Oaks have a complex evolutionary history that has long eluded scientists. New research, however, provides the most detailed account to date of the evolution of oaks, recovering the 56-million-year history that has made the oaks one of the most diverse, abundant and important woody plant groups to the ecology and economy of the northern hemisphere.
A new study reveals a complex interplay between soil fungi and tree roots that could be the cause of rare-species advantage. The researchers found that the type of beneficial soil fungi living around tree roots in a subtropical forest in China determined how quickly the trees accumulated harmful, pathogenic fungi as they grew. The rate of accumulation of pathogenic fungi strongly influenced how well the trees survived when growing near trees of the same species.
Removing dead trees from the forests and reforesting on a large scale: this is the German Federal Government’s strategy against “Forest Dieback 2.0”. Scientists call for other solutions.
Before Europeans arrived in America, longleaf pine savannas sprawled across 90 million acres from present-day Florida to Texas and Virginia. Today, thanks to human impacts, less than 3 percent of that acreage remains, and what’s left exists in fragmented patches largely isolated from one another.
In the context of progressing towards new targets for a post-2020 Global Biodiversity Framework, the debate remains on whether the emphasis should be on protected area coverage or protected area effectiveness. “It is worrying that we still know so little about how effective protected areas are, especially in relation to management inputs” says Dr. Johanna Eklund from the University of Helsinki.
A recent study she led compared common indicators of Protected Area Management Effectiveness, used by for example the Global Environmental Facility, WWF and other conservation actors, to satellite-based estimates of reduced deforestation in Madagascar. The international team found that overall protected areas were reducing deforestation within their borders, although variation in effectiveness existed, highlighting also clear needs for improvements. The variation, however, was not explained by management input assessments conducted following common global protocols and widely used by funders and non-governmental organizations.
“Self-reports of management effectiveness were generally good, with rather small differences between areas. Such lack of resolution may hinder the use of management-effectiveness indicators when identifying priorities for management investments at national level” says Dr Mar Cabeza from the University of Helsinki and co-author of the new study.
Nonetheless, the results, which were recently published in the scientific journal Conservation Science and Practice, also carry some good news: approximately half of the protected areas studied showed no deforestation at all inside their borders, and only three of the areas showed very high levels of deforestation. What is more, they also showed that 29 out of the 36 studied PAs had an impact in mitigating deforestation within their borders, i.e. without protecting these areas, the situation would have been much gloomier.
“It is inspiring to be able to report that conservation actions matter”, says Dr Eklund. “Too much doom and gloom can passivate even the most enthusiastic of us; leading to despair and the feeling that both climate change and biodiversity loss are lost causes.”
Not just paper parks
Tropical forests are of utmost importance for both biodiversity and climate change mitigation, yet under increased pressures to clear land for agriculture and production. One of the most widely used policy tools currently available to avert habitat loss and deforestation is the establishment of protected areas. However, previous research has highlighted that many protected areas are so-called paper parks, i.e. established on paper but lacking active management to ensure they have the capacity to mitigate threats.
This is why it is important to investigate how protected areas perform after they have been established. Why do some protected areas seem to be effective in avoiding high pressures of logging, whereas others cannot mitigate them?
Evaluating conservation actions
To find out the impact a conservation intervention or programme has had, there is a need to evaluate the outcomes compared to what the situation would have been had the intervention not taken place. “A bit similar as in medical science”, says Dr Eklund, “where the effect of a pill or treatment is evaluated against a control group. The challenge in conservation science is that we often lack a suitable baseline to compare to; many protected areas have been established a long time ago and in areas of lower pressures, in order to avoid land conflicts in more productive landscapes. This needs to be accounted for in studies evaluating conservation effect.”
Does management matter and how?
The team compiled unique data on management inputs and how this changed over time. They had access to information on how adequate levels of personnel and funding had been, how well different monitoring and enforcement strategies had been implemented, and how the collaboration with local communities and other stakeholders had developed. Surprisingly enough though, protected areas with higher management scores did not perform better in terms of avoiding deforestation. The assessment was only able to capture an extreme case where poor management was linked to a protected area showing increased deforestation, that is, even higher levels of deforestation than predicted. The authors suggest that one explanation for the general lack of correlation may be that management levels of the PAs in Madagascar were already at basic to sound levels and located in areas with low rates of forest loss, and therefore this set of PAs provides little variation with which to explore the effect of different levels of management. Moreover, previous studies have shown that local managers identify weak governance at the national level as an obstacle for effective management, suggesting the broader sociopolitical context might matter more than local management.
Policy implications
The results have policy implications both for Madagascar and internationally. The local conservation sector in Madagascar can use the results to prioritize key areas for development and target limited conservation resources to areas where they might make the biggest difference. The results are also of relevance for the post-2020 targets of the Convention on Biological Diversity. Dr Eklund hopes that different measures of effectiveness, not merely an increase in protected area coverage, would be better incorporated into the wording of the new targets. “Continued efforts to carry out quantitative impact evaluations of protected area effectiveness, and collection of management effectiveness data, are needed, as our study shows that they can complement each other in displaying different facets of how PAs perform”, concludes Dr Eklund.
Read the paper: Conservation Science and Practice
Article source: University of Helsinky
Author: RIITTA-LEENA INKI
Image: Johanna Eklund
New findings show that old-growth forests, a critical nesting habitat for threatened northern spotted owls, are less likely to experience high-severity fire than young-growth forests during wildfires. This suggests that old-growth forest could be leveraged to provide valuable fire refuges that support forest biodiversity and buffer the extreme effects of climate change on fire regimes in the Pacific Northwest.
A recent study published in the journal Ecosphere examined the impact of the Douglas Complex and Big Windy fires that burned in the Klamath-Siskiyou region of Oregon during July 2013, a drought year. The fires burned through a long-term study area for northern spotted owls. Using information on forest vegetation before and after the fires, along with known spotted owl nesting areas, researchers had an unprecedented chance to compare the impact of wildfire on critical old-growth nesting habitat.
“On federally managed lands, spotted owl nesting habitat is largely protected from timber harvest under the Northwest Forest Plan, but wildfire is still a primary threat to the old-growth forest that spotted owls rely on for nesting habitat,” said research wildlife biologist Damon Lesmeister. “The loss of spotted owl nesting habitat as a result of severe fire damage could have significant negative impacts on the remaining spotted owl populations as well as a large number of other wildlife species that rely on these old forests.”
Old-growth forests have more vegetation than younger forests. Researchers expected that this meant more fuel would be available for wildfires, increasing the susceptibility of old-growth forests to severe fire, high tree mortality, and resulting loss of critical spotted owl nesting habitat. However, the data suggested a different effect.
Lesmeister and his colleagues classified fire severity based on the percentage of trees lost in a fire, considering forest that lost less than 20% of its trees to fire subject to low-severity fire and those with more than 90% tree loss subject to high-severity fire. They found that old-growth forest was up to three times more likely to burn at low severity—a level that avoided loss of spotted owl nesting habitat and is generally considered to be part of a healthy forest ecosystem.
“Somewhat to our surprise, we found that, compared to other forest types within the burned area, old-growth forests burned on average much cooler than younger forests, which were more likely to experience high-severity fire. How this actually plays out during a mixed-severity wildfire makes sense when you consider the qualities of old-growth forest that can limit severe wildfire ignitions and burn temperatures, like shading from multilayer canopies, cooler temperatures, moist air and soil as well as larger, hardier trees.”
Because old-growth forests may be refuges of low-severity fire on a landscape that experiences moderate to high-severity fires frequently, they could be integral as biodiversity refuges in an increasingly fire-prone region. Leveraging the potential of old-growth forests to act as refuges may be an effective tool for forest managers as they deal with worsening fire seasons in the Pacific Northwest.
The study was a collaboration between researchers Damon Lesmeister and David Bell, USDA Forest Service, Pacific Northwest Research Station; Stan Sovern and Matthew Gregory, Oregon State University; Raymond Davis, USDA Forest Service, Pacific Northwest Region; and Jody Vogeler, Colorado State University.
The USDA Forest Service Pacific Northwest Research Station—headquartered in Portland, Ore.—generates and communicates scientific knowledge that helps people make informed choices about natural resources and the environment. The station has 11 laboratories and centers located in Alaska, Washington, and Oregon and about 300 employees.
Read the paper: Ecosphere
Article source: USDA Forest Service – Pacific Northwest Research Station
Image: USDA Forest Service photo by Damon Lesmeister
More than half of the carbon sink in the world’s forests is in areas where the trees are relatively young – under 140 years old – rather than in tropical rainforests, research at the University of Birmingham shows.
These trees have typically ‘regrown’ on land previously used for agriculture, or cleared by fire or harvest and it is their young age that is one of the main drivers of this carbon uptake.
Forests are widely recognised as important carbon sinks – ecosystems capable of capturing and storing large amounts of carbon dioxide – but dense tropical forests, close to the equator have been assumed to be working the hardest to soak up these gases.
Researchers at the Birmingham Institute of Forest Research (BIFoR) have carried out fresh analysis of the global biosphere using a new combination of data and computer modelling in a new study published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS). Drawing on data sets of forest age, they were able to show the amount of carbon uptake between 2001 and 2010 by old, established areas of forest.
They compared this with younger expanses of forest which are re-growing across areas that have formerly experienced human activities such as agriculture or logging or natural disturbances such as fire.
Previously it had been thought that the carbon uptake by forests was overwhelmingly due to fertilisation of tree growth by increasing levels of carbon dioxide in the atmosphere.
However, the researchers found that areas where forests were re-growing sucked up large amounts of carbon not only due to these fertilisation effects, but also as a result of their younger age. The age effect accounted for around 25 per cent of the total carbon dioxide absorbed by forests. Furthermore, this age-driven carbon uptake was primarily situated not in the tropics, but in the middle and high latitude forests.
These forests include, for example, areas of land in America’s eastern states, where settlers established farmlands but then abandoned them to move west towards the end of the 19th century. The abandoned land became part of the US National Forest, along with further tracts abandoned during the Great Depression in the 1930s.
Other significant areas of forest re-growth include boreal forests of Canada, Russia and Europe, which have experienced substantial harvest activity and forest fires. Largescale reforestation programmes in China are also making a major contribution to this carbon sink.
Dr Tom Pugh, of the Birmingham Institute of Forest Research (BIFoR), explained: “It’s important to get a clear sense of where and why this carbon uptake is happening, because this helps us to make targeted and informed decisions about forest management.”
The research highlights the importance of forests in the world’s temperate zone for climate change mitigation, but also shows more clearly how much carbon these re-growing forests can be expected to take up in the future. This is particularly important because of the transient nature of re-growth forest: once the current pulse of forest re-growth works its way through the system this important part of the carbon sink will disappear, unless further reforestation occurs.
“The amount of CO2 that can be taken up by forests is a finite amount: ultimately reforestation programmes will only be effective if we simultaneously work to reduce our emissions,” explains Dr Pugh.
Read the paper: PNAS
Article source:University of Birmingham
Image credit: CCO Public domain
