Patterns of wood carbon dioxide efflux across a 2,000-m elevation transect in an Andean moist forest

During a 1-year measurement period, we recorded the CO2 efflux from stems (RS) and coarse woody roots (RR) of 13–20 common tree species at three study sites at 1,050, 1,890 and 3,050 m a.s.l. in an Andean moist forest. The objective of this work was to study elevation changes of woody tissue CO2 efflux and the relationship to climate variation, site characteristics and growth. Furthermore, we aim to provide insights into important respiration–productivity relationships of a little studied tropical vegetation type. We expected RS and RR to vary with dry and humid season conditions. We further expected RS to vary more than RR due to a more stable soil than air temperature regime. Seasonal variation in woody tissue CO2 efflux was indeed mainly attributable to stems. At the same time, temperature played only a small role in triggering variations in RS. At stand level, the ratio of C release (g C m−2 ground area year−1) between stems and roots varied from 4:1 at 1,050 m to 1:1 at 3,050 m, indicating the increasing prevalence of root activity at high elevations. The fraction of growth respiration from total respiration varied between 10 (3,050 m) and 14% (1,050 m) for stems and between 5 (1,050 m) and 30% (3,050 m) for roots. Our results show that respiratory activity and hence productivity is not driven by low temperatures towards higher elevations in this tropical montane forest. We suggest that future studies should examine the limitation of carbohydrate supply from leaves as a driver for the changes in respiratory activity with elevation

The missing pillar : Eudemonic values in the justification of nature conservation

The public justification for nature conservation currently rests on two pillars: hedonic (instrumental) values, and moral values. Yet, these representations appear to do little motivational work in practice; biodiversity continues to decline, and biodiversity policies face a wide implementation gap. In seven EU countries, we studied why people act for nature beyond professional obligations. We explore the motivations of 105 committed actors for nature in detail using life-history interviews, and trace these back to their childhood. Results show that the key concept for understanding committed action for nature is meaningfulness. People act for nature because nature is meaningful to them, connected to a life that makes sense and a difference in the world. These eudemonic values (expressing the meaningful life) constitute a crucial third pillar in the justification of nature conservation. Important policy implications are explored, e.g. with respect to public discourse and the encounter with nature in childhood