Some good conservation news: India’s tiger numbers are going up



Spotting tigers in the wild is a difficult task.
Author provided

Matt Hayward, University of Newcastle and Joseph K. Bump, University of Minnesota

Indian tiger numbers are up, according to one of the most detailed wildlife surveys ever conducted. Tiger populations have risen by 6%, to roughly 3,000 animals.

The massive survey may set a new world standard in counting large carnivores. The encouraging results validate India’s impressive investments in tiger conservation.




Read more:
Tigers confirmed as six subspecies, and that is a big deal for conservation


A mammoth effort

Large, solitary predators hate being seen. They owe their entire existence to being able to avoid detection by prey and sneak close before attacking.

Hence, when we want to count tigers, the tigers don’t help. But accurate population numbers are fundamental to good conservation. Every four years since 2006, the Indian government conducts a national census of tigers and other wildlife.

The efforts the project team undertakes to derive the tiger population estimate are nothing short of phenomenal: 44,000 field staff conducted almost 318,000 habitat surveys across 20 tiger-occupied states of India. Some 381,400 km² was checked for tigers and their prey.

(There is an application in with the Guinness Book of World Records to see if this is the largest wildlife survey ever conducted anywhere in the world.)

The team placed paired camera traps at 26,760 locations across 139 study sites and these collected almost 35 million photos (including 76,523 tiger and 51,337 leopard photos). These camera traps covered 86% of the entire tiger distribution in India. Where it was too dangerous to work in the field (14% of the tigers’ distribution) because of political conflict, robust models estimated population numbers.

Millions of photos were analysed to create an accurate count of India’s tiger population.
Author provided

Count the tigers

Collecting this volume of data would be an utter waste of time if it were poorly analysed. The teams took advice from some of the world’s foremost experts to sort the photos: pattern matching experts who could identify whether a photo of a tiger taken in the monsoon matched that of a tiger taken in the dry season while walking at a different angle, machine learning experts to speed up species identification, and spatial analysis experts to estimate the populations of tigers and their prey.

The research team took this advice and coupled it with their own knowledge of tiger ecology to develop a census that is unique among large carnivore studies.

We were fortunate enough to be among the non-Indian scientists invited to review this process. Peer review is a crucial part of any scientific endeavour, and especially important as early Indian tiger surveys were notoriously unreliable.

Actual numbers

So how did they do? A total of 2,461 individual tigers older than one year of age were photo-captured. The overall tiger population in India was estimated at 2,967 individuals (with an error range of roughly 12%).

Out of this, 83.4% were estimated from camera-trap photos, and the rest estimated from robust modelling. Tiger numbers have increased by 6% per year, continuing the rate of increase from the 2014 census. This is a wonderful success for Indian conservation efforts.

However not all is rosy. There has been a 20% decline in areas occupied by tigers in 2014 to today, although tigers have moved into some new areas (some 8% of their Indian range is new). The coordinators of the tiger survey – Yadvendradev Jhala and Qamar Qureshi – conclude that while established and secure tiger populations in some parts of India have increased, small, isolated populations and those along corridors between established populations have gone extinct.

This highlights the need for conservation efforts to focus on improving connectivity between isolated populations, while incentivising the relocation of people out of core tiger areas, reducing poaching and improving habitat to increase prey resources.

This will be no easy task with India’s burgeoning population, but investment from private sector tourist corporations in land acquisition along corridors and the creation of community conservancies could supplement government funding for expanding protected corridors.




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The success of India’s census has led the governments of Nepal and Bangladesh to employ the same project team to help estimate their own tiger populations. These methods can – and should – be employed for other iconic, charismatic species that can be individually identified, such as jaguars in South and Central America; leopards, cheetahs, and hyenas in Africa, and possibly even quolls in Australia.


This article was co-authored by Chris Carbone, Senior Research Fellow at the Zoological Society of London.The Conversation

Matt Hayward, Associate professor, University of Newcastle and Joseph K. Bump, Associate Professor, Gordon W. Gullion Endowed Chair in Forest Wildlife Research and Education, University of Minnesota

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

NSW’s water plan is ‘not working’ but we can save the Barwon-Darling


Barry Hart, Monash University

The plan to manage water in the Barwon-Darling is not working, according to a draft review released last week.

The New South Wales Natural Resources Commission, which released the draft report, found the Barwon-Darling is an “ecosystem in crisis”. The report provides a robust blueprint for a more sustainable water-sharing plan.

The review confirms criticism the existing plan gives too much water to irrigators and has added to pressures on the entire Murray-Darling ecosystem.




Read more:
5 ways the government can clean up the Murray-Darling Basin Plan


What the plan covers

The draft review examines the 2012 Water Sharing Plan for the Barwon-Darling, which covers 1,600km of the river from Mungindi to Wilcannia. The river here flows south-west through a relatively narrow floodplain with a tightly meandering channel and a highly variable flow pattern.

The river is unregulated and depends heavily on upstream rivers for its water (for example, Condamine–Balonne, Border rivers, Gwydir and Namoi).

January’s massive fish kills around Menindee are only the most recent example of the pressures on the river’s ecosystems. Alongside the fish deaths, research has shown that other aquatic species in the system, such as river mussels, have suffered losses that will take many decades to recover.




Read more:
We wrote the report for the minister on fish deaths in the lower Darling – here’s why it could happen again


Communities that live along the river told the commission people can no longer fish, swim or drink the river water. Graziers struggle to provide water for their stock because the river dries up more often.

Indigenous communities are particularly affected because without water their strong connection to the river – the Barka – is being damaged. A Barkandji elder told the commission:

The river is everything. It’s my life, my culture. You take the water away from us, we’ve got nothing.

Bad priorities

While the review found drought, upstream water extraction in NSW and Queensland and climate change have all contributed to these problems, the greatest effect comes from inappropriate water-sharing rules, particularly when water levels are low.

The law underpinning river management in NSW prioritises protecting the environment and basic landholder rights (including native title) over irrigation. However, the commission found the current plan does not achieve this.

In fact, the plan has been highly controversial since it was enacted in 2012. This in large parts arose because major changes were made between the draft plan circulated in 2011 and the actual plan gazetted in 2012. The commission documents 16 such changes in the review and rates six as substantial.

The NSW government did not publicly explain the reason for such significant alteration in 2012, but there has been much speculation powerful vested interests influenced the government to provide more water for irrigation.

The most important effect of these changes was letting irrigators take water even when the river is very low. The review concludes:

These provisions benefit the economic interests of a few upstream users over the ecological and social needs of the many.




Read more:
The Darling River is simply not supposed to dry out, even in drought


What to do?

The review recommends the NSW government urgently change water-sharing rules so these better comply with the legal requirements to protect the environment and other water users, restore community trust and make the river more resilient to future shocks.

Key priorities for the NSW government are:

  • redesigning the water-sharing rules so environmental protection and basic landholder rights cannot be harmed by lesser priorities such as irrigation

  • introduce new flow targets to more effectively protect critical ecosystems and enhance river health

  • change rules relating to water extractions by A Class licence holders during critical low-flow periods, particularly those relating to commence-to-pump, cease-to-pump, and the size of pumps.

  • introduce and enforce more effective metering and monitoring

  • develop strategies and rules that address the inevitable impacts of climate change

  • develop and implement more integrated management of water resources in the northern Murray-Darling Basin.

The commission did note there have been positive changes to the NSW government’s approach to water policy and management since the ABC 4 Corners report Pumped in 2017 and the subsequent Ken Matthews report.

However, the Murray-Darling Basin Plan required NSW to complete a new water resource plan for the Barwon-Darling River by June 2019. The state missed this deadline. The NSW water minister has requested an extension to December 31 2019. A recent assessment by the Murray-Darling Basin Authority suggests NSW is still some way from completing this water resource plan.




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Drought and climate change are driving high water prices in the Murray-Darling Basin


While NSW delays, the Barwon-Darling river system and its communities suffer. The NSW government now has an excellent blueprint for a new plan. It must urgently implement the review’s 29 recommendations and complete a new plan for the Barwon-Darling before the end of 2019.The Conversation

Barry Hart, Emeritus Professor Water Science, Monash University

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

There’s a simple way to drought-proof a town – build more water storage



Inland towns need far more water storage.
Flickr/Mertie, CC BY-SA

Michael Roderick, Australian National University

The federal parliament has voted to funnel A$200 million to drought-stricken areas. What exactly this money will be spent on is still under consideration, but the majority will go to rural, inland communities.

But once there, what can the money usefully be spent on? Especially if there’s been a permanent decline in rainfall, as seen in Perth. How can we help inland communities?




Read more:
Recent Australian droughts may be the worst in 800 years


Let’s look at the small inland town of Guyra, NSW, which is close to running dry. Unlike our coastal cities, Guyra cannot simply build a billion-dollar desalination plant to supply its water. Towns like Guyra must look elsewhere for its solutions.

Running dry isn’t just about rainfall

“Running dry” means there is no water when the tap is turned on. It seems to make sense to blame the drought for Guyra’s lack of water. But the available water supply is not only determined by rainfall. It also depends on amount of water flowing into water storage (called streamflow), and the capacity and security of that storage.

While Perth has had a distinct downturn in its rainfall since the 1970s and has built desalination plants to respond to this challenge, no such downturn is evident at Guyra. Indeed, to date, the driest consecutive two years on record for Guyra were 100 years ago (1918 and 1919).

Long-term rainfall records for Perth (left) and Guyra (right). Dashed red line shows the trend and the full yellow line shows 600 mm annual rainfall.
Bureau of Meteorology

Despite the differences, there are some similarities between Perth and Guyra. As a rule of thumb, in Australia, significant streamflow into water storages does not occur until annual rainfall reaches around 600mm. This occurs as streamflow is generally supplied from “wet patches” when water can no longer soak into the soil. Thus, if annual rainfall is around 600mm or below, we generally anticipate very little streamflow.

While Guyra has seen some rain in 2019, it is not enough to prompt this crucial flow of water into the local water storage. The same is true for Perth, with annual rainfall in the past few decades now hovering close to the 600mm threshold.

Importantly, rainfall and streamflow do not have a linear relationship. Annual rainfall in Perth has declined by around 20%, but Perth’s streamflow has fallen by more than 90%.

With little streamflow filling its dams, Perth had little choice but to find other ways of increasing its water supply. They built desalination plants to make up the difference.

Let’s return to Guyra in NSW and the current drought. The rainfall records do not indicate there is a long-term downward trend in rainfall. But even without a rainfall trend, there are still dry years when there is little streamflow. Indeed, in Guyra, the rainfall record shows that, on average, the rainfall will be 600mm or less roughly one year out of every ten years.

Build more storage

So how do the residents of Guyra ensure a reliable water supply, given that they cannot build themselves a desalination plant?

Well, in this case, you can simply get water from somewhere else if it is available. A pipeline is currently under construction to supply Guyra from the nearby Malpas Dam, and is expected to be in operation very soon.

But that’s not always an option. A made-in-Guyra water solution means one thing: expanding storage capacity.

Guyra can generally store around 8 months of their normal water demand (although of course demand varies with the seasons, droughts, water restrictions and price per litre).

To give a point of comparison, Sydney can store up to five years of its normal water demand, and has a desalination plant besides. Despite these advantages, Sydney residents are now under stage one water restrictions which happens when its storages are only 50% full. Yet, even when Sydney’s glass is only half-full, that city still has at least another two years of water left to meet the expected water demand even without using desalination.

By comparison, when water storages in Guyra are 50% full, they have less than six months normal water supply.

It is astonishingly difficult to find accurate data on small-town water supplies but in my experience Guyra is not unique among rural towns. There is a big divide between the water security of those living in Australia’s big cities compared to smaller inland towns. Many rural communities simply do not have sufficient water storage to withstand multi-year droughts, and in some cases, cannot even withstand one year of drought.




Read more:
Droughts, extreme weather and empowered consumers mean tough choices for farmers


Nature, drought and climate change cannot be blamed for all of our water problems. In rural inland towns, inadequate planning and funding for household water can sometimes be the real culprit. Whether Australians live in rural communities or big cities, they should be treated fairly in terms of both the availability and the quality of the water they use.The Conversation

Michael Roderick, Professor, Research School of Earth Sciences and Chief Investigator in the ARC Centre of Excellence for Climate Extremes, Australian National University

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

The Albany pitcher plant will straight up eat you (if you’re an ant)



FEED me, Seymour!
Adam Cross, Author provided

Adam Cross, Curtin University

Sign up to the Beating Around the Bush newsletter here, and suggest a plant we should cover at batb@theconversation.edu.au.


On a warm evening in early 1802, Robert Brown sat aboard the HMS Investigator describing several plant specimens collected that day. Brown was the botanist on Captain Matthew Flinders’ expedition, and they had been anchored in King George Sound for nearly a month documenting the remarkable flora of the area.

He keenly awaited the return of their gardener, Peter Good, who had left earlier in search of a curious “pitcher plant” discovered the previous morning by botanical artist Ferdinand Bauer and landscape artist William Westall.




Read more:
Death traps: how carnivorous plants catch their prey


Unbeknownst to him, in minutes he would be gazing upon a uniquely wondrous plant: Cephalotus follicularis, the Albany pitcher plant.

Named after the southwestern Australian port city around which it occurs, the Albany pitcher plant stands out as an oddity even by the standards of carnivorous plants. The species is instantly recognisable, as it produces distinctive insect-trapping pitcher leaves that sit on the ground almost expectantly waiting for prey.



The Conversation

The toothed mouth and overarching lid of these pitchers look superficially similar to those of the tropical pitcher plants (Nepenthes) and North American pitcher plants (Sarracenia). However, these plants are not related; this similarity is a remarkable example of convergent evolution. The Albany pitcher plant is unique.

C. follicularis is the only species in the genus Cephalotus, which is the only genus within the family Cephalotaceae. Its nearest living relatives are rainforest trees from tropical South America, from which it is separated by some 50 million years. Indeed, it is the only carnivorous plant among the 70,000 species, a quarter of all flowering plants, that make up one of the largest evolutionary plant groups, the rosid clade.




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When Thailand and Australia were closer neighbours, tectonically speaking


The Albany pitcher plant is more closely related to cabbages, roses and pumpkins than it is to other pitcher plants.

The Albany pitcher plant only grows in a very small area of Western Australia, and is thought to be an ancient Gondwanan relict from a period when this region was almost tropical. It grows in nutrient-poor soils of coastal swamps and lowlands, where it survives by luring insects into its traps to be digested in a pool of enzymes at the base of each pitcher. Each pitcher bears a lid to prevent rain from diluting the pool of enzymes, with translucent windows to disorient trapped prey and prevent escape.

Interestingly, one species of insect not only survives inside the fluid of the pitchers, but relies on it for survival. The wingless stilt fly Badisis ambulans lays its eggs in the pitchers, and the larvae develop in the pool of pitcher fluid, feeding on captured prey.

The wingless stilt fly lives inside the Albany pitcher plant.
Tony D/Wikimedia, CC BY

These stilt flies live only in the dense vegetation of the swamps inhabited by the Albany pitcher plant. They look more like an ant than a fly, which is probably a deliberate mimicry of the ant Iridomyrmex conifer, the primary prey of the pitcher plant. It is likely that these three species – plant, fly and ant – have co-evolved together over millions of years.

The Albany pitcher plant was probably widespread in the southwest corner of WA before European settlement, and almost 150 populations have been recorded throughout this region. However, the species has declined dramatically over the past century as extensive land has been cleared throughout the southwest for agriculture and urban development.

The Albany pitcher plant now occurs only as small, isolated populations in remnant habitat patches. It is thought that less than 3,000 hectares of habitat suitable for the species now remains in the greater Albany region. Recent survey efforts suggest that fewer than 20 populations of the Albany pitcher plant still exist, and fewer than 5,000 plants remain.

Despite the perilous state of the Albany pitcher plant, it still has no formal conservation status. Indeed, swamps containing the species have been bulldozed for housing development in the past 12 months. But habitat loss and changes to bushfire frequency and water flow are not the only threats to this amazing species. Current projections of a drying climate in the southwest of Western Australia may see the species pushed towards extinction in the coming decades.

Incredibly, the Albany pitcher plant is also at risk from poaching. The species is prized for its horticultural novelty, and unscrupulous individuals dig up plants from the wild either to grow or sell. At one accessible location where the species was known to grow in abundance, every single plant within reach has been removed. At other sites, entire populations have been dug up.




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The waterwheel plant is a carnivorous, underwater snap-trap


Without improved conservation measures, and tough penalties for removing this incredible species from its natural habitat, the Albany pitcher plant and its complex web of insect relationships face a potentially dire future.


Sign up to Beating Around the Bush, a series that profiles native plants: part gardening column, part dispatches from country, entirely Australian.The Conversation

Adam Cross, Research Fellow, Curtin University

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

Our cities need more trees, but some commonly planted ones won’t survive climate change


Australian cities could lose some of their most common trees to climate change.
Jamen Percy/Shutterstock

Alessandro Ossola, Macquarie University; Hugh Munro Burley, Macquarie University; Leigh Staas, Macquarie University; Linda Beaumont, Macquarie University; Michelle Leishman, Macquarie University, and Rachael Gallagher, Macquarie University

We need trees in our lives. This past summer, Adelaide experienced the hottest temperature ever recorded in an Australian state capital, hitting 46.6 degrees on January 24. Trees beautify otherwise grey cities and cool our suburbs during heatwaves. But different species have different levels of tolerance of heat, lack of water and other threats posed by climate change.

In a newly published study, we investigated likely climate change impacts on 176 of the most common tree species planted across Australian cities. Our analysis showed more than 70% of these species will experience harsher climatic conditions across Australian cities by 2070. Some of the most commonly planted trees are unlikely to survive these conditions.

The golden wattle might struggle in our northern cities if they get hotter and drier.
Dryas/Wikimedia Commons, CC BY-SA

So which tree species are best suited to particular places? Which species are more likely to thrive, rather than just survive, under a changing climate? Which of our beloved tree species won’t make it?

Tree species growing in warmer cities are more likely to be affected than those in cooler cities. Some species, such as the golden wattle (Acacia longifolia) or the prickly paperbark (Melaleuca styphelioides), might not make it in northern cities, unless we invest precious resources – such as water – to maintain these civic assets. Other species, such as the native frangipani (Hymenosporum flavum) or the tuckeroo (Cupaniopsis anacardioides), will likely become more suitable for planting in southern cities.




Read more:
We’re investing heavily in urban greening, so how are our cities doing?


Why do cities need trees?

Trees are wonderfully effective at improving the microclimate of our cities, which makes tree plantings an effective and efficient way to adapt to climate change. The leaves of trees absorb and dissipate much of the sun’s radiation.

Trees cool air and land by several degrees compared to areas of concrete and asphalt. Swipe the heat map below to see how effectively trees cool down our cities. (Red indicates hotter areas, blue cooler areas.)

Swipe the map to see how much trees cool urban areas. Red indicates hotter areas, blue cooler areas. This temperature map was collected during a heatwave in Adelaide, South Australia, on February 9 2017 by AdaptWest over the cities of West Torrens, Charles Sturt and Port Adelaide-Enfield.
Used with permission of AdaptWest Adelaide (https://www.adaptwest.com.au/mapping/heat-maps)



Read more:
Building cool cities for a hot future


Governments recognise the importance of trees and have developed vital initiatives, such as the national 20 Million Trees program and the 5 Million Trees program in New South Wales. These are important first steps to increase urban tree cover across Australia. But the question arises: are we planting the right tree species?

What does the science say?

Australian cities are blessed with a higher diversity of tree species compared to other cities globally. However, the 30 most commonly planted species make up more than half of Australia’s urban forests.

This poses a great risk for our cities. If we were to lose one or two of these common species, the impact on our urban tree cover would be immense. Consequently, our best insurance is to increase the diversity of our trees.

Species composition of Australia’s urban forests across 60 local government areas. The size of each word is proportional to the number of tree stems recorded for each species.
Alessandro Ossola

Our quest to find climate-ready tree species is only just beginning. Supported by Hort Innovation Australia, the NSW Department of Planning, Industry and Environment, and the Commonwealth government, our team embarked on a project called Which Plant Where in conjunction with researchers at Western Sydney University. Our mission is to find the best plant species for urban landscapes that will be resilient to climate change.

We work with the nursery industry to provide evidence on species’ resilience to extreme heat and drought by testing plants to their limits in research glasshouses. Our work with plant growers and nurseries will inform them on how to adapt their business, by identifying the new challenges posed by climate change, as well as selecting highly diverse palettes of climate-ready species. We advise landscape architects, designers and urban planners about not only the best planting choices, but also how to increase the biodiversity of our cities.




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For green cities to become mainstream, we need to learn from local success stories and scale up


You can help!

We are committed to do more science in coming years, but you can start making a difference today. Australia’s National Tree Day will be celebrated again this year on Sunday, July 28. It’s a great opportunity to teach our families, communities and businesses about the importance of tree planting and environmental stewardship as key elements of adapting to climate change.

An old Chinese adage says:

The best time to plant a tree was 20 years ago. The second best time is now.

This weekend is your time. The game is simple – head to your closest plant nursery. Ask your local grower about which tree species are suitable for the local growing conditions and pick one you like. Then, plant a tree in your yard, or join one of the many planting events across Australia.

Teach your kids, family and friends about the difference they can start making today – for their future and our common good – one tree at a time. The Conversation

A plant nursery growing a diverse range of tree species for the upcoming planting season.
Alessandro Ossola

Alessandro Ossola, Research Coordinator Centre for Smart Green Cities, Macquarie University; Hugh Munro Burley, Spatial analyst, Macquarie University; Leigh Staas, Associate Director for Engagement & Research Partnerships | Smart Green Cities, Macquarie University; Linda Beaumont, Senior Lecturer, Macquarie University; Michelle Leishman, Distinguished Professor, Head of Department, Macquarie University, and Rachael Gallagher, , Macquarie University

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

Extreme weather caused by climate change has damaged 45% of Australia’s coastal habitat



Bleached staghorn coral on the Great Barrier Reef. Many species are dependent on corals for food and shelter.
Damian Thomson, Author provided

Russ Babcock, CSIRO; Anthony Richardson, The University of Queensland; Beth Fulton, CSIRO; Eva Plaganyi, CSIRO, and Rodrigo Bustamante, CSIRO

If you think climate change is only gradually affecting our natural systems, think again.

Our research, published yesterday in Frontiers in Marine Science, looked at the large-scale impacts of a series of extreme climate events on coastal marine habitats around Australia.

We found more than 45% of the coastline was already affected by extreme weather events caused by climate change. What’s more, these ecosystems are struggling to recover as extreme events are expected to get worse.




Read more:
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There is growing scientific evidence that heatwaves, floods, droughts and cyclones are increasing in frequency and intensity, and that this is caused by climate change.

Life on the coastline

Corals, seagrass, mangroves and kelp are some of the key habitat-forming species of our coastline, as they all support a host of marine invertebrates, fish, sea turtles and marine mammals.

Our team decided to look at the cumulative impacts of recently reported extreme climate events on marine habitats around Australia. We reviewed the period between 2011 and 2017 and found these events have had devastating impacts on key marine habitats.

Healthy kelp (left) in Western Australia is an important part of the food chain but it is vulnerable to even small changes in temperature and particularly slow to recover from disturbances such as the marine heatwave of 2011. Even small patches or gaps (right) where kelp has died can take many years to recover.
Russ Babcock, Author provided

These include kelp and mangrove forests, seagrass meadows, and coral reefs, some of which have not yet recovered, and may never do so. These findings paint a bleak picture, underscoring the need for urgent action.

During this period, which spanned both El Niño and La Niña conditions, scientists around Australia reported the following events:

2011: The most extreme marine heatwave ever occurred off the west coast of Australia. Temperatures were as much as 2-4℃ above average for extended periods and there was coral bleaching along more than 1,000km of coast and loss of kelp forest along hundreds of kilometres.

Seagrasses in Shark Bay and along the entire east coast of Queensland were also severely affected by extreme flooding and cyclones. The loss of seagrasses in Queensland may have led to a spike in deaths of turtles and dugongs.

2013: Extensive coral bleaching took place along more than 300km of the Pilbara coast of northwestern Australia.

2016: The most extreme coral bleaching ever recorded on the Great Barrier Reef affected more than 1,000km of the northern Great Barrier Reef. Mangrove forests across northern Australia were killed by a combination of drought, heat and abnormally low sea levels along the coast of the Gulf of Carpentaria across the Northern Territory and into Western Australia.

2017: An unprecedented second consecutive summer of coral bleaching on the Great Barrier Reef affects northern Great Barrier Reef again, as well as parts of the reef further to the south.

Heritage areas affected

Many of the impacted areas are globally significant for their size and biodiversity, and because until now they have been relatively undisturbed by climate change. Some of the areas affected are also World Heritage Areas (Great Barrier Reef, Shark Bay, Ningaloo Coast).

Seagrass meadows in Shark Bay are among the world’s most lush and extensive and help lock large amounts of carbon into sediments. The left image shows healthy seagrass but the right image shows damage from extreme climate events in 2011.
Mat Vanderklift, Author provided

The habitats affected are “foundational”: they provide food and shelter to a huge range of species. Many of the animals affected – such as large fish and turtles – support commercial industries such as tourism and fishing, as well as being culturally important to Australians.

Recovery across these impacted habitats has begun, but it’s likely some areas will never return to their previous condition.

We have used ecosystem models to evaluate the likely long-term outcomes from extreme climate events predicted to become more frequent and more intense.

This work suggests that even in places where recovery starts, the average time for full recovery may be around 15 years. Large slow-growing species such as sharks and dugongs could take even longer, up to 60 years.

But extreme climate events are predicted to occur less than 15 years apart. This will result in a step-by-step decline in the condition of these ecosystems, as it leaves too little time between events for full recovery.

This already appears to be happening with the corals of the Great Barrier Reef.

Gradual decline as things get warmer

Damage from extreme climate events occurs on top of more gradual changes driven by increases in average temperature, such as loss of kelp forests on the southeast coasts of Australia due to the spread of sea urchins and tropical grazing fish species.

Ultimately, we need to slow down and stop the heating of our planet due to the release of greenhouse gases. But even with immediate and effective emissions reduction, the planet will remain warmer, and extreme climatic events more prevalent, for decades to come.

Recovery might still be possible, but we need to know more about recovery rates and what factors promote recovery. This information will allow us to give the ecosystems a helping hand through active restoration and rehabilitation efforts.




Read more:
More than 28,000 species are officially threatened, with more likely to come


We will need new ways to help ecosystems function and to deliver the services that we all depend on. This will likely include decreasing (or ideally, stopping) direct human impacts, and actively assisting recovery and restoring damaged ecosystems.

Several such programs are active around Australia and internationally, attempting to boost the ability of corals, seagrass, mangroves and kelp to recover.

But they will need to be massively scaled up to be effective in the context of the large scale disturbances seen in this decade.The Conversation

Mangroves at the Flinders River near Karumba in the Gulf of Carpentaria. The healthy mangrove forest (left) is near the river while the dead mangroves (right) are at higher levels where they were much more stressed by conditions in 2016. Some small surviving mangroves are seen beginning to recover by 2017.
Robert Kenyon, Author provided

Russ Babcock, Senior Principal Research Scientist, CSIRO; Anthony Richardson, Professor, The University of Queensland; Beth Fulton, CSIRO Research Group Leader Ecosystem Modelling and Risk Assessment, CSIRO; Eva Plaganyi, Senior Principal Research Scientist, CSIRO, and Rodrigo Bustamante, Research Group Leader , CSIRO

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

Increasing tree cover may be like a ‘superfood’ for community mental health



Imagine Hyde Park in Sydney without its tree cover … the impact on this space and the many people who spend time in it would be profound.
EA Given/Shutterstock

Thomas Astell-Burt, University of Wollongong and Xiaoqi Feng, University of Wollongong

Increasing tree canopy and green cover across Greater Sydney and increasing the proportion of homes in urban areas within 10 minutes’ walk of quality green, open and public space are among the New South Wales premier’s new priorities. Cities around Australia have similar goals. In our latest study, we asked if more of any green space will do? Or does the type of green space matter for our mental health?

Our results suggest the type of green space does matter. Adults with 30% or more of their neighbourhood covered in some form of tree canopy had 31% lower odds of developing psychological distress. The same amount of tree cover was linked to 33% lower odds of developing fair to poor general health.

We also found poorer mental and general health among adults in areas with higher percentages of bare grass nearby, but there’s likely more to that than meets the eye.




Read more:
Green for wellbeing – science tells us how to design urban spaces that heal us


Treed neighbourhoods have a natural appeal to people.
Tim Gouw/Unsplash

How did we do the research?

Our research involved tracking changes in health over an average of about six years, for around 46,000 adults aged 45 years or older, living in Sydney, Newcastle or Wollongong. We examined health in relation to different types of green space available within a 1.6 kilometre (1 mile) walk from home.

Our method helped to guard against competing explanations for our results, such as differences in income, education, relationship status, sex, and age. We also restricted the sample to adults who did not move home, because it is plausible that people who are already healthier (for instance because they are more physically active) move into areas with more green space.

So is the answer simply more trees and less grass? Not exactly. Let’s get into the weeds.




Read more:
Green space – how much is enough, and what’s the best way to deliver it?


Trees make it cool to walk

Imagine you’re walking down a typical street on a summer’s day in the middle of an Australian city. It’s full of right angles, grey or dark hard surfaces, glass structures, and innumerable advertisements competing for your attention. Then you turn a corner and your gaze is drawn upwards to a majestic tree canopy exploding with a vivid array of greens for as far as you can see.

A tree-lined street like Swanston Street in Melbourne is a more walkable street.
kittis/Shutterstock

Let’s get the obvious out of the way. Walking down this green street, you may instantly feel some relief from the summer heat.

Studies are linking high temperatures with heat exhaustion and mental health impacts. Research has suggested trees, rather than other forms of green space, may be best at reducing temperatures in cities. It may also simply be more comfortable to walk outside in cooler temperatures – not to mention going for a run or bike ride, both of which are good for mental health.




Read more:
Our cities need more trees, but some commonly planted ones won’t survive climate change


Feeling restored and alert

But as the minutes of walking beneath this natural umbrella of lush foliage accumulate, other things are happening too. The vibrant colours, natural shapes and textures, fresh aromas, and rustling of leaves in the breeze all provide you with effortless distraction and relief from whatever it was you might have been thinking about, or even stressing over.

Trees can provide a soothing sensory distraction from our troubles.
Jake Ingle/Unsplash

Studies back this up. Walks through green space have been shown to reduce blood pressure, improve mental acuity, boost memory recall, and reduce feelings of anxiety. The Japanese have a name for this type of experience: shinrin-yoku.

Friends, old and new

You walk past groups of people on the footpath taking time to catch up over coffee in the shade. Some research has found that tree cover, rather than green space more generally, is a predictor of social capital. Social capital, according to Robert Putnam, refers to the “social networks and the associated norms of reciprocity and trustworthiness” that may have important influences on our life chances and health.

Dogs and trees both contribute to building healthy social relations.
Liubov Ilchuk/Unsplash

You walk further and a chorus of birdsong soars through the neighbourhood noise. Trees provide shelter and food for a variety of animals. Research suggests tree canopy tends to be more biodiverse than low-lying vegetation.

Increased biodiversity may support better mental health by enhancing the restorative experience and also via the immunoregulatory benefits of microbial “Old Friends” – microorganisms that helped shape our immune systems but which have been largely eliminated from our urban environments.

Green spaces with tree canopy are settings where communities can come together to watch birds and other animals, which can also be catalysts for new conversations and developing feelings of community belonging in the neighbourhoods where we live … just ask dog owners.




Read more:
Reducing stress at work is a walk in the park


So, what about the grass?

Our research did not show a mental health benefit from more bare grassed areas. This does not mean grass is bad for mental health.

Previous research suggests adults are less likely to wander in green spaces that are relatively plain and lacking in a variety of features or amenities.
This may also be partly attributable to preferences for green spaces with more complex vegetation, such as parks that mix grass with tree canopy.

Parks with a variety of vegetation, including trees and grass, may be more attractive for a wider range of outdoor activities than those with few trees.
Author

Furthermore, large areas of bare grass in cities can make built environments more spread-out and less dense. Without tree canopy to shield from the midday sun, this may increase the likelihood of people using cars for short trips instead of walking through a park or along a footpath. The result is missed opportunities for physical activity, mental restoration, and impromptu chats with neighbours. Previous work in the United States suggests this might be why higher death rates were found in greener American cities.

Grassed areas can occupy a large amount of space for surprisingly little mental health benefit.
chuttersnap/Unsplash

Large open areas of grass can be awesome for physical activity and sport, but let’s make sure there is also plenty of tree canopy too, while also thinking about ways to get more people outdoors in green spaces. Here are some suggestions.

Making Australia greener and healthier

As the density of Australian cities continues to increase and more of us live in apartments and/or work in high-rise office blocks, it is great to see strategies to invest in tree cover and urban greening more generally across Australia. Cities with such plans include Sydney, Melbourne, Brisbane, Bendigo, Fremantle, and Wollongong.

You can get involved and have some fun at the same time too. Lots of evidence says gardening is really great for your mental health. So why not grab a mate and spend a couple of hours planting a tree on July 28 for National Tree Day!The Conversation

Both the act of planting a tree and its presence over the decades are good for us.
Amy Fry/flickr, CC BY-NC-SA

Thomas Astell-Burt, Professor of Population Health and Environmental Data Science, NHMRC Boosting Dementia Research Leadership Fellow, University of Wollongong and Xiaoqi Feng, Associate Professor of Epidemiology and NHMRC Career Development Fellow, University of Wollongong

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

Budj Bim’s world heritage listing is an Australian first – what other Indigenous cultural sites could be next?



Ranger Trevor Bramwell on the walk up to the Split Rock art galleries in Cape York’s Quinkan Country in 2017.
Rebekah Ison/AAP

Claire Smith, Flinders University; Gary Jackson, Flinders University, and Jordan Ralph, Flinders University

The Budj Bim Cultural Landscape in south-west Victoria is the first Indigenous Australian landscape to be gazetted on the World Heritage List purely for its cultural values.

This listing breaks an invisible barrier: even the most iconic Indigenous Australian cultural sites, such as Uluru-Kata Tjuta and Kakadu National Parks, were listed for both natural and cultural values.




Read more:
The detective work behind the Budj Bim eel traps World Heritage bid


Could the Budj Bim listing open the door to other Australian Indigenous sites obtaining a World Heritage listing? Here are five that certainly deserve greater attention.

When considering them it’s important to understand how ancestral beings inhabit living Indigenous landscapes, which they created during the era known as the Dreaming.

Today, these beings continue to live in the land. They are seen by Indigenous people as powerful and intelligent, with the capacity to hurt those who don’t act in the right way. They can be in different places at the same time. And they see everything.




Read more:
Australia’s problem with Aboriginal World Heritage


The Dampier Archipelago (including the Burrup Peninsula)

The Dampier Archipelago, 1,550 kilometres north of Perth, has one of the most spectacular rock art landscapes in Australia. The richness and diversity of this art is extraordinary, ranging from small shelters to complexes with thousands of engravings. Some images are similar to those found hundreds of kilometres away in Depuch Island, the Calvert Ranges and Port Hedland, revealing ancient social connections spanning vast distances.

The Ngarda-Ngarlie people believe this area of land was created by the ancestral beings Ngkurr, Bardi and Gardi, who left their marks in its physical features. For instance, the blood of creative beings turned into stains that are now the Marntawarrura, or “black hills”.

Ancient Aboriginal rock art found amongst thousands of drawings and carvings near the Burrup Peninsula in Western Australia.
Robert G. Bednarik/AAP

Baiame’s Ngunnhu (Brewarrina Fishtraps)

The Brewarrina fishtraps, located in the Darling River near Brewarrina in New South Wales, are a clear example of Indigenous science. They offer material evidence of the Ngemba people’s advanced knowledge of dry-stone wall technology, river hydrology and fish ecology.

The Ngemba people believe the ancestral being Baiame revealed the innovative design of the traps by throwing his net over the river. With the help of his two sons, Baiame built the fishtraps in the shape of this net.

Nearly half a kilometre long, the fishtraps’ design and complexity is extraordinary. Dry-stone weirs and ponds were designed to take advantage of the specific configuration of the landscape and seasonal changes in river flows. The pond gates are strategically located to trap fish as they migrate both upstream and downstream. For thousands of years, these distinctive traps have been used to catch fresh water fish.

The fish traps at Brewarrina photographed in 2008.
Dean Lewins/AAP

Ngarrabullgan

Ngarrabullgan, a sacred and dangerous place in north Queensland, is an important example of congruence between Aboriginal traditions and archaeologically recorded changes in behaviours. Excavations show that Aboriginal people began living on Ngarrabullgan more than 37,000 years ago. They stopped camping there about 600 years ago.

There is no evidence of climate or environmental change at this time. Nor is there evidence of depopulation, which could have caused changes in site use. However, the Djungan people believe that a spiritual being called Eekoo lives on Ngarrabullgan (also known as Mt Mulligan). He can cause sickness by throwing stones, hooks or pieces of wood into a person’s body. This does not leave a mark.

Djungan people avoid going near the top of Ngarrabullgan where Eekoo lives to avoid disturbing him. They attribute any sickness when on the mountain to Eekoo.

Ngarrabullgan, also known as Mt Mulligan, in Queensland.
Wikimedia Commons

Quinkan country

The distinctive feature of Quinkan Country in the Cape York Peninsula in North Queensland is the richness, size and density of its Aboriginal paintings and engravings. This country is best known for its depictions of Quinkan spirit beings, tall, slender Timaras and fat-bodied Imjims (or Anurra).

The rock art of Quinkan Country provides insights into Aboriginal occupation of the north-east region of Australia. The cultural traditions, laws, and stories told there were developed over at least 37,000 years.

Ranger Trevor Bramwell points to rock paintings at Split Rock near the Cape York town of Laura in 2017, in the land known as Quinkan Country.
Rebekah Ison/AAP

Western Tasmania Aboriginal Cultural Landscape

The Western Tasmania Aboriginal Cultural Landscape provides evidence of a specialised and more sedentary way of life based on seals, shellfish and land mammals. This unusual Aboriginal way of life began around 2,000 years ago. It continued until the 1830s.

Shell middens in this landscape do not contain the remains of bony fish. However, they do contain “hut depressions”. Sometimes, these are formed into the shape of villages. Circular pits in cobble beaches are near some of these depressions. It is likely that they are hides that were used when hunting seals.

A shell midden in Tasmania.
Candice Marshall/AAP

Other candidates

These places already appear on our national heritage list. There is a plethora of other important ones, both on and off the list, including Mutawintji National Park, Gundabooka National Park and State Conservation area, and Koonalda Cave, on the Nullarbor Plain.

But Aboriginal owners and custodians must be the decision-makers when it comes to proposing a World Heritage listing. They have an inherited right to benefit from a listing – and they hold cultural responsibility for the consequences of it.
Protecting these living landscapes is their responsibility. Increased tourist activity could be a new source of income for them but it could also place cultural landscapes at risk.The Conversation

Claire Smith, Professor of Archaeology, College of Humanities, Arts and Social Sciences, Flinders University; Gary Jackson, Research Associate in Archaeology, Flinders University, and Jordan Ralph, PhD Candidate, Archaeology, Flinders University

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