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Doom of the elephant-dependent trees in a Congo tropical forest

In an evergreen lowland rain forest of the Cuvette Centrale, DR Congo, at the LuiKotale Max-Planck research site, forest elephants (Loxodonta cyclotis) are close to extinction. Between January 2009 and June 2011 we investigated the influence of elephant decline on sustainability of elephant-dispersed tree populations.For this, we explored how trees with the megafaunal syndrome reproduce [...]

Soil Nitrogen Will Limit Future Carbon Uptake By Plants

Increased concentrations of carbon dioxide in the atmosphere support greater plant biomass in grasslands, but this response is constrained in the long term by soil nitrogen availability. doi: http://dx.doi.org/10.1038/nclimate1841

Recent declines of Populus tremuloides in North America linked to climate

Populus tremuloides (trembling aspen) recently experienced extensive crown thinning, branch dieback, and mortality across North America. To investigate the role of climate, we developed a range-wide bioclimate model that characterizes climatic factors controlling distribution of aspen. We also examined indices of moisture stress, insect defoliation and other factors as potential causes of the decline. Historic [...]

Global assessment of the effects of terrestrial acidification on plant species richness

This study estimates the potential losses of vascular plant species richness due to terrestrial acidification for different world’s biomes. We used empirical occurrence data of 2409 species from 140 studies and estimated the relative species richness – pH response curves using logistic regressions. The regressions were then used to quantify the fraction of species that [...]

Brominated and Chlorinated Flame Retardants in Tree Bark from Around the Globe

Brominated and chlorinated flame retardants were measured in about 40 samples of tree bark from 12 locations around the globe. The analytes were polybrominated diphenyl ethers (PBDE), Dechlorane Plus (DP), decabromodiphenylethane (DBDPE), hexabromocyclododecane (HBCD), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), pentabromobenzene (PBBz), and tetrabromo-p-xylene (pTBX). The highest concentrations of these compounds were detected at an urban site [...]

Are we approaching ‘peak timber’ in the tropics?

Over the past few decades, tropical timber production in many Asia–Pacific countries has been akin to the symmetric logistic distribution curve, or ‘Hubbert Curve’, observed in the exploitation of many non-renewable resources—a rapid increase in production followed by a peak and then decline. There are three principal reasons why logging of native tropical forests resembles [...]

Mercury Distribution across 14 U.S. Forests. Part II: Patterns of Methyl Mercury Concentrations and Areal Mass of Total and Methyl Mercury

This study characterized distribution patterns of monomethyl mercury (MeHg) and areal mass of total mercury (THg) and MeHg across U.S. upland forests. MeHg concentrations increased from surface litter (average: 0.14 μg kg–1) to intermediate (0.47 μg kg–1) and deeper, decomposed litter (1.43 μg kg–1). MeHg concentrations were lower in soils (0.10 μg kg–1 at 0–20 [...]

Ash Tree Killing Insect Now East of the Hudson

The discovery of emerald ash borer (EAB) in Dutchess County, directly across the Hudson River from a large infestation found two years ago in the City of Kingston and its vicinity, has been confirmed by the U.S. Department of Agriculture’s Animal Plant Health Inspection Service (APHIS). This marks the first discovery of EAB east of [...]

Long-term perspective on wildfires in the western USA

Understanding the causes and consequences of wildfires in forests of the western United States requires integrated information about fire, climate changes, and human activity on multiple temporal scales. We use sedimentary charcoal accumulation rates to construct long-term variations in fire during the past 3,000 y in the American West and compare this record to independent [...]

Limitations to sustainable frankincense production: blocked regeneration, high adult mortality and declining populations

5. Under the ‘business as usual’ scenario, population models projected a 90% decline in the size of tapped and untapped populations within 50 years and a 50% decline in frankincense yield within 15 years. Model simulations for restoration scenarios revealed that populations and frankincense production could only be sustained with intensive management leading to full sapling [...]