but sustainability studies are needed at population level to insure the protection of this beautiful species. Dracaena kaweesakii is thought to be endangered through having a limited distribution destruction of limestone for concrete and extraction of trees for gardens comments Dr Wilkin
In fact in some regions the magnitude of carbon uptake or release due to the effects of specific animal species or groups of animals--such as the pine beetles devouring forests in western North america--can rival the impact of fossil fuel
In one case an unprecedented loss of trees triggered by the pine beetle outbreak in western North america has decreased the net carbon balance on a scale comparable to British columbia's current fossil fuel emissions.
Tree-killing insects and plant diseases are natural elements of healthy forest ecosystems but climate change is rapidly altering the distribution and magnitude of forest pestilence and altering biodiversity and the ecosystem.
For example pine bark beetles have killed recently trees over more area of U s. forests than wildfires including in areas with little previous experience managing aggressive pests.
That has permitted population explosions of tree-killing bark beetles in forests that were shielded previously by winter cold
But tree growth rates in many regions are increasing due to atmospheric change which may increase resilience to pests.
In Eastern temperate forests like those in Great smoky mountains national park the most sensitive elements of the ecosystem are the hardwood trees
#Massive spruce beetle outbreak in Colorado tied to droughta new University of Colorado Boulder study indicates drought high in the northern Colorado mountains is the primary trigger of a massive spruce beetle
because it shows that drought is a better predictor of spruce beetle outbreaks in northern Colorado than temperature alone said lead study author Sarah Hart a CU-Boulder doctoral student in geography.
Drought conditions appear to decrease host tree defenses against spruce beetles which attack the inner layers of bark feeding
which impedes tree growth and eventually kills vast swaths of forest. Spruce beetles like their close relatives mountain pine beetles are attacking large areas of coniferous forests across the West.
While the mountain pine beetle outbreak in the Southern Rocky mountains is known the best and appears to be the worst in the historical record the lesser known spruce beetle infestation has the potential to be equally
or even more devastating in Colorado said Hart lead author on the new study. It was interesting that drought was a better predictor for spruce beetle outbreaks than temperature said Hart of the geography department.
The study suggests that spruce beetle outbreaks occur when warm and dry conditions cause stress in the host trees.
A paper on the subject was published online in the journal Ecology. Co-authors include CU-Boulder geography Professor Thomas Veblen;
former CU-Boulder graduate student Karen Eisenhart now at Edinboro University of Pennsylvania; and former CU-Boulder students Daniel Jarvis and Dominik Kulakowski now at Clark University in Worcester Mass.
The new study also puts to rest false claims that fire suppression in the West is the trigger for spruce beetle outbreaks said Veblen.
Spruce beetles range from Alaska to Arizona and live in forests of Engelmann spruce and subalpine fir trees in Colorado.
The CU-Boulder team assembled a long-term record of spruce beetle outbreaks from the northern Front Range to the Grand mesa in western Colorado using a combination of historical documents
and tree ring data from 1650 to 2011. Broad-scale outbreaks were charted by the team from 1843-1860 1882-1889 1931-1957 and 2004 to 2010.
These are two things that easily can get mixed together in most tree ring analyses.
There are several lines of evidence that drought is the main driver of the spruce beetle outbreak.
when northwest Colorado was in a warm wet climate period from 1976 to 1998 for example both spruce beetle reproduction
and tree defenses like pitching beetles out of tree interiors with resin were likely high.
The strongest climate correlation to spruce beetle outbreaks was above average annual values for the Atlantic Multi-decadal Oscillation or AMO a long-term phenomenon that changes sea-surface temperatures
A 2006 tree-ring study involving Veblen his former student Thomas Kitzberger and researchers from several other institutions concluded that the warm phase of AMO also was correlated to increased wildfires in the West.
and the Pacific Decadal Oscillation--as well as past temperatures precipitation and aridity to better understand the spruce beetle outbreaks.
In the new study the researchers were interested particularly in radial growth rates of tree rings from sub-canopy trees of various species in the study areas that thrived following outbreaks.
One hallmark of spruce beetle outbreaks is that slow radial growth rates in such areas are followed by extremely rapid radial growth rates an indication smaller trees flourish in the absence of the larger spruce trees
In 2012 U s. Forest Service surveys indicated that more area was under attack by spruce beetles than mountain pine beetles in the Southern Rocky mountains
One big concern about spruce beetle outbreaks is their effects on headwater streams that are important for water resources said Veblen.
In the short term trees killed by spruce beetles will lead to less water use by trees
But in the long term the absence of the trees killed by beetles may lead to less persistence of snow and earlier runoff.
Veblen said it might seem counterintuitive to some that spruce-fir subalpine forests in Colorado are larger by area than lodgepole/ponderosa pine forests.
But potentially the current spruce beetle outbreak could affect a larger area than the mountain pine beetle outbreak.
when Veblen and his students began compiling spruce and subalpine fir tree rings from various study sites in the Colorado mountains.
Tree rings from individual trees--which carry information about weather climate and even events like volcanic eruptions--can be matched up
and read with rings from other trees much like the pages of a book from year to year and even from season to season.
Story Source: The above story is provided based on materials by University of Colorado at Boulder. Note:
diet improves healthpolyphenols are naturally occurring compounds found largely in fruits vegetables coffee tea nuts legumes and cereals.
#New potential for nutrient-rich prairie fruitsresearchers working at the University of Saskatchewan have discovered new potential in prairie fruits in particular buffaloberry chokecherry
Thus our work supports the commercial development of buffaloberry chokecherry and sea buckthorn berries. According to the study:
This phylogeny or evolutionary tree provides a new framework for understanding the evolution of nesting feeding and social behavior in Hymenoptera.
and suggests that it is treated best as a lineage close to the root of the ant-apoid tree perhaps not assignable with certainty to either branch.
and how they fit into the tree of life is key to understanding this important human disease.
The parasites'natural hosts are African thicket rats that use shrubs and trees as habitat.
The DNA from several genes of the bat parasites was sequenced at the Museum's Sackler Institute for Comparative Genomics resulting in the most comprehensive evolutionary tree of life for malaria parasites of bats to date.
which roost in trees may have been exposed to the same mosquito vectors that transfer the parasites between the tree-dwelling rodent hosts.
We are already working on a study of fossil spruce she said. We hope that texture can be used to tell apart four species including one extinct spruce
and allow us to reconstruct the population dynamics of these species during the end of the last Ice age in the southeastern U s. This may explain why three of these species were able to migrate
Lateral roots as the name implies are secondary roots that grow laterally out of a plant's main root much like branches grow out of the trunk of a tree.
After all says Rattan Lal presider of the symposium There is no substitute for water. Story Source:
This result is an important validation of the approach we are taking to treat allergic diseases said Mark Larch who led the design of the treatments.
Larch is a professor of medicine of the Michael G. Degroote School of medicine at Mcmaster and member of the Firestone Institute for Respiratory Health at St joseph's Healthcare Hamilton.
#Death of a spruce treeexamining a long-lived forest researchers have found that Black spruce trees which dominate the northern forests of North america succumb about five years after being weakened by environmental stresses.
Without rejuvenating fire the dead trees aren t being replaced by new ones. The result will help researchers better understand how climate change affects the health of forests
The study also suggests trees might be storing more carbon than currently estimated. The take away from this is that a combination of short
Appearing in the journal Global Change Biology the study showed that tree growth slows down as forests age as expected.
The study also allowed the researchers to examine tree mortality--information needed to figure out how much carbon dioxide trees can store--to improve climate models.
and forests Bond-Lamberty and his international group of colleagues combined data from tree rings
and by watching how many trees died over 13 years in a northern Canadian boreal forest.
and are full of evergreen trees. The forest has been studied well in the past--it was the site of the NASA-led BOREAS project in the 1990s a study that provided scientists with a lot of
The tree ring data included tree core samples collected in three different years between 2001 and 2012 in a region called the Northern Old Black spruce site.
Such data tell scientists how fast trees grow every season over decades or hundreds of years.
The team found that the oldest trees started growing in the mid-1800s. Since then the stand of trees has gone through at least three dry periods evident from very thin rings during those periods.
Although tree rings can show how trees grow over the years they can't tell scientists when trees die.
For that researchers had to go walking through the forest taking inventory of what was there.
and dead tree that had grown at least chest high and measured their diameters as well. The researchers found that only three new trees of chest height entered the inventory during those 13 years
whereas many more died and others fattened. Meanwhile leaf cover stayed the same. Bond-Lamberty said this isn't surprising to see in a forest that hasn't seen a wildfire in a long time.
along with climate data from the same 150-year period they could clearly see the link between periods of slow growth and dead trees later on.
We see a five-year lag between depressed growth in the tree core data and increase of deaths in mortality data said Bond-Lamberty.
Trees are dying and not getting replaced but the average tree growth is bigger. People usually say that young forests take up carbon dioxide fast and store it away
while older forests are probably neutral. Our study shows that as trees die in an old forest middle-aged trees fatten up.
Thirsty Treesthis study also might cause scientists to reevaluate BOREAS results said Bond-Lamberty. Data from BOREAS allows researchers to estimate how much carbon dioxide trees pull out of the atmosphere
and store within their structures a value used in some models to predict the role of forests in a future warmer world.
Although this study in particular did not observe that trees are growing faster in the industrial age due to more carbon dioxide in the air knowing how long it takes for trees to die will be important for scientists trying to work that out.
From about 1920 to 1940 was a terrible time to be a tree. They were having a tough time staying alive
or if the stand was subject to unusual conditions the team compared the Northern Old Black spruce to a stand of slightly younger 80 year old Black spruce trees about three miles away.
Comparing the two stands of trees to each other showed similar results indicating that what was happening in the Northern Old Black spruce forest was happening elsewhere as well.
To understand current forest dynamics said Bond-Lamberty we have to understand their past. Older forests contain surprises for climate science and ecosystem biology.
#Early spring warming has greatest effect on breaking budthe timing of the first leaves on trees
With colleagues from the Marine Biological Lab at Woods Hole and the University of Georgia Clark is working on building a statistical model of how trees make this decision.
A mix of native trees are living in open-topped temperature-controlled chambers in natural forests.
It was thought that the trees were programmed to experience a certain amount of chilling and then warming Clark said.
Flowering plants evolved from extinct plants related to conifers ginkgos cycads and seed ferns. The oldest known fossils from flowering plants are pollen grains.
when the city of Houston called for ideas about how to get rid of the estimated 5. 6 million cubic yards of fallen trees broken branches
#First long temperature reconstruction for the eastern Mediterranean based on tree ringsfor the first time a long temperature reconstruction on the basis of stable carbon isotopes in tree rings has been achieved for the eastern Mediterranean.
The analysis of carbon isotope ratios (13c/12c) in tree rings aims to close this research gap.
By focusing on the months January to May the researchers detected the period in which the trees shift from dormancy in late winter to re-activation of growth in early spring.
The carbon isotope ratios measured in individual tree rings largely depends on the environmental conditions; thus the varying tree-ring isotope values are good indicators for changes in the environment.
The carbon isotope ratios in the trees from Turkey indicate a temperature sensitivity of the trees during late winter to early spring.
In cold winters the cambium and the leaves are damaged more than usual and the following recovery in spring takes longer.
Recently however a research team led by a University of California Davis plant scientist used DNA sequencing technologies to paint a broad picture of how citrus greening impacts trees before they even show signs of infection offering hope for developing diagnostic
and matures leaves and fruit while also wreaking havoc with hormonal networks that are key to the trees'ability to fend of infections.
These bacteria are carried from tree to tree by two species of the citrus psyllid a winged insect that is about one-eighth inch long
and attaches itself to the underside of the trees'leaves. As the citrus psyllid feeds on a leaf it can pick up the bacteria from a diseased tree
and introduce the bacteria to a non-infected tree. These disease-causing bacteria reside in the tree's phloem--the vascular tissue that carries vital nutrients throughout the tree.
The disease affects most citrus species causing yellowing of shoots blotchy and mottled leaves lopsided and poorly colored fruit and loss of viable seeds.
The fruit of diseased trees is hard misshapen and bitter and the infected trees die within a few years.
Other than one infected backyard tree found in 2012 in the Southern California community of Hacienda Heights the disease has not been detected in California.
However the citrus psyllid that transmits the bacteria was first found in California in 2008
In this new study the researchers studied four categories of healthy and diseased citrus trees with the goal of better understanding how HLB affects trees physiologically during the very early stages of infection.
or interfering with nutrient transport in the infected trees he said. The researchers used gene sequencing technology to study the transcriptome which is the collection of RNA found in the tree leaves and fruit.
Their analysis confirmed that in infected trees HLB disease caused starch to accumulate in the leaves blocking nutrient transport through the phloem
and decreasing photosynthesis. They also found that normal metabolism of sucrose a sugar also key to photosynthesis was disrupted.
And they found that infected trees also had changes in the metabolism of important amino acids that serve as a reservoir for organic nitrogen in many plants.
The researchers anticipate that these discoveries will lead the way to new tests for detecting the bacteria and thus the presence of HLB in orchard trees.
They also suggest that it may be possible to develop several short-term treatments for infected trees.
and other small molecules to restore the infected tree's normal metabolism or boosting the tree's innate immune response to effectively fight the infection.
Story Source: The above story is provided based on materials by University of California-Davis. Note: Materials may be edited for content and length.
#Seeing the forest and the trees: Panoramic, very-high-resolution, time-lapse photography for plant and ecosystem researchever wonder what plants do
Lurking in the hollows of old myrtle beech trees and thus hard to collect this extraordinary spider is an endemic species confined strictly to the beautiful Great Otway National park (Victoria Australia.
A single thick and shiny silk thread is used then by the spiders to provide a zip-line like connection between the external webs and the security of the enigmatic retreat in the hollows of ancient myrtle beech and mountain ash tree.
On one occasion we had access to a large hollow mountain ash tree and found catching ladders and supporting webs of juveniles inside of itcomments the lead author of the study Peter Michalik Zoological Institute
Martã n Ramã rez from the Argentinian Museum of Natural history and co-author of the study commented on the habitat specificity of this species confined to the oldest and extensively hollow myrtle beech trees in the humid forests in the western part of the Great
Otway National park or in mountain ash trees upon which the myrtle trees depend thus making an important case for the conservation of such habitats.
The unusual living habits and high degree of endemicity makes this spider a rare and remarkable species. The new study suggests that this spider is dependent on the microclimate in the hollows of old myrtle beech trees
since other hollow trees were very much less inhabited and to some extent explains the confinement of the species distribution range.
Story Source: The above story is provided based on materials by Pensoft Publishers. The original story is licensed under a Creative Commons License.
silvopastoral systems which include shrubs and trees with edible leaves or fruits as well as herbage. Professor Donald Broom from the University of Cambridge who led the research said:
The effects on the local environment include the removal of trees and shrubs as well as the increased use of herbicides all of
and encourages biodiversity using native shrubs and trees. Additionally shrubs and trees with edible leaves and shoots along with pasture plants produce more food for animals per unit area of land than pasture plants alone.
Trees and shrubs have added the benefit of providing shade from hot sun and shelter from rain.
It also reduces stress by enabling the animals to hide from perceived danger. The planting as forage plants of both shrubs
and trees whose leaves and small branches can be consumed by farmed animals can transform the prospects of obtaining sustainable animal production said Professor Broom.
Such planting of'fodder trees'has already been successful in several countries including the plant Chamaecytisus palmensis
#Uphill for the trees of the worldhuman civilisation has had an impact on the world and it continues to have an even greater impact.
The researchers analysed high-resolution global satellite data describing the distribution of tree cover in the period 2000-2005 linking this to global data for terrain (slope) climate human activity and a number of political and socioeconomic factors.
The more well-developed societies around the world are now increasingly replanting trees just as forests are naturally regrowing in areas that have been abandoned as people move to the cities.
#Why traumatized trees dont bleed to deathwhy don't bleed trees to death when they are injured? Researchers from Virginia Tech the Georg-August University of Gottingen Germany and the Jackson Laboratory of Bar Harbor Maine have discovered how check valves in wood cells control sap flow
and protect trees when they are injured. The study featured on the cover of the September issue of the American Journal of Botany used a special microscope to reveal how nanostructures help contain damage within microscopic cavities called bordered pits in wood-fiber cells.
It helps explain how trees seal off the cells of wood so that softwood trees don't bleed to death
'or lose all their sap when they are injured Goodell said. Without pectin a tree cannot defend itself
and it can't seal off damaged cells. The American Journal of Botany is one of the 10 most influential journals over the last 100 years in the field of biology and medicine according to the Biomedical & Life sciences Division of the Special Libraries Association.
When the tree is injured sap starts to flow out and air flows In this changes the partial pressure
In the living tree it allows sap to flow up the tree while also helping to prevent embolisms--the spread of air pockets in the tree.
In wood fallen to the forest floor it controls the rate that fungi advance through the wood cells to cause decay
His study of the brown rot fungi led him to study tree defenses at the nanostructure scale.
The mineral is a critical nutrient for healthy tree growth and new research shows that adding it to the soil helps reverse the decades-long decline of forests ailing from the effects of acid rain.
It is accepted generally that acid rain harms trees but the value of our study is that it proves the causal link between the chronic loss of soil calcium caused by decades of acid rain
and its impact on tree growth said Battles. The temporal and spatial scope of the study--15 years and entire watersheds--is unique
The researchers reported that trees in the calcium-treated watershed produced 21 percent more wood and 11 percent more leaves than their counterparts in an adjacent control site.
The iconic sugar maple--the source of maple syrup--was the tree species that responded most strongly to the restoration of calcium in the soil.
The research site managed by the U s. Forest Service was targeted because of the declining growth rates and unexpected death of trees in the area.
The trees in the calcium-treated watershed were able to recover faster from a severe ice storm that hit the region in 1998.
If you are considering adding new trees grasses and plants into your landscape be sure they aren't the worst offenders.
#¢Trees: Apple Dogwood Pear Plum Begonia flower#¢Plants and Flowers: Daffodil Lilac Magnolia Rose Sunflowerbe Quick to Clean--Mold and pollen can collect on fallen leaves.
Be sure to rake leaves often and wear a pollen mask while doing so since raking can stir allergens into the air.
Continue mowing your lawn throughout the fall and keep your grass short. Maintaining your lawn will keep grass from flowering
'Only by viewing forest sites along a gradient of logging disturbance ranging from pristine to heavily degraded were the team able to detect a gradual decline of some key bat species. The research confirmed the most vulnerable bats were those that tend to live in the cavities of old growth trees.
By linking bat captures with vegetation measurements from nearby plots the researchers were able to reveal how these animals declined as successive rounds of logging took their toll on forest structure and crucially the availability of tree cavities.
With support from the Sime Darby oil palm company and the Malaysian government the aim is to produce a set of science-based recommendations for more sustainable practices in the logging and agriculture industries in tropical countries.
Silberman and Brown perform comparative DNA sequence analyses of a type of eukaryote called protists to help find their particular placement or branch on the tree of life.
Most importantly the phylogenetic tree established the organism as a distant but unequivocal relative to a supergroup of eukaryotes that include fungi and animals.
In addition increased coffee consumption was associated non-linearly with a decreased risk of depression. In addition participation in a three-year lifestyle intervention study improved depression scores with no specific group effect.
#Tropical forest carbon absorption may hinge on an odd couplea unique housing arrangement between a specific group of tree species
The findings suggest that the role of tropical forests in offsetting the atmospheric buildup of carbon from fossil fuels depends on tree diversity particularly in forests recovering from exploitation.
Tropical forests thrive on natural nitrogen fertilizer pumped into the soil by trees in the legume family a diverse group that includes beans
The researchers studied second-growth forests in Panama that had been used for agriculture five to 300 years ago The presence of legume trees ensured rapid forest growth in the first 12 years of recovery and thus a substantial
Though the legumes'nitrogen fertilizer output waned in later years the species nonetheless took up carbon at rates that were up to nine times faster than non-legume trees.
which dwell in little pods inside the tree's roots known as root nodules. As a nutrient nitrogen is essential for plant growth
but tropical soil is short on nitrogen and surprisingly non-nutritious for trees. Legumes use secretions to invite rhizobia living in the soil to infect their roots and the bacteria signal back to initiate nodule growth.
and--in exchange for carbohydrates the tree produces by photosynthesis--convert nitrogen in the air into the fertilizer form that plants need.
Excess nitrogen from the legume eventually creates a nitrogen cycle that benefits neighboring trees. By nurturing bigger healthier trees that take up more carbon legumes have realized a newly importance
when it comes to influencing atmospheric carbon dioxide said second author Lars Hedin a Princeton professor of ecology and evolutionary biology and the Princeton Environmental Institute.
If trees could just grow and store carbon you could have a rapid sink but if they don't have enough nitrogen they don't take up carbon said Hedin adding that nitrogen-fixing trees are uncommon in temperate forests such as those in most of North america and Europe.
Legumes are a group of plants that perform a valuable function but no one knew how much they help with the carbon sink Hedin said.
but we do not know enough about how this valuable group of trees influences forests.
The researchers found that the nine legume species they studied did not contribute nitrogen to surrounding trees at the same time.
The researchers found that individual trees reduced their fixation as nitrogen accumulated in soils with the number of legumes actively fixing nitrogen dropping from 71 to 23 percent between 12-and 80-year-old forests.
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