Archive for Ecology
The pantomime season is approaching fast, and seemingly kicked off with this piece on the BBC’s Countryfile programme last Sunday, in which Tom Heap explored the intriguing question of “why burning trees is better for the environment than many think”.
Subsequent media coverage has quoted the support of a number of conservation bodies, including ourselves, for the Forestry Commission’s desire to harvest two million tonnes of woodfuel a year from the UK’s “undermanaged” woods. Our supporters would rightly question why a woodland conservation charity like the Woodland Trust would wish to see trees felled and burned to produce heat. Read the rest of this entry »
While much of the alarm over global deforestation centres on the Amazon rainforest, which continues at a shocking rate, African rainforests receive relatively little attention. Yet a study published today in Nature demonstrates the increasing size of the carbon sink these forests contain: similar to Amazonian forests in per unit area terms.
A large international team of scientists, headed up by Simon Lewis at the University of Leeds, found that across 79 plots in ten African countries, the above-ground carbon storage increased by 0.63 Mg C per hectare per year, between 1968 and 2007. Scaling up to include unmeasured material — roots, small trees, rotting trees and so on — brings the continental increase in carbon storage to 0.34 Pg C (that’s 340 million tonnes of carbon) per year. Read the rest of this entry »
Old growth forest on the western United States is dying back at an increasing rate, accoring to a study published this week in Science magazine. The study, led by USGS biologist Phil van Mantgem, found that background mortality rates — those not directly attributable to some catastrophic effect, such as fire — have risen rapidly in recent decades.
The study, which used census data from 67 long-term plots located in ancient forests (average age 450 years, some sites in excess of 1000 years), found that mortality rates had increased at the vast majority of sites, whereas recruitment rates — replacement of dead trees with new ones — had neither increased or decreased over the same period.
The dieback couldn’t be pinned down to any local effects, such as pollution, local competition or fire prevention measures. Instead, say the study’s authors, regional warming and the ensuing water problems it brings — faster snowmelt leading to longer summer drought — are putting the strain on the trees. Read the rest of this entry »
Aren’t trees amazing? From the tiniest seed they can grow into the largest of living things, bestowing a wealth of benefits upon the wildlife that clambers, crawls, flits and buzzes among their branches. Trees provide food and shelter, regulate and cleanse water supplies. They offer protection against soil erosion and the worst impacts of wind and tides. They even create wonderlands for us to visit.
All this they do using the barest minimum of raw materials. Sunlight drives photosynthesis, the process by which the sugars that fuel growth are created. And as a tree grows it locks up tonnes of carbon – the stuff we have been blasting into the atmosphere in increasing quantities ever since we first discovered how to dig coal and suck oil out of the ground. Read the rest of this entry »