Give way to the invader

25 01 2012

By weird coincidence, Salvador Herrando-Pérez (student blogger extra-ordinaire – see his previous posts on evolution, pollination, bird losses, taxonomic inflation, niche conservatism, historical biogeography, ecological traps and ocean giants) has produced a post this week expanding on the problem of roads. Also weirdly coincidental is that both Salva and I are in his home country of Spain this week.

Australia’s > 800,000-km road network would go 60 times around the equator of our planet. Confined to the boundaries of any one country, roads are a conspicuous component of the landscape, and shape the dispersion, survival and reproduction of many plants and animals in urban and remote areas.

Those who drive (or are driven by) will be familiar with the image of a crushed kangaroo on the roadside (a hedgehog in Europe), or the sticky mosaic of insects smashed against the windscreen after a high-speed run. Mortality by collision is one of the many effects that roads can have on the demography of organisms – including humans. Those effects encompass

  • physical alteration of terrestrial and aquatic habitats,
  • chemical pollution leakage during road construction and maintenance, and from asphalt compounds during storms,
  • alteration of animal behaviour (e.g., change in home range, or in patterns of flight or vocalisation),
  • access to remote areas by hunters, fishermen and gatherers in general, and
  • intense habitat fragmentation1-3.

However, some species get around those negative impacts by using the roads as pathways to new territories, thereby eluding barriers like seas, mountains, rivers, dense vegetation, or competition for vital resources with other species. Read the rest of this entry »





Slicing the second ‘lung of the planet’

12 12 2011

© WWF

Apologies for the slow-down in postings this past week – as many of you know, I was attending the International Congress for Conservation Biology in Auckland. I’ll blog about the conference later (and the stoush that didn’t really occur), but suffice it to say it was very much worthwhile.

This post doesn’t have a lot to do per se with the conference, but it was stimulated by a talk I attended by Conservation Scholar Stuart Pimm. Now, Stuart is known mainly as a tropical conservation biologist, but as it turns out, he also is a champion of temperate forests – he even sits on the science panel of the International Boreal Conservation Campaign.

I too have dabbled in boreal issues over my career, and most recently with a review published in Trends in Ecology and Evolution on the knife-edge plight of boreal biodiversity and carbon stores. That paper was in fact the result of a brain-storming session Navjot Sodhi and I had one day during my visit to Singapore sometime in 2007. We thought, “It doesn’t really seem that people are focussing their conservation attention on the boreal forest; how bad is it really?”.

Well, it turns out that the boreal forest is still a vast expanse and that there aren’t too many species in imminent danger of extinction; however, that’s where the good news ends. The forest itself is becoming more and more fragmented from industrial development (namely, forestry, mining, petroleum surveying and road-building) and the fire regime has changed irrevocably from a combination of climate change and intensified human presence. You can read all these salient features here.

So, back to my original thread – Stuart gave a great talk on the patterns of deforestation worldwide, with particular emphasis on how satellite imagery hides much of the fine-scale damage that we humans do to the world’s great forests. It was when he said (paraphrased) that “50,000 km2 of boreal forest is lost each year, but even that statistic hides a major checkerboard effect” that my interest was peaked. Read the rest of this entry »





Want a cool conservation job in beautiful southern Australia?

14 12 2010

I was asked to post this cool-sounding job on ConservationBytes.com – relevant punters welcome to respond.

http://goo.gl/9YjGn

Australian Wildlife Conservancy (AWC) is a non‐profit organisation dedicated to the conservation of Australia’s threatened wildlife and their habitats. AWC now owns and manages more land than any other private conservation organisation in Australia ‐  21 properties, covering more than 2.6 million hectares ‐ protecting more than 1,200 fauna species through active land management informed by strategic scientific research.

AWC is seeking an experienced and committed ecologist who will be pivotal in the development and implementation of the conservation and science program throughout south‐eastern Australia. The position will be based at Scotia Wildlife Sanctuary (where on‐site accommodation will be provided), but will include work at other AWC sanctuaries, especially Kalamurina (Lake Eyre), Buckaringa (Flinders Ranges), Yookamurra (Riverlands), Dakalanta (Eyre Peninsula), Bowra (Mulga Lands) and North Head (Sydney) sanctuaries.

Scotia is a large property (65,000 ha) that lies on the NSW‐SA border between Wentworth and Broken Hill, and includes Australia’s largest area free of foxes, cats and rabbits (8,000 ha) and where seven regionally extinct species have been reintroduced (bilby, boodie, woylie, bridled nailtail wallaby, numbat, greater stick‐nest rat, mala and black‐eared miner). In addition, the property has outstanding conservation values because it protects habitats, in good condition, that have been extensively cleared in western NSW.

Read the rest of this entry »





Global rates of forest loss – everyone’s a bastard

29 04 2010

© A. Hesse

I’ve written rather a lot about rates of forest loss around the world, including accumulated estimates of tropical forest loss and increasing fragmentation/loss in the boreal forest (see Bradshaw et al. 2009 Front Ecol Evol & Bradshaw et al. 2009 Trends Ecol Evol). For the tropics in particular, we used the index that an area of rain forest about the size of Bangladesh (> 15 million hectares) was disappearing each year, and in Russia alone, annual decline in forest area averaged 1.1 million hectares between 1988 and 1993. Mind boggling, really.

But some of these estimates were a bit old, relied on some imprecise satellite data, and didn’t differentiate forest types well. In addition, many have questioned whether the rates are continuing and which countries are being naughty or nice with respect to forest conservation.

It was great therefore when I came across a new paper in PNAS by Hansen & colleagues entitled Quantification of global gross forest cover loss because it answered many of the latter questions.

Part of the problem in assessing worldwide forest cover loss in the past was the expense of satellite imagery, access problems, data storage and processing issues. Happily, new satellite streams and easing of access has rectified many of these limitations. Hansen & colleagues took advantage of data from the MODIS sensor to create a stratification for forest cover loss. They then used the Landsat ETM+ sensor as the primary data for quantifying gross forest cover loss for the entire planet from 2000 to 2005. They defined ‘forest cover’ as “… 25% or greater canopy closure at the Landsat pixel scale (30-m × 30-m spatial resolution) for trees > 5 m in height”.

For your reading pleasure (and conservation horror), the salient features were: Read the rest of this entry »





Conservation Scholars: David Lindenmayer

10 09 2009

The Conservation Scholars series highlights leaders in conservation science and includes a small biography, a list of major scientific publications and a Q & A on each person’s particular area of expertise.

David LindenmayerOur fourteenth Conservation Scholar is one of Australia’s better known conservation ecologists: David Lindenmayer. David has been battling for landscape ecology and conservation science to be taken seriously in this country for over 30 years. I recently featured David here at ConservationBytes.com on the importance of incorporating ecological knowledge into Australian bushfire policy, but here’s a more comprehensive coverage of his legacy.

Biography

I am a Research Professor at the Fenner School of Environment & Society at The Australian National University (ANU). I have worked at the ANU for over 17 years and have developed a speciality for establishing and maintaining large-scale, long-term empirical studies. These span wet forests (in Victoria), plantation forests (at Tumut in southern NSW), temperate woodlands (throughout south-western NSW) and coastal heathlands (at Jervis Bay Territory, southern NSW). We examine the response of different groups of biota (birds, mammals, reptiles, frogs, invertebrates and plants) to human or natural interventions in these studies – e.g., logging, plantation development, agricultural and revegetation, fire (wildfire and prescribed burning). We also have projects that attempt to integrate data and ecological insights across these major projects. These major programs have many (> 75) live projects embedded within them, including an array of post-graduate students.radiotracking1

The work we do has some key themes. First, it needs to be underpinned by careful statistical design and we have 3 professional statisticians in our group that have critical experimental design roles in all of our studies. Second, we build significantly upon long-term datasets to quantify longitudinal responses of biota to agents of change. Third, we work closely with land managers and government agencies to increase the chances of our work being adopted on the ground. Fourth, and related to the previous point, we work very hard to communicate our empirical results to a broad audience by publishing semi-popular books and other kinds of communication products.

Our group currently comprises ~ 30 people and the younger scientists in the team are a truly exciting part of its dynamism. Indeed, the best research is usually done by post-graduate researchers!! Our hope is to maintain the research and teaching momentum that we have generated over the past decade to keep the group a vibrant, active and forward-thinking one for several decades to come.

Major Publications

It is difficult to choose some papers above others. But I do like the major empirical ones we have done because large synthesis of field data are not common these days – in an age where the emphasis is on short, ‘newsy’ pieces. I also like writing books and longer review articles because these are a chance to pull together a lot of information and make sense of the literature out there.

Questions and Answers

radiotracking21. You are probably best known for your work on vertebrate responses to forested landscape change. What kind of data and studies are needed to gauge how biodiversity responds to such changes?

It is clear to me that there is a paucity of large-scale, long-term datasets really to develop an empirical understanding of what is happening in a changing world. This is what our group does really well I think, so it is a real privilege to be able to do that.

2. Your book, Practical Conservation Biology, is a great introduction to applied conservation. Can you describe what you mean by ‘practical’ and how aspiring students need to approach conservation science?

The aim of the PCB book was to provide students with the thinking and some (and I stress just some) of the tools to tackle real world problems. I am not sure that we succeeded in doing this, but it was a good thing to attempt. I also think it was important to showcase Australian conservation biology because there are some many outstanding researchers and practitioners in this country.

3. Fire management is a ‘hot’ issue (excuse the pun) in Australia and beyond, yet there still seems to be little uptake of good fire disturbance ecology by policy makers. What do we need to be doing differently at the policy level, and how can we facilitate better uptake of landscape disturbance ecology?

This is a tough question because so often fire management issues are hijacked by the emotion that is associated with major natural disturbance events. The issue here is that the science of fire and the science of conservation and environmental management need to be better intersected to examine how to best tackle resource management problems. Policy somehow needs to remain cold to all the emotion that humans throw, often illogically at resource management problems. Otherwise I see that policy making in crisis mode will risk perverse outcomes that will be poor management practice and have negative effects on biodiversity.

4. In your opinion, what are the some of the best ways Australia can improve its poor environmental record and reclaim some of its dwindling biodiversity heritage?

Australian needs to get serious about properly resourcing environmental management and biodiversity conservation. We have endless reports about what to do, yet this rarely transfers to serious things on the ground. Nor does environmental legislation really protect the environment and biodiversity. We also need to get serious about long-term datasets to get somewhere sensible with understanding long-term changes in biota.

CJA Bradshaw

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Fragmen borealis: degradation of the world’s last great forest

12 08 2009
© energyportal.eu

© energyportal.eu

I have the dubious pleasure today of introducing a recently published paper of ours that was at the same time both intellectually stimulating and demoralising to write. I will make no apologies for becoming emotionally involved in the scientific issues about which my colleagues and I write (as long as I can maintain with absolute sincerity that the data used and conclusions drawn are as objectively presented as I am capable), and this paper probably epitomises that stance more than most I’ve written during my career.

The topic is especially important to me because of its subtle, yet potentially disastrous consequences for biodiversity and climate change. It’s also a personal issue because it’s happening in a place I used to (many, many years ago) call home.

Despite comprising about a third of the world’s entire forested area and harbouring some of the lowest human densities anywhere, the great boreal forest that stretches across Alaska, Canada, Scandinavia and a huge chunk of Russia is under severe threat.

Surprised that we’re not talking about tropical deforestation for once? Surprised that so-called ‘developed’ nations are pilfering the last great carbon sink and biodiversity haven left on the planet? If you have read any of the posts on this blog, you probably shouldn’t be.

The paper today appeared online in Trends in Ecology and Evolution and is entitled Urgent preservation of boreal carbon stocks and biodiversity (by CJA Bradshaw, IG Warkentin & NS Sodhi). It’s essentially a review of the status of the boreal forest from a biodiversity perspective, and includes a detailed assessment of the degree of its fragmentation, species threat, climate- and human-influenced disturbance regime, and its carbon sequestration/emission status. I’ll summarise some of the main findings below:

borealfire

© NASA

  • Russia contains ~53 % of the boreal forest, followed by Canada (25 %), USA (18 %, mostly in Alaska), Sweden (2 %) and Finland and Norway (~1 % each); there are small areas of boreal forest in northern China and Mongolia.
  • Fire is the main driver of change in the boreal forest. Although clearing for logging and mining abounds, it pales in comparison to the massive driver that is fire.
  • There is evidence that climate change is increasing the frequency and possibly extent of fires in the boreal zone. That said, most fires are started by humans, and this is particularly the case in the largest expanse in Russia (in Russia alone, 7.5 and 14.5 million hectares burnt in 2002 and 2003, respectively).
  • While few countries report an overall change in boreal forest extent, the degree of fragmentation and ‘quality’ is declining – only about 40 % of the total forested area is considered ‘intact’ (defined here as areas ≥ 500 km2, internally undivided by things such as roads, and with linear dimensions ≥ 10 km).
  • Russian boreal forest is the most degraded and least ‘intact’, and has suffered the greatest decline in the last few decades compared to other boreal countries.
  • Boreal countries have only < 10 % of their forests protected from wood exploitation, except Sweden where it’s about 20 %.
  • There are over 20000 species described in the boreal forest – a number much less than that estimated for tropical forests even of much smaller size.
  • 94 % of the 348 IUCN Red Listed boreal species are considered to be threatened with extinction, but other estimates from local assessments compiled together in 2000 (the United Nations’ Temperate and Boreal Forest Resources Assessment) place the percentages of threatened species up to 46 % for some taxa in some countries (e.g., mosses in Sweden). The latter assessment placed the Fennoscandian countries as having the highest proportions of at-risk taxa (ferns, mosses, lichens, vascular plants, butterflies, birds, mammals and ‘other vertebrates’), with Sweden having the highest proportion in almost all categories.
  • Boreal forest ecosystems contain about 30 % of the terrestrial carbon stored on Earth (~ 550 Gigatonnes).
  • © BC Ministry For Range/L. Maclaughlan

    Warmer temperatures have predisposed coniferous forest in western Canada to a severe outbreak of mountain pine beetle (Dendroctonus ponderosae) extending over > 13 M ha. © BC Ministry For Range/L. Maclaughlan

  • Mass insect outbreaks killing millions of trees across the entire boreal region are on the rise.
  • Although considered in the past as a global carbon sink, recent disturbances (e.g., increasing fire and insect outbreak) and refinements of measurement mean that much of the area is probably a carbon source (at least, temporarily).
  • A single insect outbreak in western Canada earlier this decade thought to be the direct result of a warming planet contributed more carbon to the atmosphere than all of that country’s transport industry and fire-caused release combined.
  • Current timber harvest management is inadequately prepared to emulate natural fire regimes and account for shifting fire patterns with climate change.
  • No amount of timber management can offset the damage done by increasing fire – we must manage fire better to have any chance of saving the boreal forest as a carbon sink and biodiversity haven.

Those include the main take-home messages. I invite you to read the paper in full and contact us (the authors) if you have any questions.

CJA Bradshaw

Full reference: Bradshaw, CJA, IG Warkentin, NS Sodhi. 2009. Urgent preservation of boreal carbon stocks and biodiversity. Trends in Ecology and Evolution DOI: 10.1016/j.tree.2009.03.019

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Eastern Seaboard Climate Change Initiative

30 04 2009
© A. Perkins
© A. Perkins

I’ve just spent the last few days in Sydney attending a workshop on the Eastern Seaboard Climate Change Initiative which is trying to come to grips with assessing the rising impact of climate change in the marine environment (both from biodiversity and coastal geomorphology perspectives).

Often these sorts of get-togethers end up doing little more than identifying what we don’t know, but in this case, the ESCCI (love that acronym) participants identified some very good and necessary ways forward in terms of marine research. Being a biologist, and given this is a conservation blog, I’ll focus here on the biological aspects I found interesting.

The first part of the workshop was devoted to kelp. Kelp? Why is this important?

As it turns out, kelp forests (e.g., species such as Ecklonia, Macrocystis, Durvillaea and Phyllospora) are possibly THE most important habitat-forming group of species in temperate Australia (corals and calcareous macroalgae being more important in the tropics). Without kelp, there are a whole host of species (invertebrates and fish) that cannot persist. The Australian marine environment is worth something in the vicinity of $26.8 billion to our economy each year, so it’s pretty important we maintain our major habitats. Unfortunately, kelp is starting to disappear around the country, with southern contractions of Durvillaea, Ecklonia and Hormosira on the east coast linked to the increasing southward penetration of the East Australia Current (i.e., the big current that brings warm tropical water south from Queensland to NSW, Victoria and now, Tasmania). Pollution around the country at major urban centres is also causing the loss or degradation of Phyllospora and Ecklonia (e.g., see recent paper by Connell et al. in Marine Ecology Progress Series). There is even some evidence that disease causing bleaching in some species is exacerbated by rising temperatures.

Some of the key kelp research recommendations coming out of the workshop were:

  1. Estimating the value of kelp to Australians (direct harvesting; fishing; diving)
  2. Physical drivers of change: understanding how variation in the East Australian Current (temperature, nutrients) affects kelp distribution; understanding how urban and agricultural run-off (nutrients, pollutants, sedimentation) affects distribution and health; understanding how major storm events (e.g., East Coast Lows and El Niño-Southern Oscillation) affects long-term persistence
  3. Monitoring: what is the distribution and physical limits of kelp species?; how do we detect declines in ‘health’?; what is the associated biodiversity in kelp forests?
  4. Experimental: manipulations of temperature/nutrients/pathogens in the lab and in situ to determine sensitivities; sensitivity of different life stages; latitudinal transplants to determine localised adaption
  5. Adaptation (management): reseeding; managing run-off; managing fisheries to maintain a good balance of grazers and predators; inform marine protected area zoning; understanding trophic cascades

The second part of the discussion centred on ocean acidification and increasing CO2 content in the marine environment. As you might know, increasing atmospheric CO2 is taken up partially by ocean water, which lowers the availability of carbonate and increases the concentration of hydrogen ions (thus lowering pH or ‘acidifying’). It’s a pretty worrying trend – we’ve seen a drop in pH already, with conservative predictions of another 0.3 pH drop by the end of this century (equating to a doubling of hydrogen ions in the water). What does all this mean for marine biodiversity? Well, many species will simply not be able to maintain carbonate shells (e.g., coccolithophore phytoplankton, corals, echinoderms, etc.), many will suffer reproductive failure through physiological stress and embryological malfunction, and still many more will be physiologically stressed via hypercapnia (overdose of CO2, the waste product of animal respiration).

Many good studies have come out in the last few years demonstrating the sensitivity of certain species to reductions in pH (some simultaneous with increases in temperature), but some big gaps remain in our understanding of what higher CO2 content in the marine environment will mean for biota. Some of the key research questions in this area identified were therefore:

  1. What is the adaptation (evolutionary) potential of sensitive species? Will many (any) be able to evolve higher resistance quickly enough?
  2. In situ experiments outside the lab that mimic pH and pCO2 variation in space and time are needed to expose species to more realistic conditions.
  3. What are the population consequences (e.g., change in extinction risk) of higher individual susceptibility?
  4. Which species are most at risk, and what does this mean for ecosystem function (e.g., trophic cascades)?

As you can imagine, the conversation was complex, varied and stimulating. I thank the people at the Sydney Institute of Marine Science for hosting the fascinating discussion and I sincerely hope that even a fraction of the research identified gets realised. We need to know how our marine systems will respond – the possibilities are indeed frightening. Ignorance will leave us ill-prepared.

CJA Bradshaw

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