta Denise Hardesty, Principal Research Scientist, Oceans and Atmosphere Flagship, CSIRO and Qamar Schuyler, Research Scientist, Oceans and Atmospheres, CSIRO

This article was originally published on The Conversation. Read the original article.

Big game: banning trophy hunting could do more harm than good


Corey Bradshaw and Enrico Di Minin, University of Helsinki

Furious debate around the role of trophy hunting in conservation raged in 2015, after the killing of Cecil the lion in Zimbabwe, and a critically endangered black rhino in Namibia. Together, these two incidents triggered vocal appeals to ban trophy hunting throughout Africa.

While to most people (including us) this might seem like an abhorrent way to generate money, we argue in a new paper that trophy hunting, if done sustainably, can be an important tool in the conservationist’s toolbox.

Widespread condemnation

In July 2015 American dentist Walter James Palmer shot and killed a male lion called Cecil with a hunting bow and arrow, sparking a storm of outrage. Cecil was a favourite of tourists visiting Hwange National Park in Zimbabwe.

Allegations that aspects of the hunt were done illegally added considerable fuel to the flames, although Palmer was not charged by the Zimbabwean government.

Likewise in May 2015, a Texan legally shot a critically endangered black rhino in Namibia, which also generated considerable online ire. The backlash ensued even though the male rhino was considered “surplus” to Namibia’s black rhino populations, and the US$350,000 generated from the managed hunt was to be re-invested in conservation. The US government has endorsed hunting of black rhinos by allowing a limited import of rhino trophies.

These highly politicised events are but a small component of a large industry in Africa worth more than US$215 million per year, “selling” iconic animals to (mainly foreign) hunters as a means of generating otherwise scarce funds.

It’s mostly about the money

Conserving biodiversity can be expensive. Generating money has become a central preoccupation of many environmental charities, conservation-minded individuals, government agencies and scientists. Making money for conservation in Africa is even more challenging, so we argue that trophy hunting should and could fill some of that gap.

The question of whether trophy hunting is ethically justifiable is a separate issue. While animal suffering can be minimised with good practice, the moral case for or against trophy hunting is a choice we must make as a society.

Beyond the ethical or moral issues, there are still many concerns about trophy hunting that currently limit its use as a conservation tool. One of the biggest problems is that the revenue it generates often goes to the private sector rather than distributing benefits to conservation and local communities.

It can also be difficult (but not impossible) to determine just how many animals can be sustainably killed. Some forms of trophy hunting have debatable value for conservation. For instance, “canned lion hunting”, where lions are bred and raised in captivity only to be shot in specially made enclosures, provides no incentive for conserving lions in the wild.

At the same time, opposing sustainable trophy hunting could end up being worse for species conservation. While revenue from wildlife sightseeing is good, in most cases effective conservation requires much more. Without more funding creating incentives to conserve wildlife, many natural habitats will be converted to farmland, which is generally much worse for native wildlife and the entire ecosystem.

Trophy hunting can also have a smaller carbon and infrastructure footprint than ecotourism because it requires fewer paying customers for the same amount of revenue. Trophy hunting can even generate higher revenue than the most successful ecotourism enterprises.

Hunting can lead to larger wildlife populations because they are specifically managed to keep numbers higher. Larger animal populations are more resilient to extinction, and hunters have an interest in their protection. This contrasts with ecotourism where the presence of only a few individual animals is sufficient to ensure that the expectations of many paying tourists are met.

Making trophy hunting work

To address some of the concerns about trophy hunting and to enhance its contribution to biodiversity conservation and the benefit to local people, we propose twelve minimum standards:

  • Mandatory levies should be imposed on trophy hunting operators by governments. These can be invested directly into trust funds for conservation and management.

  • Trophies from areas that help conservation and respect animal welfare should be certified and labelled.

  • Populations must be analysed to ensure that killing wildlife does not cause their numbers to fall.

  • Post-hunt sales of any part of the animals should be banned to minimise illegal wildlife trade.

  • Priority should be given to trophy hunting enterprises run (or leased) by local communities.

  • Trusts should be created to share benefits with local communities and promote long-term economic sustainability.

  • Mandatory scientific sampling of animals killed, including tissue for genetic analyses and teeth for age analysis, should be enforced.

  • Mandatory five-year (or more frequent) reviews of all animals hunted and detailed conservation plans should be submitted to government legislators before permits are extended.

  • There should be full public disclosure of all data collected.

  • Independent government observers should be placed randomly and without forewarning on trophy hunts as they happen.

  • Trophies must be confiscated and permits revoked when illegal practices are discovered.

  • Backup professional shooters and trackers should be present for all hunts to minimise welfare concerns.

Can developing nations implement these strategies?

Yes, they can, but only if the funding model is transparent and includes direct support from national governments, as well as mechanisms for oversight and regulation as we have outlined. Some form of regional and international cooperation might also be necessary to minimise the chance of corruption.

Without greater oversight, better governance, and management based on scientific evidence, we fear that the furore over trophy hunting will continue – to the detriment of biodiversity, hunters and local communities. Adopting our ideas could help avoid this.

The Conversation

Corey Bradshaw, Sir Hubert Wilkins Chair of Climate Change and Enrico Di Minin, Researcher in Conservation Science, University of Helsinki

This article was originally published on The Conversation. Read the original article.

Europe: Plastic Bag Ban


The link below is to an article reporting on the possible banning of free plastic bages in Europe. The move is an attempt to stop plastic bags polluting the environment and causing harm to wildlife.

For more visit:
http://www.dailymail.co.uk/news/article-2120304/Free-plastic-bags-banned-Europe.html