Estimating undiscovered extinctions

Have you ever wondered how many species were lost before we had the chance to discover them? In a paper now out in Conservation Biology, we estimated just that, for plant species in Singapore. This paper follows from the Chisholm Lab’s related work on Singapore birds and butterflies. All over the world, many species remain undiscovered while both known and unknown species continue to go … Continue reading Estimating undiscovered extinctions

Boolean qualitative modelling on Christmas Island

Conservation managers often want us to predict how species will respond to different management options when we don’t have enough data to parameterise a dynamical model. Previously, we found that a popular Qualitative Modelling technique involving probabilistic analysis has philosophical problems and produces contradictory results. We proposed a new method, based on Boolean analysis, that remedied these problems (Kristensen et al. 2019 Meth Ecol Evol). … Continue reading Boolean qualitative modelling on Christmas Island

Extended Tea Bag Index to measure microbial- and termite-driven decomposition in the tropics

Our new paper about using the Tea Bag Index in the tropics, headed by Aloysius Teo, has just come out in Pedobiologia. The Tea Bag Index (TBI) was designed by Keuskamp et al. (2013) as a standardised and cheap method to quantify microbial-driven decomposition by measuring the mass loss of tea within tea bags. It can be used by scientists and citizen-scientists alike. However, we … Continue reading Extended Tea Bag Index to measure microbial- and termite-driven decomposition in the tropics

Extinction of undiscovered butterflies + tutorial

Meryl Theng just had a new paper published in Biological Conservation, where she estimated that 46% of Singapore’s butterfly species have been extirpated since 1854. The special thing about this estimate is that it includes all species that existed, including species that went extinct before we had a chance to discover them. The trick to estimating undiscovered extinctions is the SEUX model. There is a … Continue reading Extinction of undiscovered butterflies + tutorial

Boolean approach to qualitative network modelling

In a new paper in Methods in Ecology and Evolution (draft with supplementary here), we tackled an important question for ecological modellers: how do we predict an ecosystem’s behaviour when the data needed to parameterise a model are lacking? This problem is particularly important when our models are needed for conservation decision-making. For example, managers may be considering different pest-control programmes, which have the potential … Continue reading Boolean approach to qualitative network modelling

Why does it matter to conservation decision-making if alternative Qualitative Modelling methods produce contradictory predictions?

Previously, I have written about how the probabilistic approach to Qualitative Modelling (QM) (e.g. Raymond et al. 2011) can lead to contradictory predictions of species response to a management intervention, and how this is similar to the paradoxes of the Principle of Indifference that we find in the philosophy literature. A reviewer of our new manuscript (Kristensen et al. 2019) asked us an interesting and … Continue reading Why does it matter to conservation decision-making if alternative Qualitative Modelling methods produce contradictory predictions?

Relationship between species discovery and extinction probability

What is the relationship between a plant’s historical probability of having being discovered and its probability that it went extinct? All else being equal, species with low abundance are less likely to be collected, and low abundance is both theoretically (e.g. McCarthy et al., 2014) and empirically cited as a good predictor of extinction probability. The empirical relationship has been observed both in general (McKinney, … Continue reading Relationship between species discovery and extinction probability

Moments for a bivariate beta distribution

A common choice for a probability distribution of a probability is the beta distribution. It has the required support between 0 and 1, and with its two parameters we can obtain a pretty wide qualitative range for the probability density function. What should we do if we want to create correlated probabilities? We might look for some kind of multivariate generalisation of the beta distribution, … Continue reading Moments for a bivariate beta distribution