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Archive for November, 2009

Fires and megafauna: the answer is in the dung

November 20th, 2009 No comments

We recently proposed (Aug/2009) that “The spread of humans, perhaps concomitant with climatic changes, contributed to the mass disappearance of megafauna such as mammoths and other large herbivores (i.e., the Pleistocene-Holocene extinction); this extinction would also have resulted in fuel buildup and the consequent change in fire activity, as suggested by the contemporary effects of megaherbivores.” (Pausas & Keeley 2009; see also Flannery 1994).

Today (20/Nov/2009), in a paper in Science, Gill et al. demonstrate this link between megafauna extinction and fire activity by studying the fossils spores of a coprophilous fungi (Sporormiella) from a lake sediments in Indiana, North America, together with charcoal and pollen from the same sediments (ca. 14,000 years of history). Sporormiella produced spores in the dung of large herbivores, and the amount of spores can be considered an index of the abundance (or biomass) of herbivores vertebrates. The authors demonstrate that the decline in megafauna is associated to an increased fire activity. This also make us to think about the idea of Pleistocene rewilding (Donland et al. 2005) for fuel control and fire reduction.

These papers and other recent ones are putting fire ecology in the front-line of ecology as they demonstrate the strong influence of fire in shaping nature; they emphasize the importance of fire for understanding present, past and future ecosystems as well as global processes. For instance, Nevle & Bird (2008) recently demonstrated that the massive reduction of American natives by the European invasion of America, drastically reduced fire activity and the consequent increase in forest (carbon sequestration) contributed to the ca 2% global reduction in atmospheric CO2. Despite the importance of fire in the global context, they are still poorly represented in global models (Bowman et al. 2009).

References

Bowman D.M.J.S. et al. (2009). Fire in the Earth System. Science, 324, 481-484.

Donlan C.J. et al. (2006). Pleistocene Rewilding: an optimistic agenda for 21st century conservation. The American Naturalist 168: 660-681

Flannery T. (1994). The Future Eaters: An Ecological History of the Australasian Lands and People. Reed Press, Port Melbourne, Australia.

Gill JL et al. (2009). Pleistocene Megafaunal Collapse, Novel Plant Communities, and Enhanced Fire Regimes in North America. Science 326: 1100-1103.

Nevle R.J. & Bird D.K. (2008). Effects of syn-pandemic fire reduction and reforestation in the tropical Americas on atmospheric CO2 during European conquest. Palaeogeography, Palaeoclimatology, Palaeoecology 264: 25-38.

Pausas J.G. & Keeley J.E. (2009). A burning story: The role of fire in the history of life. BioScience 59: 593-601. [caliber] [BioOne] [doi] [pdf]

Fire ecology publications

November 14th, 2009 No comments

Journals:

Papers of fire ecology can be found in any ecology journal; in addition there some specific journal on fire science:

Reference databases:

Prominent books:

  • Bond & van Wilgen (1996) Fire and Plants [preview]
  • Whelan (1995) The ecology of fire [preview]

[Update] new book: Keeley et al. (2012) [link]

Convergent evolution

November 8th, 2009 No comments

Images from two different tree species (A and B), from different Families (and different Orders), taken in different continents…

A1
tree1sm
A2
treebark1sm
A3
bark1sm
B1
tree2sm
B2
bark2sm

The thick bark offers protection to fire and thus these species are both adapted to live in fire-prone ecosystems [1].

Can you guess the species name of A and B?    [ Answer: A | B ]

Notes

[1] See also: The ecology of bark thickness | The ecology of bark thickness (2): another twist

 

Ciencia básica en España

November 6th, 2009 No comments

Es increible ver que personas con responsabilidad política y con capacidad de influencia en nuestra sociedad, tiene tan poco interés por la ciencia básica, que es precisamente el motor del conocimiento y el desarrollo de nuestra sociedad. Seguramente el conocimiento es lo que nos hace más humanos; despreciar ese conocimiento es despreciar a la humanidad. Cualquier país que aspire a ser puntero debe invertir en ciencia básica, que es el primer paso a la tecnología y al desarrollo. Los países sin ciencia básica sólo pueden copiar lo que hacen los otros, e ir siempre por dentras en todo. Aquí un ejemplo de ese desprecio por la ciencia en la clase política:

“La ministra ha decidido reorientar el gasto de investigación para que el desequilibrio entre universidad y sector privado no sea tan desigual; la razón es plausible siempre que se tenga el coraje y la autoridad política para explicarla. Esa razón radica en el hecho de que la investigación universitaria tiene un componente de básica que no puede seguir subvencionándose en tiempos de crisis y en pleno siglo XXI, por la sencilla razón de que lo que necesita nuestra sociedad son proyectos de investigación aplicada que añadan valor, riqueza y empleo a nuestra economía.”  –  Extraido de: “Arrimar el hombro“, Juan Carlos Rodríguez Ibarra (PSOE, ex-presidente de la Junta de Extremadura), el País, 26 Oct 2009.

Réplica: “Sobre la investigación“, Miguel Maravall Rodríguez (CSIC), el País 29 Oct 2009.

Ver también la crítica de la decisión de la ministra en la editorial de Nature 462, 137-138 (12 Dec 2009): No turning back [traducción en un blog de El País: Sin vuelta atrás]