When I first started this blog, my intention was to focus mainly on the effect of climate change on the ecological world. I started out by collecting a number of references to papers that demonstrate range shifts and behavioural changes in various species caused by anthropogenic climate change. That list can be found here. The blog then morphed into a place where I could vent my frustrations about idiotic AGW deniers and more recently focus on Australian politicians and their position on the the scientific consensus that AGW is real and serious. I am pleased to occasionally get back to looking at the impacts of climate change on the natural world because idiotic deniers cannot argue that species haven’t moved or undergone phenological changes because the evidence for these things is unequivocal. Plants, animals, fungi and bacteria cannot be accused of lying or falsifying data or selling out their morals or any other of the ridiculous claims deniers make about scientists. So, to the following article. I welcome any deniers who wish to discuss why the biologcal world is doing what it’s doing. Much as I like going to the circus and watching the clowns throw buckets of confetti at each other.
Tag Archives: range shifts
Climate change will cause widespread global-scale loss of common plants and animals, researchers predict
A new study published in the last few weeks online in PLoS ONE has revealed significant changes in temperature in two Himalayan Valleys, resulting in range shifts in a large number of endemic plant species and changes in species richness. Telwala et al used historical and recent data (1849-50, 2007-2010) on temperature and endemic species’ elevational ranges to perform a correlative study.
From the abstract…
We provide first evidence of warmer winters in the region compared to the last two centuries, with mean temperatures of the warmest and the coldest months may have increased by 0.76±0.25°C and 3.65±2°C, respectively. Warming-driven geographical range shifts were recorded in 87% of 124 endemic plant species studied in the region; upper range extensions of species have resulted in increased species richness in the upper alpine zone, compared to the 19th century. We recorded a shift of 23–998 m in species’ upper elevation limit and a mean upward displacement rate of 27.53±22.04 m/decade in the present study.
So, what do these temperature changes look like?
The thing that is immediately apparent is the temperature has increased at each of the elevations in each of the seasons.
The changes in species distribution, the range shifts, took many forms with some species’ range’s expanding, some contracting, some staying unchanged. Similarly there were difference in the direction of range shifts with a small number losing altitude, some not moving, but the vast majority gaining altitude. The concern of course is that these species, under continued warming, will run out of mountain to climb and become extinct.
The most dramatic range contractions occurred in 6 species, that saw reductions of more than 50% of their historical ranges. These are most likely to be among the first coming under the threat of extinction in a continuously warming environment. In contrast, there were a small number of species that expanded their ranges by more than 100%, possibly colonising areas on the higher elevation end of their range, vacated by more temperature sensitive species.
This is a classic case of specialists losing out to generalists that we are starting to see everywhere where climate change induced range shifts in species is taking place as dictated by both niche theory and disturbance theory in ecology. An excellent but unfortunately paywalled paper that discusses this is. The citation is Joanne Clavel, Romain Julliard, and Vincent Devictor. 2011. Worldwide decline of specialist species: toward a global functional homogenization? Frontiers in Ecology and the Environment 9: 222–228. Click here for the abstract.
What these two graphs demonstrate is that the greatest range shifts in terms of distance moved occurred at the lower elevations and generally more so at the lower margin of the range than the upper. The vast majority of range shifts have also been up the mountains rather than down which is to be expected with increasing temperatures.
An interesting part of this paper is the authors’ discussion of the effects of these range shifts on levels of species richness.
The authors report that the elevation at which 50% of the cumulative species counts per hectare occur has moved upwards in altitude by nearly 260 m. Overall species richness declined by 37%. Despite this decline, species richness in the uppermost 200m elevational band increased by an average of 14.7 species. They report that recent surveys in the study area have revealed 15-18 species that are new arrivals. In a nutshell, some species have disappeared, most have undergone range shifts,, and the whole area is being exploited by generalist species and new arrivals who are able to take advantage of the disturbance created by temperature changes and localised extinctions.
This paper hasn’t been out for long and I have already seen one comment in a forum suggesting that the increase in species richness increase in the upper bands of the study area is evidence that climate change is a good thing. For mind, the only time an increase in species richness is a good thing is when an area is recovering from disturbance back to some semblance of what it was prior to the disturbance. That is not what is happening in the pristine areas of the Himalayas. This is human induced climate change ruining ecosystems through the creation of weed habitats and don’t forget that overall decline in species richness.
Anyone who has ever engaged a hardcore denier in conversation has come up against the “CO2 is plant food” canard. The fervent denier will then tell you about this or that glasshouse study that demonstrated that CO2 increased plant growth. Of course, that’s all fine and good…in the glasshouse, but these kinds of studies are useless for conveying what happens in the real world. In the glasshouse, variables can be tightly controlled so that the only thing being manipulated is CO2. These plants are not subject to other variables like
- increased temperature
- altered rainfall
- changes in water table
- increased nitrification
- increased or changes in pest and disease incidence, especially fungal pathogens
- variable ecosystem responses (e.g. changes in species composition)
- nutritional limiting factors
The clever denier when confronted with this information will resort to highlighting a few studies in cereal crops that purport to show increased biomass and yield, however, these are few and far between. More and more as these studies increase in duration, negative effects begin to appear due to some of the factors I mentioned above and cast doubt on the “CO2 is plant food” meme. For example see here, here, here. Of course, the denier can tell you that many of these things can be overcome by increasing irrigation, fertiliser and pesticides which of course that adds to the environmental and monetary costs of production. In many cases, this is going to be inevitable anyway.
What the denier can’t explain away though is the effect on natural ecosystems. There’s no farmer to go around spraying chemicals, applying water or fertilisers. There’s certainly no way to prevent range shifts. So, are natural ecosystems starting to feel the effect of human induced climate change? The authors of a new study published in Global Ecology and Biogeography certainly think so.
Analysing dendrochronological and isotopic records of trees from all over the globe, Silva and Madhur evaluate the impacts of atmospheric changes on tree growth and intrinsic water use efficiency. They have summarised their key findings as follows.
“ In 37 recently published case studies changes in iWUE were consistently positive, increasing by between 10 and 60%, but shifts in growth varied widely within and among forest biomes. Positive RC values were observed in high latitudes (> 40°N), while progressively lower (always negative) responses were observed toward lower latitudes. Growth rates declined between 15 and 55% in tropical forests. In subtropical sites growth declined by between 7 and 10%, while mixed responses occurred in other regions.”
They conclude, “Over the past 50 years, tree growth decline has prevailed despite increasing atmospheric CO2. The impact of atmospheric changes on forest productivity is latitude dependent (R2 = 0.9, P < 0.05), but our results suggest that, globally, CO2 stimulation of mature trees will not counteract emissions. In most surveyed case studies warming-induced stress was evoked to explain growth decline, but other factors, such as nutrient limitation, could have overridden the potential benefits of rising CO2 levels.”
This study only looked at two aspects of climate change effects being growth and water use efficiency. The effects of changing phenology of pests could be potentially worse as demonstrated by the effect of mountain pine beetles in North America and altered rainfall and water table issues as seen in Western Australia. Given that these issues are manifesting after an average 0.8 degrees temperature increase since the 1950′s, what the hell is it going to look like at 2.0 degrees?
My favourite denier blogger today sent me my regular email full of facepalming moments and general comic relief and the headline today was “Climate Alarmists wrong AGAIN! A new peer reviewed paper….” Hang on! A new peer-reviewed paper? Peer reviewed? But I thought peer review was …..now what did he call it? Oh, that’s right. In an entry from February 10, 2011, he referred to peer review as a “you-scratch-my-back-I’ll-scratch-yours system”. What else? He refers to “the futility of peer review”. He then offers these gems, “So, was Newton peer reviewed when an apple fell on his head and he said: It’s gravity? Was Einstein peer reviewed when he said E=MC2?” That’s pure gold there. Anyway, you can read the whole post here. Of course everyone knows that the Newton apple story is a bit of a myth. While Einstein’s 1905 paper wasn’t officially peer-reviewed, there wasn’t a formal peer review system at the time, it was reviewed by the Journal’s editor and co-editor, Max Planck and Wilhelm Wien, both Nobel prize-winning physicists. But let’s not let accuracy get in the way of a good story. That’s too inconvenient. So, on September 4, 2011 my favourite blogger also said this about peer review, “Peer review: A quasi-sacred process, biased, unjust, unaccountable, incomplete, often insulting, usually ignorant, occasionally foolish, and frequently wrong.” Wow. Strong words.
So why is it then, that deniers who denigrate peer review when it is says the things that kick their wilfully ignorant streaks into gear, champion it when they think it’s supporting their lunacy? Convenience? Dishonesty? Stupidity? All three? So where does the confusion I have mentioned in the title of this blog entry come in? Well, that is the confusion shown by the deniers in their understanding of not only the peer review system but also whether the papers they are alleging support their position, actually do. In that same post of September 4, my favourite denialist blogger also included a link to the “900+ peer-reviewed papers…blah blah blah” that I wrote a piece about here.
So, to the new peer-reviewed paper that shows “Climate Alarmists wrong AGAIN!” (It’s in CAPS so it must be true). The abstract is here. A couple of researchers tested (in a lab) the ability of two species of marine algae to cope with low pH and different salinities in simulated seawater. What they found was that they could and noted in the fulltext version that there were some caveats on that but suggested that these two would do well in estuarine environments and shallow coastal areas under lower pH conditions found with ocean acidification. How this is supposed to be showing up we “alarmists” the blogger doesn’t say, probably because it doesn’t. We know that under a changing environment, generalists are going to do well and specialists are going to suffer. In my short list of papers dealing with range shifts, a number of the papers, also peer-reviewed, demonstrate this very fact. Conceivably, what this new paper that my favourite denialist blogger is championing demonstrates, is that when all the coral bleaches and dies, the algae will be ready and willing to take over. Thanks for the heads up moron.
It never ceases to amaze me that AGW deniers believe that cutting and pasting propaganda is a legitimate way to argue against scientific evidence. Why do they do it? Could it be that propaganda is all they’ve got? As frustrating as it is, it actually makes me smile when I encounter it because it confirms for me that the person doing that has nothing of value to add. They’ve lost the argument. But lets take scientists and politicians, the two groups targeted in most denialist propaganda, out of the equation and focus on natural systems. Individual species of plants, animals, bacteria and fungi don’t have any motives in the climate ‘debate’. They are merely passengers on the climate ride, reacting within whatever physiological and behavioural constraints evolution has bestowed on them and they are reacting. Evidence is growing of more and more species undergoing range shifts in reaction to climate change.
Authors: George Matusik, Giles Hardy and Katinka Ruthrof
Recent, unprecedented, climate-driven forest collapses in Western Australia show us that ecosystem change can be sudden, dramatic and catastrophic. These collapses are a clear signal that we must develop new strategies to mitigate or prevent the future effects of climate change in Australian woodlands and forests. But society’s view of forests is ever-changing: are we willing to understand ecosystems and adapt to changing conditions?
This article was originally published at “The Conversation” on June 5, 2012. To read it in full go here.
The mountain pinebark beetle Dendroctonus ponderosae is a small beetle native to North America from Mexico to British Columbia. This species plays an important ecological role in pine forests by removing old, weak trees, facilitating the growth of saplings. They do this by laying their eggs under the bark of old stressed trees. The larvae, after hatching eat the wood contributing to the tree’s decline. Trees will respond to egg-laying by exuding sap which expels the eggs but also weakens the tree and opens it to infection by pathogenic fungi. In the normal course of things, the ecosystem functions with a high level of predictability.
Recently, pine beetle outbreaks have been more intense, longer in duration and have covered larger and larger areas, resulting in large swathes of mature, usually healthy trees dying. It has been hypothesised that human-induced climate change has been partially responsible. A number of isolated studies in various locations have added weight to that hypothesis. A new study published in the journal Ecology investigates multiple outbreaks over large spatial areas and models these against known climate and weather variables. The authors report that climate is affecting weather patterns resulting in longer droughts, altered rainfall and increased temperature. These in turn are acting as stressors on mature trees,increasing opportunities for beetles to reach plague proportions.
More and more studies of this sort will be comingout in the next few years, adding further weight to the copious evidence for biological effects of climate change that already exist.
Climate scientists have estimated that since 1900, our global average temperature has increased by 0.8 degrees C with most of the warming occurring since 1979 with a 0.2 degrees C/decade increase since 1979. A recent paper published online at Nature by Wolkevitch et al draws on evidence from plant life cycle studies and experiments performed on 1634 species from four continents. It found that some experiments had underestimated the speed of flowering by 8.5 times and growing leaves by 4 times.
“Across all species, the experiments under-predicted the magnitude of the advance – for both leafing and flowering – that results from temperature increases,” the study said, ”Predicting species’ response to climate change is a major challenge in ecology.”
What this study demonstrates is, that because of other factors not considered or under-considered in warming experiments, they fail to accommodate things like a drier soil or other multidimensional drivers. In a nutshell, its worse than we’ve been told.
More and more, research is being published that leaves very little doubt at all that anthropogenic global warming and more generally, climate change is affecting the range distributions of many species of plants, animals and fungi. This in turn alters ecosystems in terms of species composition and diversity. In many instances, effects within species can include declines in genetic diversity which has a potentially devastating effect on species fitness.
Studies into the effects of global warming on range distributions have been undertaken in all sorts of habitats from every continent, looking at species from every Kingdom in the phylogenetic tree. As could be expected, a large number of these studies are undertaken in areas where global warming is known to be most observable. This is in mountainous habitats where species, should they need to move, can only move vertically to remain within their evolved thermal tolerances. A very recent pan-European study published in Science, reports on the observed effect of global warming on species richness and diversity across 66 mountain summits from northern, central and southern Europe.
The researchers from the Global Observation Research Initiative in Alpine Environments programme (GLORIA) headed by Harald Pauli report that increasing species numbers were only found on summits of northern and central Europe. In the Mediterranean alpine region, species numbers were stagnating or declining at nearly all sites. Pauli stated, “Our results showing a decline at the Mediterranean sites is worrying because these are the mountains with a very unique flora and a large proportion of their species occur only there and nowhere else on Earth.”
As mentioned, on the summits further north in Europe, more plant species are prospering. While ignorant deniers will no doubt jump on this sort of thing as evidence to support their stance, as it could be taken to indicate that alpine flowers are performing well there, this would be far too simplistic. Michael Gottfried also from GLORIA’s coordination team said, “I’m afraid that this is not necessarily the case because the newly appearing plants are predominantly more widespread species from lower elevations and will pose increasing competition pressure on the rarer cold-loving alpine flowers.” In other words, more is not necessarily better.
The different results from one end of the study to the other can be attributed to a combination of altered rainfall patterns and topography with some alpine areas essentially series of snowy islands amongst a sea of warmer valleys where altered rainfall patterns are causing added stress. Pauli sums it up thus, “The observed species losses were most pronounced on the lower summits, where plants are expected to suffer earlier from water deficiency than on the snowier high peaks. Climate warming and decreasing precipitation in the Mediterranean during the past decades fit well to the pattern of shrinking species occurrences. Additionally, much of the Mediterranean region is projected to become even drier during the upcoming decades.”
No doubt, future studies will reveal the extent to which this ongoing process becomes catastrophic for many of those species under threat.
I usually don’t visit climate denier blogs because quite frankly, the vast majority of them are just cut and paste jobs of the same old garbage. They keep posting non-science from the same old credibility-free clowns like his royal highness “Lord” Monkton, Anthony Watts, Bob Carter, Pat Michaels, James Delingpole and various others. The overwhelming thing I notice is the over reliance of these various denier blogs on propaganda to try and support their argument. Very rarely do they actually report anything that actually counters the AGW hypothesis on a scientific basis. Don’t get me wrong, they show plenty of graphs of cherrypicked data and plenty of mined quotes taken out of context but thats about it.
One area of research that you will never see mentioned in denier blogs, is that of range shifts in various species caused directly by human induced climate change and global warming. On this blogsite I have highlighted a number of randomly picked studies plus provided a list of peer reviewed papers on this topic. This list is just a mere drop in the ocean of course.
In 2008, there was a seminal paper published in the the highly esteemed journal Nature. This massive study by Rosenzweig et al has found unequivocably that human induced climate change and global warming is responsible for the vast majority of range shifts in so many species. The species included plants, mammals, birds, reptiles, fish, crustaceans, insects, fungi and bacteria. But how many species are we talking about here? Well after excluding data sets where land use change or other factors could have played a part, the researchers report that of the 29500 data series they analysed, more than 90% had shifted their range as a direct response to climate change. Each data series were for periods exceeding 20 years and patterns were analysed using multiple statistical techniques.
My challenge to any deniers that might be reading this is to go to the paper, obtain a full text copy and try and debunk it. Try and be scientific. Good luck.