5 research outputs found
Protecting tropical forests from the rapid expansion of rubber using carbon payments
Expansion of Hevea brasiliensis rubber plantations is a resurgent driver of deforestation, carbon emissions, and biodiversity loss in Southeast Asia. Southeast Asian rubber extent is massive, equivalent to 67% of oil palm, with rapid further expansion predicted. Results-based carbon finance could dis-incentivise forest conversion to rubber, but efficacy will be limited unless payments match, or at least approach, the costs of avoided deforestation. These include opportunity costs (timber and rubber profits), plus carbon finance scheme setup (transaction) and implementation costs. Using comprehensive Cambodian forest data, exploring scenarios of selective logging and conversion, and assuming land-use choice is based on net present value, we find that carbon prices of 51 per tCO2are needed to break even against costs, higher than those currently paid on carbon markets or through carbon funds. To defend forests from rubber, either carbon prices must be increased, or other strategies are needed, such as corporate zero-deforestation pledges, and governmental regulation and enforcement of forest protection
Denial of long-term issues with agriculture on tropical peatlands will have devastating consequences
Lette
The role of plant functional traits in shrub distribution around alpine frost hollows
Introduction/Aims
Functional traits aid understanding of species distribution and community composition along environmental gradients. However, studies that detail trait measurements along fineāscale environmental gradients are lacking for many vulnerable ecosystems. In this paper, we quantify how plant traits might explain the composition of shrubs in one such vulnerable system ā frost hollows.
Location
Bogong High Plains, Victoria, Australia.
Methods
We measured species composition and a suite of traits (shrub height, stem specific density, leaf area and SLA, xylem vessel area and density, and leaf bud traits) for shrub species in three, 10 m Ć 10 m quadrats located across transition from hilltops down into frost hollows. We used ordinal regression to model vegetation transitions by relating the changes in shrub species occurrence along frost hollow gradients to each trait, and across multiple traits. We also assessed intraspecific trait variations along gradients.
Results
Several traits explained the position of species along a gradient of cold air accumulation (slopes leading into frost hollows). The most important traits were maximum shrub height, leaf area and xylem traits, which were clearly related to species location on the slopes in single trait models. More complex relationships were revealed with multiātrait models, which indicated that shorter species, those with smaller leaves and larger buds for their leaf size, and those with lower vessel density were more likely to be found toward the bottom of the slope. Within species, taller individuals and those with denser stems were also more common upāslope.
Conclusion
Our results suggest a shift in ecological strategies in frost hollows: the advantages of being taller and having large leaves may be diminished in these stressful environments. Shrubs that are shorter and have smaller leaves may also be better at avoiding the risk of frost damage. Our study shows how the fineāscale turnover of shrub species composition around frost hollows relates to plant functional traits, and captures the allocation tradeāoffs between coping with environmental stress and being competitive within these plant communities
School Mathematics Curricular Reform: An Asian Experience
This chapter sets the background and rationale for the book and introduces the reader to the different contributed chapters. It identifies the common features of school mathematics curricula in Asian countries and presents a birdās eye view of the recent curricular initiatives and reforms in some of these countries. The chapter also outlines some of the important lessons that can be learned from the Asian experiences and offers a direction for advancing school mathematics curricula