From the Riviera to Rivierenbuurt

I have moved from the shores of the Mediterranean to the banks of the Amstel River in Amsterdam. I am now in the land of windmills, canals, clogs, and parakeets.

Parakeets? There are flock of bright green Rose-ringed parakeets (Psittacula krameri) in Amsterdam. They are noisy birds, and the story goes that one owner got so fed up with his pet parakeets that he let them fly off. Since they came from the foothills of the Himalayas, they had no problem surviving and breeding in the Netherlands.

Will the parakeets compete for resources with the local bird populations? Probably not catastrophically. Owls and goshawks now feed on them, keeping their numbers down. But they are probably here to stay.

Top 10 plants for clean indoor air

Indoor air quality is often worse that outdoor air quality. What can you do about it? Grow these plants.


Common name Scientific name Score
1 Areca palm Chrysalidocarpus lutescens 8.5
2 Lady palm Rhapis excelsa 8.5
3 Bamboo palm Chamaedorea seifrizii 8.4
4 Rubber plant Ficus robusta 8.0
5 Dracaena “Janet Craig” Dracaena deremensis “Janet Craig” 7.8
6 English ivy Hedera helix 7.8
7 Dwarf date palm Phoenix roebelinii 7.8
8 Ficus Alii Ficus macleilandii “Alii” 7.7
9 Boston fern Nephrolepis exalta “Bostoniensis” 7.5
10 Peace lily Spathiphyllum sp. 7.5

These are plants selected for their ability to remove indoor air pollution, based on research carried out for NASA’s Clean Air Study.

The score is based on four factors,

  1. Removal of chemical vapours
  2. Ease of growth and maintenance
  3. Resistance to insect infestation
  4. Transpiration rate

The information is from B.C. Wolverhampton. Eco-friendly House Plants: 50 indoor plants the purify the air in homes and offices. London: Seven Dials, 2000. For information about how to take care of the plants etc., see the book. These plants are very easy to take care of.

The Quartenary Conundrum

The Quartenary Conundrum is this: While current empirical and theoretical ecological forecasts suggest that many species could be at risk from global warming, during the recent ice ages surprisingly few species became extinct.

In a recent paper in BioScience, Forecasting the Effects of Global Warming on Biodiversity (pdf), Daniel Botkin et al. state that

Fossil evidence and recent ecological and genetic research, along with specific problems with present forecasting methods, lead us to believe that current projections of extinction rates are overestimates. Previous work has failed to adequately take into account mechanisms of persistence. […]

Until recently, it was thought that past temperature changes were no more rapid than 1 degree Celsius (°C) per millennium, but recent information from both Greenland and Antarctica, which goes back approximately 400,000 years, indicates that there have been many intervals of very rapid temperature change, as judged by shifts in oxygen isotope ratios. Some of the most dramatic changes (e.g., 7°C to 12°C within approximately 50 years; Macdougall 2006) are actually of greater amplitude than anything projected for the immediate future. […]

What, then, is the answer to the Quaternary conundrum? The answer appears to lie in part with the ability of species to survive in local “cryptic” refugia, that is, to exist in a patchy, disturbed environment whose complexity allows faster migration than forecast for a continuous landscape, within which species move only at a single rate. The answer also lies in part with greater genetic heterogeneity within species, including local adaptations,which allows rapid evolution. For example, populations close to latitudinal borders are likely to be better adapted to some environmental changes than the average genotype. However, the conundrum is not completely solved, and some important genetic research suggests that species are more vulnerable than the fossil record indicates. A fuller solution to the conundrum will be important for improving forecasts of climate change effects on biodiversity.

HT Carl Zimmer.

Note that this is not a call for complacency, it is a call for better models of climate change effects on extinctions.

Gardening is good for you

Gardening is good for you; you are physically active without doing strenuous labor, you are outdoors, you work with beautiful plants, and you can clearly see the results of your work.

Here is an additional reason why gardening might be good for you: A bacterium that lives naturally in the soil, Mycobacterium vaccae, might alleviate clinical depression.

Read here.