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Posts Tagged ‘conservation’

Wildfires as an ecosystem service

May 7th, 2019 No comments

Wildfires are often viewed as destructive disturbances. In a recent paper we propose that when including both evolutionary and socioecological scales, most ecosystem fires can be understood as natural processes that provide a variety of benefits to humankind [1]. Wildfires provide open habitats that enable the evolution of a diversity of shade-intolerant plants and animals that are a source of products used by humans since long ago. Wildfires also regulate pests and catastrophic fires, contribute to the regulation of the water and carbon cycles, and could help plants in their adaptation to novel climates. That is, there are many provisioning, regulating, and cultural services that we obtain from wildfires (box below).  Prescribed fires are a tool for mimicking the ancestral role of wildfires in a highly populated world.

Figure: Schematic representation of the factors occurring at the evolutionary (green square) and at the socioecological (yellow square) scale associated with fire regimes and ecosystem services. Natural (historical) wildfire regimes create open habitats that can promote specific adaptations, biodiversity, and overall functioning in fire-prone ecosystems; these are the supporting services necessary for the production of all other services (table below). Decisions and policies may modify fire regimes (anthropogenic fire regimes) modulating ecosystem functioning and services (socioecological feedback); that is, policy decisions may switch between maintaining ecosystem services (stabilizing feedback) or generating unsustainable fire regimes (disruption of the feedback). Decisions and policies (bottom right corner) include fire and landscape management decisions, but also include socioeconomic changes that have implications on fire regimes (eg rural abandonment [2]). From [1].

Examples of ecosystem services provided by recurrent wildfires to early and to contemporary societies. For more details, see [1]:

  • Provisioning services:
    – Provide open spaces for pastures, agriculture, and hunting
    – Stimulate germination of desirable annual ‘crops’ postfire
    – Provide carbohydrates from underground plant organs
    – Provide craft and basketry material (resprouts)
    – Maintaining open spaces for grazing and hunting
    – Provide essences, medicines, flowers (ornamental)
  • Regulating services
    – Pest control for humans and livestock
    – Reduce catastrophic wildfires
    – Accelerates species replacement in changing conditions
    – Enhance flowering and pollinator activity
    – Water regulation
    – Carbon balance
  • Cultural services
    – Spiritual, inspirational
    – Ecotourism in open ecosystems
    – Recreational hunting
    – Scientific knowledge on the origin of biodiversity
    – Knowledge on ancestral fire management techniques

 

Cover of the June 2019 issue of Frontiers in Ecology & Environment (17, 6) where our papers is featured. California poppy (Eschscholzia californica) flowering postfire enhances pollination.

 

Illustrating ecosystems services by fire is not easy; here are some examples of pictures I received to potentially illustrate this paper; most of them did not finally go to the paper. Thanks to the contributes! – [click the photo to enlarge]

 

References

[1] Pausas J.G. & Keeley J.E. 2019. Wildfires as an ecosystem service. Frontiers in Ecology and Environment 17: 289-295 [doi | pdf | summary for managers]

[2] Pausas J.G. & Fernández-Muñoz S. 2012. Fire regime changes in the Western Mediterranean Basin: from fuel-limited to drought-driven fire regime. Climatic Change 110: 215-226. [doi | springer | pdf]  

 

The long shadow of Humboldt

January 15th, 2019 No comments

Behind the paper “Humboldt and the reinvention of nature” [1]. Text simultaneously published here and in JEcologyBlog.com

It all started when I was reading an excellent book by Andrea Wulf entitled The Invention of Nature: Alexander von Humboldt’s New World. The book provides many details about Humboldt’s fascinating life and the wide-ranging influence he had on science and society. When reading the book, you can easily understand the unquestionable role Humboldt played in the history of ecology and biogeography. One of his many contributions to science was to set the basis for explaining how environmental factors affect species distribution; for example, he demonstrated that vegetation systematically varies across the world with climate and showed the ecological similarities between altitude and latitude.
 

Fig. 1. Vegetation of Chimborazo (Ecuador) by Humboldt and Bonpland (1807).

 
A question that came to my mind was not covered by the book; namely, to what extent does Humboldt’s view bias our vision of nature? This is relevant because many classical naturalists and ecologists, such as Henry David Thoreau, Charles Darwin, George Perkins Marsh, John Muir, Rachel Carlson, Frederic E. Clements, and Henry A. Gleason, were all inspired by Humboldt. By spreading a vision, they shaped what is today mainstream ecology and the environmental movement. The current emphasis on the role of climate and soil in many ecological and evolutionary studies, the emphasis on forests as the potential and most important vegetation, and the difficulties many researchers have accepting the ecological and evolutionary role of disturbances at broad scales, suggest that we are still largely viewing nature through the eyes of Humboldt.

After reading the book, I was lucky enough to be in London for a conference and met William Bond in a pub just next to Kew Gardens. We stayed hours talking about many things, mainly fire, grazing, alternative stable states, and all the wonders of ecosystems maintained by disturbances. Our conversation jumped from one country to the other, from one biome to the other, and from one continent to another. And when talking about the overwhelming role that many researchers attribute to the environment when explaining broad temporal and spatial vegetation patterns [2], we glimpsed the long shadow of Humboldt. That conversation in a quiet London pub was the seed of this paper (and of another to come). Talking with William is always enjoyable because of his enthusiasm, experience, and creativity.

Now that we are approaching the 250th anniversary of Humboldt’s birth, it is instructive to evaluate his legacy of climate and soil as primary factors explaining broad vegetation patterns. There is increasing evidence that many open, non-forested ecosystems (savannas, grasslands, and shrublands) cannot be predicted by climate and soil – and are ancient and diverse systems maintained by fire and/or vertebrate herbivory. Paleoecological and phylogenetic studies have shown the key role of fire and grazing at geological time scales (Fig. 2). In this paper [1], we propose moving beyond the legacy of Humboldt by embracing fire and large mammal herbivory as key factors in explaining the ecology and evolution of world vegetation. This implies understanding grasslands, savannas, and shrublands as ancient and diverse ecosystems that require conservation, including the processes that maintain them (grazing and wildfires).
 

Fig. 2. Changes of the drivers related to plant consumers (fire and herbivory), together with the evolution of different vegetation types, and some plant traits (serotiny and thick bark of pines, epicormic resprouting in eucalypts), along the evolutionary history of plants. Upper pointing triangles are peaks of O2 atmospheric concentration and fire activity; lower-pointing triangles are megafauna extinction events, also associated to fire activity peaks. Note that modern fire regimes are very recent, and at this scale they are almost a point. From [1].

Fig. 3. Alexander von Humboldt and Aimé Bonpland on the foot of Chimborazo, painting by Friedrich Georg Weitsch (1810)

 
References
[1] Pausas J.G. & Bond W.J. 2019. Humboldt and the reinvention of nature. J. Ecol. [doi | jecolblog | pdf]

[2] Pausas J.G. & Lamont B.B. 2018. Ecology and biogeography in 3D: the case of the Australian Proteaceae J. Biogeogr. 45: 1469-1477. [doi | pdf]
 

Doñana postfire – Doñana posincendio

April 2nd, 2018 No comments

[English version]

Last summer, between Jun 24 and Jul 4 (2017), a wildfire burned ca. 10,000 ha of the Doñana Natural Park (Las Peñuelas fire, Moguer, Huelva, Spain); the fire did not affect the adjacent Doñana National Park (National P. + Natural P. = 108,000 ha). Most of the area burned was a shrubland in a fixed dune system that had been afforested with Pinus pinea during the early 20th C. Now, nine months after fire, there are many plants from the original shrubland that are resprouting and many seeds germinating (pictures below); most of the pines are dead with very poor or null regeneration, so part of the afforestation (which is much larger than this fire) is lost.

From the ecological point of view, this fire provides an opportunity to replace part of the afforestation with the natural shrubland, and thus the wildfire may help to restore the original ecosystems and their biodiversity. This ecosystem will also benefit from having more water available, as tree consume a lot of water. In addition, future fires occurring in the shrubland without the tree layer would be also less intense. Consequently, the regenerating shrubland will be more natural and more resilient to future fires than the prefire pine woodland.

 

[Versión en español]

El verano pasado, entre el 24 de junio y el 4 de julio (2017), un incendio afectó ca. 10.000 ha del Parque Natural de Doñana (incendio de Las Peñuelas, Moguer, Huelva, España); el fuego no afectó al Parque Nacional de Doñana adyacente al parque natural (P. Nacional + P. Natural = 108.000 ha). La mayor parte del área quemada era un matorral en un sistema de dunas fijas en el que se había plantado pinos (Pinus pinea) a principios del siglo XX. Ahora, nueve meses después del incendio, hay muchas plantas del matorral original que están rebrotando y muchas semillas germinando (ver fotos); la mayoría de los pinos están muertos y presentan una regeneración muy pobre o nula, por lo que una parte de la repoblación de pinos (que era mucho más grande que este incendio) ha desaparecido.

Desde el punto de vista ecológico, este incendio brinda la oportunidad de reemplazar la repoblación por el matorral natural y, por lo tanto, el incendio pueden ayudar a restaurar los ecosistemas originales y diversos de Doñana. Estos ecosistemas también se beneficiarán de una mayor disponibilidad de agua, ya que hasta ahora una parte era consumida por los pinos. Además, los incendios futuros que ocurran en estos matorrales sin pinos serán menos intensos. En consecuencia, el matorral en regeneración será más natural y más resiliente a los incendios futuros que el pinar anterior.

UPDATE (Jan 2019): this post has inspired the following article:

Leverkus AB, Murillo PG, Doña VJ, Pausas JG. 2019. Wildfires: opportunity for restoration? Science 363 (6423): 134-135. [doi | science | pdf]

 

Conservation of cork oak ecosystems

March 14th, 2011 No comments

Mediterranean cork oak (Quercus suber) savannas, which are found only in southwestern Europe and northwestern Africa, are ecosystems of high socioeconomic and conservation value. Characterized by sparse tree cover and a diversity of understory vegetation, these ecosystems require active management and use by humans to ensure their continued existence. The most important product of these savannas is cork, a non-timber forest product that is periodically harvested without requiring tree felling. Market devaluation of, and lower demand for, cork are causing a decline in management, or even abandonment of cork oak savannas. Subsequent shrub encroachment into the savanna’s grassland components reduces biodiversity and degrades the services provided by these ecosystems. In contrast, poverty-driven overuse is degrading cork oak savannas in northwestern Africa. “Payment for ecosystem services” schemes, such as Forest Stewardship Council (FSC) certification or Reducing Emissions from Deforestation and Degradation and enhancement of carbon stocks (REDD+) programs, could produce novel economic incentives to promote sustainable use and conservation of Mediterranean cork oak savanna ecosystems in both Europe and Africa.

Bugalho M.N., Caldeira M.C., Pereira J.S., Aronson J., & Pausas J.G. 2011. Human-shaped Cork oak savannas require human use to sustain biodiversity and ecosystem services. Frontiers in Ecology and the Environment 9: 278-286 [doi | pdf] [featured on the cover: pdffoto]  podcast

Aronson J., Pereira J.S., Pausas J.G. (eds). 2009. Cork Oak Woodlands on the Edge: conservation, adaptive management, and restoration. Island Press, Washington DC. 315 pp. [the book]

More posts on oaks.

Foto: D. Crespo (Portugal)

Fire and alien plants

November 25th, 2010 No comments

In Mediterranean Basin ecosystems, fires are frequent, and post-fire regeneration is tipically based on native species, that is, there is no invasion of alien species after fire. However, this is not the case in the other Mediterranean climatic regions, where fire frequencies higher than their natural (historic) fire regime favors the invasion of alien plants. This is specially the case in the Mediterranean ecosystems of Chile, where recurrent fires play a little role on the evolutionary history. In Chile, fires appeared with the indigenous settlements, and increased exponentially since the time of the Spanish invasion (1536). This increase in fires, together with heavy grazing, has reduced the native matorral and increased the invasive species. In a recent paper, Gómez-Gonzalez et al. [1] show that fire open the window for the establishment of annual plants, and most of them are alien (from the Mediterranean Basin). The successful establishment of alien annuals was due to their ability to maintain rich seedbanks in burned areas and to the greater propagule arrival compared to native species (annuals or perennials). Thus the results demonstrate that fire is a relevant factor for the maintenance of alien-dominated grasslands in the Chilean matorral and highlight the importance of considering the interactive effect of seed rain and seedbank survival to understand plant invasions patterns in fire-prone ecosystems.

[1] Gómez-González S, Torres-Díaz C., Valencia G, Torres-Morales P, Cavieres L.A., and Pausas J.G (in press). Anthropogenic fires increase alien and native annual species in the Chilean coastal matorral. Diversity and Distributions 17: 58-67 [doi | pdf]

invasion-fumaria_sm
Figure: Chilean matorral recently burnt showing the invasion of Fumaria capreolata (flowering), and annual alien species original from Europe (Foto by S. Gómez-González).

Wine supporting biodiversity

January 5th, 2010 No comments

Good news: Sainsbury’s to pop new corks for wildlife. All of Sainsbury’s own-brand wines will be sealed with corks certified by the Forest Stewardship Council by the end of 2010 [see The Guardian, 31/Dec/2009].  Sainsbury is the third largest chain of supermarkets in the United Kingdom. We hope other supermarkets and wine makers will follow this initiative.

Remeber that IUCN proposed ten things we all can do to save biodiversity [see], and one was to only drink wines with natural cork stoppers!

Cork oak (Quercus suber) is a WWF priority species, because it is one of the most ecologically, economically and/or culturally important species.

For more information on cork oak woodlands see the book Cork Oak Woodlands on the Edge, and the WWF Cork Oak Programme.

cover_old2

corcho_WWF treebark1sm

Amazonia: The empty forest

October 27th, 2009 No comments

We all now about the over-exploitation and over-hunting in many ecosystems, including the Amazonian forests. Recently, travelling in Brazil I found some figures on the magnitude of the hunting in the Amazon, they are unbelievable:

Number of animals legally exported from one single port (Iquitos, a river port in the Peruvian Amazon) during 5 years (1962-1967):

183,664 – Monkeys
149,256 – Caiman species (Melanosuchus and Caiman)
67,575 – Capybaras (Hydrochaeris)
47,851 – Otter (Lutra)
2,529 – Giant otter (Pteronura)
61,499 – Ocelots (Leopardus pardalis = Felis pardalis)
9,565 – Margay (Leopardus wiedii = Felis wiedii)
5,345 – Jaguar (Panthera onca)
690,210 – Collared Peccary (Pecari tajacu = Tayassu tajacu)
239,472 – White-lipped Peccary, Tayassu pecari,
239,470 – Deer (Mazama)

Total > 1.6 millions of animals!

But, you need to add those that were hunted for local consumption (estimated to be as many as to those hunted for legally exporting, above), and those hunted illegally (estimated to be much more that those hunted legally). And this is only for one single port, for a only 5 years, and only for large mammals and caimans … (birds, turtles, lizards, etc… are also hunted). This strong defaunation of vertebrates has implication not only on animal biodiversity but it has also cascading effects on ecosystems (e.g., reducing predation, herbivory, dispersal of plants, etc.). [more info: R. Dirzo]

The Amazon is now a great place for any biologist, how would it be if it was not an empty forest!

Amazon_Manaus_RioNegro-RioSolimoes
MISR image of the Central Amazon showing the city of Manaus, the meeting-of-the-waters where the Rio Negro and Rio Solimoes merge.

Sources:
Fenandéz, F. 2009. O poema imperfeito, 2on ed., UFPR editora.
Redford, K.H. 1992. The empty forest. BioScience, 42(6), 412–422.

Biodiversity and wine

October 22nd, 2009 No comments
IUCN propose ten things we all can do to save biodiversity [see], and one is to only drink wines with natural cork stoppers!

Cork stoppers do not pollute the environment (as opposite to plastic stoppers), but also their use save the Cork oak woodlands. These forests face a major threat: the growing use of plastic and metal substitutes for cork stoppers in wine bottles, cork’s main market. If the economic value of cork oak forests is not maintained cork oaks will be cleared for other land uses.

Cork oak (Quercus suber) is a WWF priority species, because it is one of the most ecologically, economically and/or culturally important species.

WWF cork oak programme

For more information on cork oak woodlands see the book Cork Oak Woodlands on the Edge, and the WWF Cork Oak Programme.

Ground fires in Tablas de Daimiel Nat Park

October 21st, 2009 No comments

Ground (peat) fires are rare in the Mediterranean basin, but here is an example, in a wetland that burns because drained for agricultural purposes. Overexploitation of water resources (illegal wells and canalisation of the rivers) has caused the water-table to drop, and made prone to burn. This is happening in a National Park classified as a UNESCO biosphere site and an EU protected area because of its birdlife …

  • Spanish wetlands shrouded in smoke as overfarming dries out peat, Guardian.co.uk, 19 Oct 2009
  • EU Investigates Dried Up Spanish Wetland, Fox News (Ass. Press), 22 Oct 2009
  • Spanish wetland facing destruction as farming starves it of water, Guardian.co.uk, 22 Oct 2009
  • More news

News in Spanish | Noticias:

  • Un insólito incendio subterráneo azota las Tablas de Daimiel, El País, 12 Oct 2009
  • Medio Ambiente admite que el daño en las Tablas ‘es irreversible’, El País, 13 Oct 2009
  • Trasvase de emergencia contra el incendio subterráneo de Daimiel, El País, 14 Oct 2009
  • El parque nacional de Las Tablas de Daimiel agoniza, LaVanguardia.es, 18 Oct 2009
  • Hallado otro foco del fuego subterráneo de Daimiel, El Pais, 20 Oct 2009
  • Cuatro fuegos bajo Daimiel, El Pais, 31 Oct 2009
  • Greenpeace augura un “futuro agónico” a Las Tablas de Daimiel, Europa press, 7 Nov 2009
  • Salvemos las Tablas de Daimiel, CLM en Vivo [video]
  • Ecologistas rechazan el tasvase a Daimiel [video]
  • Más noticias.
  • Información previa sobre el estado del Parque, en El País, 1 Jun 2008

Tablas de Daimiel National Park: [wikipedia-EN | wikipedia-ES |  video ].

When talking about peat fires we remember the 1997 Indonesia fire which burned 8 million hectares and countless millions of people suffered from air pollution (see figure below). In that area there was abundant and thick peat (which is a very important carbon store) that was drained for land development and agriculture (e.g., palm oil production), making them prone to fire. As a consequence of burning this dry peat, the 1997 Indonesia fire emitted a vast amount of carbon dioxide to the atmosphere. Indeed, the growth rate of carbon dioxide in the atmosphere doubled and reached the highest levels on record; it was equivalent to 13-40% of the mean annual global carbon emissions from fossil fuels yet it came from a small area of the globe (Page et al. 2002).

2007_indonesia_fires_smog3
Air pollution over Indonesia and the Indian Ocean on October 22, 1997 (TOMS satellite instrument)

Certainly we need to preserve wetlands and peatlands, not only for their biodiversity value, but also for their role in the global carbon budget.