Over a decade ago, Leo Breiman (2001a) wrote: “There are two cultures in the use
of statistical modeling to reach conclusions from data. One assumes that the data
are generated by a given stochastic data model. The other uses algorithmic models
and treats the data mechanism as unknown. The statistical community has been
committed to the almost exclusive use of data models. This commitment has led to
irrelevant theory, questionable conclusions, and has kept statisticians from working
on a large range of interesting current problems. Algorithmic modeling, both in
theory and practice, has developed rapidly in fields outside statistics.”
Climate change is negatively affecting tropical regions through increasing temperatures and decreased precipitation leading to changes in local hydrology and decreasing water supply among others. In order to make accurate future predictions of carbon stock and forest health it is necessary to better understand the current underlying baseline carbon stock and how it may vary across space. Here we adapted an existing carbon stock assessment method and applied it to two tropical regions in Nicaragua and Costa Rica managed by the Maderas Rainforest Conservancy. Carbon stock was calculated based on 1) above-ground tree biomass, 2) above-ground sapling biomass, 3) leaf litter, herb and grass biomass, 4) soil organic carbon, 5) below-ground biomass, 6) stumps and deadwood and 7) regenerating plants. Our results show a strata-pooled average of 234.09 ± 379 Mg C ha-1 (n=40) carbon at the Costa Rican site and 209.20 ± 216 Mg C ha-1 (n=40) at the Nicaraguan site. These values are much higher than those available on a biome-wide scale, highlighting the extent of carbon stock loss outside these study areas as a result of anthropogenic disturbances, in comparison to more pristine areas. Local investigations into carbon stocks in the tropics are necessary to better estimate the current state of carbon content in the tropics. By adapting existing sampling protocols to local conditions this can be achieved efficiently. Furthermore, local estimates of carbon stock enable non-governmental organizations (NGOs) to participate in the Reducing Emissions from Deforestation and forest Degradation (REDD) program led by the United Nations.
The tropics eternally fascinate us. But tropical land- and seascapes mean many
things for many people (Forsyth and Miyata 1987; Kricher and Plotkin 1999). For
some, they can be a great home, a wonderful holiday, and a study site, while for
others they constitute a miserable life (with an average daily income of US$ 4) in a
life-threatening habitat (Collier 2007; Davis 2007). It is not an overstatement to say
that in the tropics, one can die easily. To the rest of the world, however, the tropics
still represent a land of opportunity (a “lebensraum”; Figs. 1.2 and 1.3)…..
Abstract of the feasibility study:
The research described in this feasibility report indicates that The Ocean Cleanup Array is a feasible and viable method to remove large amounts of plastic pollution from a major accumulation zone known as the Great Pacific Garbage Patch. Computer simulations have shown that floating barriers are suitable to capture and concentrate floating plastic debris. Combined with ocean current models to determine how much plastic would encounter the structure, a cleanup efficiency of 42% of all plastic within the North Pacific gyre can be achieved in ten years using a 100 km Array. In collaboration with offshore experts, it has been determined that this Array can be made and installed using current materials and technologies. The estimated costs are €317 million in total, or €31.7 million per year when depreciated over ten years, which translates to €4.53 per kilogram of collected ocean debris.
One of the powerful figures in the article. Here we see figure 4 a which shows predicted change from 2010 to 2100 based on future CanESM 2 data. The values shown here are mean predicted relative occurrence indeces (ROI) pooled over all 38 species that were modeled out. Warm colours show high predicted change and cool colours show lower change. The general trends of our study indicate a decline in ROI predictions for 2100. We think this represents an indication for a declining habitat quality and decreasing distribution range for traditional Antarctica species. One can see that eastern Antarctic waters are predicted to be among the most affected regions of change.