SoylentNews is people
SoylentNews
from the don't-care-is-not-america[sarcasm] dept.
Submitted via IRC for Bytram
Two degrees decimated Puerto Rico's insect populations
While temperatures in the tropical forests of northeastern Puerto Rico have climbed two degrees Celsius since the mid-1970s, the biomass of arthropods—invertebrate animals such as insects, millipedes, and sowbugs—has declined by as much as 60-fold, according to new findings published today in the Proceedings of the National Academy of Sciences.
The finding supports the recent United Nations Intergovernmental Panel on Climate Change warnings of severe environmental threats given a 2.0 degree Celsius elevation in global temperature. Like some other tropical locations, the study area in the Luquillo rainforest has already reached or exceeded a 2.0 degree Celsius rise in average temperature, and the study finds that the consequences are potentially catastrophic.
"Our results suggest that the effects of climate warming in tropical forests may be even greater than anticipated" said Brad Lister lead author of the study and a faculty member in the Department of Biological Sciences at Rensselaer Polytechnic Institute. "The insect populations in the Luquillo forest are crashing, and once that begins the animals that eat the insects have insufficient food, which results in decreased reproduction and survivorship and consequent declines in abundance."
(Score: 3, Insightful) by Revek on Wednesday October 17 2018, @04:32AM (8 children)
I wonder if they have investigated the effects of long term pesticide use? They couldn't rely on any data from the manufactures. Its not like they would tell the truth.
This page was generated by a Swarm of Roaming Elephants
(Score: 0) by Anonymous Coward on Wednesday October 17 2018, @04:58AM
Like Agent Orange or sumtin?
(Score: 5, Informative) by Anonymous Coward on Wednesday October 17 2018, @09:51AM (6 children)
From The Real Article,
http://www.pnas.org/content/early/2018/10/09/1722477115 [pnas.org]
So yes, they looked at pesticides and it's not a likely cause considering use has greatly decreased. And it was never used in that forest. They also talk about other places and those insect populations.
Anyway.... it's great how people immediately dismiss information like this because it's too alarming without even reading the *FREE* paper. Literally, 2 clicks away from this page.
(Score: 1, Informative) by Anonymous Coward on Wednesday October 17 2018, @10:42AM (4 children)
2011-2012: "Traps were laid out on the ground in the same-sized grid (30 × 24 m), and also left uncovered for 12 h between dawn and dusk before all captured insects were removed and stored in alcohol"
http://www.pnas.org/content/early/2018/10/09/1722477115#ref-22 [pnas.org]
1976-1977: "All traps were uncovered at dawn and left uncovered for 12 h."
http://www.pnas.org/lookup/external-ref?access_num=10.2307/1941511&link_type=DOI [pnas.org]
The day is ~11 hrs long in jan and ~13 hrs long in july for puerto rico.
http://dateandtime.info/citysunrisesunset.php?id=4568127&month=1&year=2012 [dateandtime.info]
The 1970s method seems straightforward enough, but not the 2010s method. There was no 12 hours between dawn and dusk for the new january data, and there is an extra hour either in the morning or evening for them to play with for the july data.
No doubt more (and different) bugs are out at night so I bet the exact timing of the collection period matters a lot. A single hour of night could skew the results. And then there is the question of civil, nautical, or astronomical dusk. Neither paper clarifies but that is another hour earlier or later.
Also in the earlier paper they measured dry mass directly, while in the new paper it was estimated from the length of the insects. The latter method has about a factor of 10 error associated with it that they ignore: https://link.springer.com/article/10.1007/BF02704734 [springer.com]
I also wonder if the insects were equally "dry" for the two papers.
(Score: 0) by Anonymous Coward on Wednesday October 17 2018, @10:54AM
"instead of marking captured lizards by toe clipping, we used Testor’s enamel paint to create small (∼2 mm) spots with different color combinations directly above the dorsal base of the tail."
In the earlier paper the lizards in the area (predators) were being mutilated, while in the current paper only had spots painted on them.
(Score: 3, Informative) by khallow on Wednesday October 17 2018, @02:07PM (2 children)
Doesn't appear to be the problem here.
They're comparing the same times of the year.
The real problem is two-fold. First, we have only two data points. If these observations had been made on an ongoing basis from 1976 to present, with a correlation between say, occurrences of extreme heat and insect populations, they would be on solid ground. We'd then be able to rule out other problems such as invasive species, the various differences in observation, and habitat changes. But a second observation completely without context doesn't tell us that climate change is responsible.
Then we have cited in the paper that a model of tropical insect biomass predicts a far less significant decline in biomass (I guess 20% for the alleged rise in temperature?).
Given the huge decline in ground arthropods, I'd suggest looking at ground-based invasive species like the "red imported fire ant" [wikipedia.org] which was introduced to Puerto Rico by 1982 and now is widespread throughout the island and may by itself explain the decline in insect populations observed.
(Score: 1) by khallow on Wednesday October 17 2018, @02:08PM
(Score: 0) by Anonymous Coward on Wednesday October 17 2018, @02:15PM
Yes, I know. This has nothing to do with the fact the 1970s study started at "dawn" and ran for 12 hours while the 2010s study started at an unknown time at least 12 hours before "dusk". Nor does it address the different possible meanings of dawn/dusk which could mean including (or not) up to an hour of extra darkness.
Could be that. It could be a lot of things, which is why the mere presence of a correlation is not interesting.
(Score: 0) by Anonymous Coward on Wednesday October 17 2018, @12:14PM
Why cant agriculture and pesticide use in nearby crop fields lead to more, or different populations of, insects in the forest? Eg by driving them into a smaller area.