Religando a rede da vida: Reconexões de interações e a robustez de redes ecológicas


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Perda de espécies e efeitos em cascata

Scale-throated Hermit (Phaethornis eurynome). ©Pedro Lorenzo.

Rabo-branco-de-garganta-rajada (Phaethornis eurynome). ©Pedro Lorenzo.

Minimizar os efeitos do atual processo de extinção em massa do Antropoceno se tornou um dos principais desafios da nossa era. Os dados sugerem que a taxa atual de perda de espécies é 100-1.000 vezes maior do que as taxas de fundo observadas no registro geológico. “Mas realmente importa se uma espécie é perdida?” Essa questão que permeia os debates sociais e políticos, geralmente para desqualificar os esforços de conservação, também tem intrigado os cientistas da conservação.

Sabemos que as espécies não ocorrem sozinhas em seu ambiente. Elas estão  interligadas por suas interações ecológicas, formando redes complexas. Nessas redes, a perda de uma espécie pode resultar em um efeito dominó, culminando na perda secundária de outras espécies. Esse processo é conhecido como co-extinção. As estimativas da magnitude das taxas de extinção passadas e futuras muitas vezes falharam em explicar a interdependência entre as espécies e as conseqüências da perda primaria de espécies. Continue reading

What method has transformed your field the most, during your career?

In the 4th and final installment of Barb Anderson’s INTECOL 2013 podcasts, she asks a number of delegates: What method has transformed your field the most, during your career?

The answers in this podcast are given by the following people:

  1. Steve Hubbell, University of California, Los Angeles, USA (00.21)
  2. Georgina Mace, University College London, UK (00.44)
  3. Carsten Dormann, University of Freiburg, Germany (01.07)
  4. Continue reading

What are the newest methods being used?

At INTECOL 2013, Methods’ Associate Editor, Barb Anderson, interviewed a number of delegates and asked them: What is the newest method that you currently use?

The answers in this podcast are given by the following people:

  1. Bill Sutherland, University of Cambridge, UK (00.18)
  2. Georgina Mace, University College London, UK (01.04)
  3. Simon Leather, Harper Adams University, UK (01.12) Continue reading

What are the oldest methods still being used?

At INTECOL 2013, Methods’ Associate Editor, Barb Anderson, asked a number of delegates: “What is the oldest method that you still use today?” This podcast includes the answers given by the list of people below.

Barb also produced podcasts about the newest methods currently being used, potentially useful methods that have not yet been invented, and the most transformational methods in various fields of research.

  1. Chris Thomas, University of York, UK (00.40)
  2. Sue Hartley, University of York, UK (00.46)
  3. Ken Wilson, Lancaster University, UK (00.53) Continue reading

Methods Digest, October 2009

Here is a round-up of some interesting methods papers published in the past few weeks. If you see any more papers that you would like to see flagged up, leave a comment below or email me.

In PLoS Biology Wayne Getz presents a thoughtful review of the models and modelling approaches that might be useful in predicting the consequences of multiple threats to ecosystems from a food web / ecosystem perspective.

Ecology has several interesting methods papers: Murray Efford and colleagues show how it is possible to use likelihood methods to estimate densities of animals from arrays of passive detectors (such as arrays of microphones). Michael Neubert et al. present a new method for estimating the rate of growth of perturbations in transient dynamics. Jessica Metcalf et al. apply integral projection models to the problem of estimating flux of individuals in tropical forests. And Grosbois et al. demonstrate a new approach for estimating individual survival / mortality rates from mult-population data.

In Conservation Biology Berlund et al. show how Bayesian methods can be used to understand habitat association of trees from presence records and environmental data. Finn et al. compare methods for estimating population size variability with a view to priortising populations that are more risk to extinction from variability. And Christopher Grouios & Lisa Manne ask whether occupancy or abundance data are more useful in predicting population persistence and how this impacts on reserve design.

Ecology Letters has a paper by Paul Murtaugh comparing model selection methods that is likely to be of general interest. Mosser et al argue that density may not be a generally good measure of habitat quality (in terms of food/ resources), particularly if low quality habitat provides a refuge for non-reproductive  individuals.

Finally, in Systematic Biology Sennblad & Lagergren show how probabilistic orthology analysis can be used to overcome some of the problems in identifying orthologous genes and gene products. And there is some debate about the use of barcodes in taxonomy centring on the effects of sampling error on the model used to delimit species.

INTECOL09 – a ‘model’ meeting

For like someone like myself, interested and enthused by ecological models, this INTECOL meeting has been incredibly pleasing. The number of talks about models, and particularly the application of models to real-world applied problems, has been genuinely impressive. Here I just want to highlight a few of the key themes from the modelling sessions at INTECOL.

Adaptive management (basically and iterative approach using the lessons from previous /current management to improve decision making) is one ‘hot’ topic. Brendon Wintle in his talk “adaptive management needs beautiful models” made a convincing case for the role of modeling in implementing this, and this seems to be a growing and successful area with plenty of examples of this being done.

The theme of the meeting is climate change – and there has been no dearth of models for predicting the effects of climate change. My colleague Mark Ooi has been keeping an eye on this area and its development over recent years, he commented:

A methodological leap forward highlighted during this conference has been the concerted shift from predictions made in the past based on bioclimatic-habitat models, to new approaches incorporating ecological processes and mechanistic responses of biota to climate change.

This shift is an understandable progression, considering the complex nature of the impacts that climate change will have, and the factors incorporated have included demographic, physiological, genetic and abiotic.

However, as seems to have been the messages from several conferences past, there is still a lack of such mechanistic data available. The development and rapid dissemination of these emerging methods is important, both to pre-empt the wave of climate change response data due to roll in, better predict global change scenarios and to provide a platform for the development of effective conservation strategies.

There was a really interesting session yesterday on modelling, and in the opening talk there was a terrific quote from Prof Hugh Possingham:

“If you don’t know what a differential equation is you are not a scientist”

His talk was on prioritizing protection versus restoration. He explained how an elegantly simple model could be used to predict how finances should be directed to minimize the loss of species via the extinction debt. A great example of a simple model combined with some basic ecological knowledge (the species area relationship).

So for anyone interested in models, methods and applications to real-world problems, this has been an incredibly interesting meeting so far.