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Posts Tagged ‘fauna’

Generalized fire strategies in plants and animals

October 4th, 2018 No comments

One of the unifying approaches in ecology is to search for common strategies, that is, to group species sharing mechanisms and responses to environmental factors and disturbances. Plant strategies to persist in fire-prone ecosystems (and the traits involved) are now quite well known [1]. However, less is known about fire strategies in animals, despite many fire-prone ecosystems harbor a very rich fauna [2]. This difference in knowledge is probably due to the intrinsic differences between plants (immobile) and animals (mobile) [2]. However, there is a demand for unifying plant an animals paradigms in order to better asses biodiversity in fire-prone ecosystems [3]. In a recent paper [4] I am providing an unifying framework by emphasizing the similarities between plants and animals in relation to the mechanisms for living in fire-prone ecosystems. To do so, I propose a very simple fire strategy scheme that should be valid for both plants and animals (Table 1). The advantage of having a unified framework of fire strategies include: (1) we can learn how species respond to fire from a great diversity of life forms; (2) animal and plant ecologists can benefit from shared expertise in fire responses (some common strategies in plants may be overlooked in animals, or vice-versa); (3) we could better predict changes in plant-animal interactions with fire regime changes, and (4) we could better assess and generalize the effects of fire on biodiversity. I hope this framework would facilitate finding knowledge gaps and directing future research for gaining a better understanding of the role of fire on biodiversity.

Table 1. Generalized mechanisms of species response to fire (strategy), their fire dynamics and persistence scale, and the prevalence for animals and plants in fire prone ecosystems (low, moderate, and high). The last column refers to the fire characteristics where this strategy is most likely to occur (‘high’ and ‘low’ refers to fire intensity). [4]

Fig. 1. The rhea (Rhea americana) has a cryptic coloration in postfire environments, when sitting in the ground, the neck cannot be differentiated from a burned stem. Photo: JG Pausas

 

Fig. 2. Charaxes jasius colonizing the middle of a burnt area 10 days after the wildfire that burned with very high intensity in NE Spain (note that only thick branches remained). Photo: JG Pausas.

References

[1] Keeley J.E., Bond W.J., Bradstock R.A., Pausas J.G. & Rundel P.W. 2012. Fire in Mediterranean Ecosystems: Ecology, Evolution and Management. Cambridge University Press. [the book]  

[2] Pausas J.G., Parr C.L. 2018. Towards an understanding of the evolutionary role of fire in animals. Evolutionary Ecology 32: 113–125. [doi | pdf]  

[3] Kelly L.T., Brotons L, Giljohann K.M., McCarthy M.A., Pausas J.G., Smith A.L. 2018. Bridging the divide: integrating animal and plant paradigms to secure the future of biodiversity in fire-prone ecosystems. Fire 1(2): 29. [doi | mdpi | pdf]  

[4] Pausas J.G. 2018. Generalized fire response strategies in plants and animals. Oikos [doi | wiley | pdf | oikosblog]

 

Fire benefits flower beetles

June 28th, 2018 No comments

For two years we sampled invertebrates after two large wildfires in eastern Spain and demonstrate that two flower beetle species, Protaetia morio and P. oblonga (Cetoniidae; Fig. 1 & 2 below), show a pyrophilous behaviour [1]. These beetles were much more numerous after the fires than in unburnt plots around the fire perimeter; in addition, these species tended to increase in number with the distance from the fire perimeter and with fire recurrence (Fig. 3 below). These results suggest that local populations survived the fire as eggs or larvae protected in the soil, and then they were favoured postfire (i.e., population size increased, compared with unburnt zones). We propose that this could be driven by the reduction of their predator populations, as vertebrates that feed on these beetles are disfavored by fire. That is, the results suggest that these flower beetle species benefit from fire because fire disrupts antagonistic interactions with their predators (predation release hypothesis).


Fig. 1. Protaetia morio: eggs, larva, pupal, and adult (photos: S. Montagud); pitfall trap full of Protaetia beetles (bottom left).


Fig. 2: Protaetia morio (male and famale) and Protaetia oblonga (male and female)

 

Fig. 3: Abundance (number of individuals) of Protaetia morio one and two years after fire (from two fires that occurred in 2012). Green: Unburnt; Yellow: Burnt edge (< 700 m from the fire perimeter); Orange: Burnt center (> 1.3 km from the fire perimeter). P. oblonga showed a similar pattern. For details, see [1].

Reference 
[1] Pausas, J.G., Belliure, J., Mínguez, E. & Montagud, S. (2018) Fire benefits flower beetles in a mediterranean ecosystem. PLoS ONE, 13: e0198951. [doi | plos | pdf]

 

Fire-dependent and fire-adapted animals

January 17th, 2018 No comments

Plants show a plethora of adaptive traits for persisting under recurrent fires [1]. However, fire-prone ecosystems also harbor a rich fauna, and little is know about their adaptive traits for fire survival. In a recent paper [2] we review this issue and suggest that many animals are adapted to the open habitats generated by fire; yet although they require fires for survival (fire-dependent animals), they do not necessarily show any specific morphological adaptation to fire. However, these species would become very rare or even extinct in the absence of fires generating their habitat. In addition, in some cases, animals from these fire-prone ecosystems show specific fire adaptation (fire-adapted animals). Currently, there are few examples of morphological adaptations to fire in the animal kingdom (reviewed in [2]). In part this may simply reflect the low number of studies that have attempted to look for fire adaptations. We propose that there remains significant scope for research on fire adaptations in animals, and especially in relation to the rich behavioral traits that allow persistence in fire-prone ecosystems. This is because, in contrast to plants, most animals are unitary organisms with reduced survival when directly burnt by fire, but are mobile and can move away from the fire. That is, behavioral traits are poorly explored under the framework of the evolutionary fire ecology and may provide a rich source for fire adaptations. Developing this understanding is critical to better understand the role of fire in determining the biodiversity of our landscapes.

Photo 1: An owl hunting in the fire front (fire-foraging) at Aransas National Wildlife Refuge in Texas (Photo: Jeffrey Adams/USFWS; from www.fws.gov).

 

Photo 2: The rhea (Rhea americana) is a flightless bird living in Brazilian savannas; it has a cryptic colors in postfire environments, when it sits in the ground in cannot be differentiated from burn stems (Photo: JG Pausas, 2009).

 

References

[1] Keeley J.E., Bond W.J., Bradstock R.A., Pausas J.G. & Rundel P.W. 2012. Fire in Mediterranean Ecosystems: Ecology, Evolution and Management. Cambridge University Press. [the book]

[2] Pausas J.G., Parr C.L. 2018. Towards an understanding of the evolutionary role of fire in animals. Evolutionary Ecology. [doi | pdf]  

More on fire and evolution

 

Odena fire: first visitors

August 10th, 2015 1 comment

The 27th of July a fire in Òdena (Anoia, central Catalonia, NE Spain) burned ca. 1200 ha, mainly of Pinus halepensis. It was a crown fire of relatively high intensity. Twelve days after the fire, everything was still black, there were not yet signs of any plant resprouting; however, there were already few visitors. Here a couple of examples.

 

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Charaxes jasius (left) and Parasteropleurus (Steropleurus) perezii (right) on recently burned trees (Photos by A. Mazcuñan and P. Mazcuñan, respectively).

 

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