The new land-use tsunami imperiling the tropics

Oil palm, oil palm, oil palm.  For years we've heard that a tidal wave of oil palm expansion is one of the biggest and fastest-growing threats to the world's rainforests.

But there's a new peril in town: rubber.  And it's also spreading like a destructive tsunami.

Spreading like wildfire

Spreading like wildfire

Two recent papers -- by Eleanor Warren-Thomas and colleagues and by Antje Ahrends and colleagues -- have underscored just how desperate the situation is becoming, especially in Southeast Asia.

As a result of escalating demand for natural rubber, plantations are increasingly gobbling up large expanses of land in Southeast Asia and the Asian mainland, as well as tropical Africa and Latin America. 

For instance, vast expanses of native forests have been cleared for rubber plantations in southern China,  which sustains many of that nation's biologically richest ecosystems

The current global production of rubber  (from Warren-Thomas  et al.  2015)

The current global production of rubber (from Warren-Thomas et al. 2015)

Warren-Thomas et al. see a rapidly worsening situation.  To meet expected demand, they estimate that from 4.3 to 8.5 million hectares of new rubber plantations -- an area up to three times the size of Belgium -- will be needed by 2024, threatening in particular significant areas of Asian forest, including many protected areas.

Expect especially rapid increases in rubber plantations in Laos, Cambodia, Vietnam, Thailand, Myanmar, Malaysia, and Indonesia, say the authors.

Ahrends and colleagues emphasize that rubber is now expanding into many areas that are ecologically marginal for rubber production.  In Southeast Asia, they estimate that 57% of the rubber plantations are currently vulnerable to droughts, erosion, frost, or wind damage.

Rubber is now spreading into marginal areas beset by high risks  (from Ahrends et al. 2015)

Rubber is now spreading into marginal areas beset by high risks (from Ahrends et al. 2015)

In 2013, for instance, typhoons in Vietnam alone destroyed over $US250 million in rubber plantations.  And future climate change could make conditions across Southeast Asia even worse for rubber, they contend.

The worst news of all is that native forests and other habitats are often being cleared for rubber production.  For example, say Ahrends et al., between 2005 and 2010, over 250,000 hectares of natural tree cover and 61,000 square kilometers of protected areas were converted to plantations in tropical and subtropical Asia.

This is scary news for the environment, for it suggests that a 'second tsunami' of forest-destroying plantations for rubber could soon follow just on the heels of the explosive expansion of oil palm.

 

Why biodiversity is declining even as protected areas increase

Why is biodiversity around the world in so much trouble, even though we keep adding new protected areas?  A new paper led by Australian researcher Ro Hill provides a compelling explanation.  Here, Ro summarizes her and her colleagues' key findings:

We’ve expanded the protected area coverage around the globe, to around 15% of the land surface -- with more than a quarter of all countries already exceeding the agreed global target of 17% by 2020.  But biodiversity loss continues apace.

Biodiversity in trouble...

Biodiversity in trouble...

Why?   Our new paper models how this paradox arises in tropical forests, from competition between governance regimes, and makes four important points:

1. The forces that drive forest protection do not necessarily oppose those that drive forest clearance for development. 

The diagram above says it all: we can keep expanding the developed area of the planet AND expanding protected areas as long as there are still some remaining forested habitats.
 
The power of the “develop” and “protect” governance regimes determines the strength of the forces that move the boundaries between areas under protection, areas of remaining forest habitat, and areas under development.

The leaders of the G20 nations recently gave a huge boost to the power of development regimes by promising to invest 60-70 trillion U.S. dollars on new infrastructure projects by the year 2030.  There is no such investment for conservation -- nothing even close!

2.   The power of the “protect” governance regime can actually be lowered as protected areas increase.
 
People may believe that when new protected areas are created, there are more natural areas –- whereas the reality is that every day there are less.  This lowers public concerns about risks from biodiversity loss, decreasing pressure on politicians and weakening the power of the “protect” governance regime.
 
3.  Prioritizing protected area placement by proximity to active agricultural frontiers would make them more effective.

Targets should include both the desired Area under protection AND the absolute limits on Area under development through habitat conversion.

4.  Strengthening the forces that maintain and restore habitat (and oppose its development) is vital to halt biodiversity loss.

This means we must generally favor land-sharing as a conservation strategy rather than land-sparing.  The governance forces that drive land sparing don’t necessarily oppose the governance forces that drive forest clearance for development, so you still get net loss.
 
Hence, strengthening the relative power of land-sharing governance regimes (i.e. those that maintain traditional, sustainable land use, alternative sustainable land use, or restore degraded habitat) is likely, we argue, to have a greater long-term benefit for biodiversity conservation.

Unraveling how governance and power affect biodiversity conservation is a new frontier in conservation science -– but this paper makes an important start and shows where we need to focus our attention.

 

Perils growing for Earth's biodiversity hotspots

Biodiversity hotspots are Earth's most biologically important real estate.  An important new study -- which you can download free here -- sees dark clouds on the horizon for many these crucial ecosystems.

Where the rare things live...

Where the rare things live...

There are 35 biodiversity hotspots across the planet.  They encompass a wide range of different ecosystems but they all have two key features:

First, they're jam-packed with species, especially those that don't occur anywhere else on Earth.  These are known as "locally endemic species" and they're notoriously vulnerable, because they live in just one small area.  For instance, the island of Madagascar has lots of species, such as lemurs, that are completely unique to the island.

Second, hotspots, by definition, have been nuked by land-use change: at least 70% of the original vegetation has disappeared.

The new paper, led by geographer Sean Sloan and including ALERT director Bill Laurance, used a rigorous satellite analysis to estimate how much of the original vegetation survives in an intact condition in each hotspot. 

Unfortunately, most hotspots have much less intact vegetation than previously estimated.  Half now have less than a tenth of their original vegetation -- at which points things start to look seriously dodgy for biodiversity, in part because the original habitat gets severely fragmented and reduced.

An interesting finding is that the hotspots that were formerly in the best shape, in terms of having more of their original vegetation, suffered the worst.  Drier habitats, such as dry forests, open woodlands, and grasslands, fared badly, largely because of expanding agriculture.

These findings highlight an important reality.  For biodiversity, the Earth is far from homogenous, with certain crucial regions overflowing with rare species.  Conserving the last vestiges of these endangered ecosystems is simply vital if we're going to ward off a catastrophic mass-extinction event.

 

Nature worth "$145 trillion per year" to humanity

Nature isn't priceless.  In fact, economists can give it quite a specific price: about $145 trillion per year, if the net value of all ecosystem services is tallied up.

What's a nice sunset worth?   (photo by William Laurance)

What's a nice sunset worth?  (photo by William Laurance)

Yes, that's 145 trillion dollars -- as in 145 with 12 zeros behind it. 

This new finding--which you can download free here--comes from a major analysis of global ecosystem services led by economist Robert Costanza of Australian National University.

Ecosystem services include a wide array of things such as carbon storage, crop pollination, fisheries, recreational opportunities, flood mitigation, and the provisioning of clean water.

While the new result underscores the astonishingly important role that nature plays in human welfare, there's also a kicker: the annual value of ecosystem services has declined by up to $20 trillion between 2007 and 2011, according to Costanza and colleagues, principally because of habitat destruction and other land-use changes.  And that erosion in value is ongoing.

Putting a price on nature is tricky and inevitably some people will object to the idea.  For instance, how can you place a dollar value on having clean air to breathe, or a wilderness to hike in, or hearing a rare bird sing?

But doing so underscores an important point: Even in the most utilitarian sense, nature has incredible value to humanity, and that value is being eroded.  Like any valuable resource, we're nothing short of foolish if we merely squander it.

 

Species disappearing "1000 times faster than normal"

Want to know one of the most hotly debated questions in environmental science?  It's this: How fast are species disappearing today?  A new paper in the leading journal Science suggests the answer is -- very fast indeed.

Undiscovered species... this Amazonian jay doesn't even have a scientific name yet (photo by Mario Cohn-Haft)

Undiscovered species... this Amazonian jay doesn't even have a scientific name yet (photo by Mario Cohn-Haft)

The paper, led by ALERT member and Duke University Professor Stuart Pimm with a team of eminent coauthors, makes several key arguments:

- Species extinctions today are occurring roughly 1000 times faster than the 'background' (or natural) rate that prevailed before humans appeared on Earth

- We know where the most imperiled species are located, with particularly big concentrations in the tropical Asia-Pacific region, especially in places like the Philippines, Borneo, and Sumatra

-Other regions with lots of extinction-prone species include the Andes mountains, West Africa, Madagascar, and other scattered pockets of the world

- Millions of species have not yet been discovered (scientifically described or studied) by scientists; for example, huge numbers of plant, insect, fungi, and nematode species are undiscovered, among many others

- Many of the undiscovered species are imperiled because they have small geographic ranges and occur in vulnerable parts of the world -- known as 'biodiversity hotspots' -- that have already lost much of their original habitat

- Protecting the surviving habitats in the biodiversity hotspots is crucial if we are to stave off a dramatic collapse of biodiversity on Earth

For those who care about biodiversity, this paper (which you can download free at the link above) is an authoritative and highly readable summary of what we know, think, and suspect about the future of life on Earth.