I’ve recently been working on a qualitative modelling project where I am trying to uncover “truths” about the response of species in an ecosystem to control of invasive species. Long story short, I’ve been looking into various boolean minimisation techniques. I’ve been playing with Python EDA, a Python library that I think provides a front-end to the Robert Brayton and Richard Rudell espresso heuristic logic … Continue reading “ValueError: expected a DNF expression” when trying espresso_exprs example from pyeda docs
(Update April 2019: a paper on the topic below has now been published in MEE) Qualitative modelling Qualitative modelling (QM) holds the promise of obtaining predictions from dynamical models even when we don’t have all the data needed to parameterise them. How does QM achieve this? In short, the idea is to explore the range of possible parameter values to create an ensemble of possible … Continue reading The Principle of Indifference in ecological modelling
This is a brief summary of a debate about the relationship between biodiversity conservation (BD) and managing for ecosystem services (ES) and the proper role of conservation. The debate centers around an article by Kareiva and Marvier (2012) and the discussion that followed. Some threads of the discussion were: A reply by Soule (2013), followed by Marvier (2014), and those below. A reply by Miller … Continue reading Biodiversity versus ecosystem services
I just found a pretty early reference to the possibility of climate change leading to asynchrony between plant and animal phenology. From Chapter 10 page 295 of Climate Change: The IPCC Scientific Assessment (1990) Of crucial importance in plant community functioning is the synchronous operation of the life cycles of interacting plants, animals and soil organisms. Complex synchronies are found in communities in which the … Continue reading The IPCC First Assessment Report and phenological synchrony
Typically the the kinds of models that I’m interested in assume that fledging rate is very dependent upon a phenological match between nestlings’ peak food requirements and the peak in caterpillar abundance. However I recently read a study by Cholewa and Wesołowski (2011; Acta Ornithologica) pointing out that, while literature shows that blue tits and marsh tits are indeed strongly dependent upon this food type, … Continue reading Are caterpillars really that important?
Climate change has caused an advance in phenological events in many species. In migratory birds, the effects of warming flow causally up the trophic levels. For example, warmer temperatures lead to earlier plant phenology (e.g. budding), which leads to earlier peaks in the abundance of foods (e.g. insect larva) that are important to raising nestlings, which puts pressure upon birds to advance their own breeding … Continue reading Do birds sometimes respond to warming temperatures by delaying their phenology?
Climate change has caused an advance in phenological events in many species (Forchhammer et al. 1998, Chmielewski & Rotzer 2001, Parmesan & Yohe 2003, Edwards & Richardson 2004, Menzel et al. 2006, Beebee 2009). In migratory birds, the effects of warming flow causally up the trophic levels. For example, warmer temperatures lead to earlier plant phenology (e.g. budding) (Menzel et al. 2006, Schwartz et al. … Continue reading The problem of arrival time and prelaying period in migratory birds
McDonald-Madden (2010; TREE): Is monitoring worthwhile? The benefits of the information gained from monitoring do not always outweigh the costs of acquiring it. For example, if one’s management strategy is not dependent upon the state of the system, one does not need to monitor. Or if one is unsure about the cause of decline, it may make more sense to spend resources researching that rather … Continue reading Monitoring for conservation
One of the most memorable moments in Al Gore’s movie “An Inconvenient Truth” occurs as Gore discusses the ice-core records for CO2 and temperature over the previous 7 “ice-ages”. After graphically showing the strong correlation between CO2 and temperature in these records, Gore is forced to mount a cherry-picker in order to physically point to the height on the graph that CO2 is predicted to … Continue reading Fischer and the CO2 vs temperature lag
Roughly speaking, greenhouse gases have been continually increasing since 1900. They underwent a steady increase from 1900, with a sharp acceleration around 1950, followed by continued increase at this faster rate up until now. In contrast, global temperatures have oscillated. They showed a sharp increase from 1920, plateaued and then dropped around 1950, before picking up pace and increasing sharply again around 1970. Recently I … Continue reading Greenhouse gas vs temperature