now that shrubs are starting to recover following the re-introduction of wolves which have reduced over-browsing by elk herds.
The berry bushes also produce flowers of value to pollinators like butterflies insects and hummingbirds; food for other small and large mammals;
and health that they could be considered in legal disputes--as is white pine nut availability now--about
and willow trees--a favorite food--along with many berry-producing shrubs and tall herbaceous plants. The recovery of those trees and other food sources since the re-introduction of wolves in the 1990s has had a profound impact on the Yellowstone ecosystem researchers say
and shrub recovery and restore ecosystem health. As wolves help reduce elk numbers in Yellowstone
and shrub recovery researchers said this improves the diet and health of grizzly bears. In turn a healthy grizzly bear population provides a second avenue of control on wild ungulates especially on newborns in the spring time.
Yellowstone has a wide variety of nutritious berries--serviceberry chokecherry buffaloberry twinberry huckleberry and others--that are highly palatable to bears.
These shrubs are eaten also by elk and thus likely declined as elk populations grew over time.
And in the absence of wolves black bears went extinct on Anticosti Island in Canada after over-browsing of berry shrubs by introduced while-tailed deer.
Increases in berry production in Yellowstone may also provide a buffer against other ecosystem shifts the researchers noted--whitebark pine nut production a favored bear food may be facing pressure from climate change.
Grizzly bear survival declined during years of low nut production. Livestock grazing in grizzly bear habitat adjacent to the national park and bison herbivory in the park likely also contribute to high foraging pressure on shrubs
and forbs the report said. In addition to eliminating wolf-livestock conflicts retiring livestock allotments in the grizzly bear recovery zone adjacent to Yellowstone could benefit bears through increases in plant foods.
which allow them to consume more tree bark and less fruit but they are still dependent on natural forests for their long term survival.
which allow them to consume more tree bark and less fruit but they are still dependent on natural forests for their long term survival.
it also attacks five other tuber pests. The researchers then did a laboratory test of a formula based on this virus. The result was as efficient as chemical products:
#Traditional forest management reduces fungal diversityin the beech groves of Navarre a team from the UPV/EHU-University of the Basque Country has analysed the influence exerted by forestry management on the fungi populations that decompose wood.
because fallen branches and trees tend to be cleared away. This wood if available ought to be decomposing as it is the habitat of many living beings like lignicolous fungi.
These fungi are capable of decomposing dead wood and turning it into organic and inorganic matter.
So clearing away the dead wood from the forests is ecologically harmful for the fungi.
Nerea Abrego-Antia and Isabel Salcedo-Larralde biologists in the Department of Plant Biology and Ecology of the UPV/EHU-University of the Basque Country have quantified recently this effect on fungi populations that live off dead
wood in various beech groves in Navarre. The main conclusion of the study is that forestry
and classical forest management are harming the community of saproxylic fungi. What is more the researchers have discovered that in the forests being exploited various fungi species are disappearing
and in some cases even whole families are affected. The conclusion of the research is crystal clear:
the clearing away of remains of dead wood is harming the populations of lignicolous or saproxylic fungi.
Yet many fungi have to be identified under the microscope although there are known species that are very large like the tinder fungus Fomes fomentarius.
But it is more difficult to gather samples of the rest and identify them and it takes longer.
After classifying the debris the fungal species existing in each were identified in other words the community of fungi existing in each twig.
However according to the research by Salcedo and Abrego the factor that exerts the most influence on the diversity of saproxylic fungi is the diversity of the woody debris not the volume of wood in other words that the nine groups classified should appear the maximum possible number of times.
At the same time the influence exerted by forest fragmentation on the presence of fungi is also being analysed.
and classical forest management are harming the community of saproxylic fungi at least in the zones studied.
the closest known non-disease causing relatives of the fungus that causes WNS. These fungi many of them still without formal Latin names live in bat hibernation sites
and even directly on bats but they do not cause the devastating disease that has killed millions of bats in the eastern United states. Researchers hope to use these fungi to understand why one fungus can be deadly to bats
while its close relatives are benign. The study by Andrew Minnis and Daniel Lindner both with the U s. Forest Service's Northern Research Station in Madison Wis. outlines research on the evolution of species related to the fungus
causing WNS. The study is available online from the journal Fungal Biology. Identification of the closest known relatives of this fungus makes it possible to move forward with genetic work to examine the molecular toolbox this fungus uses to kill bats according to Lindner a research plant pathologist.
Ultimately we hope to use this information to be able to interrupt the ability of this fungus to cause disease.
The study is an important step toward treating WNS according to Mylea Bayless Bat Conservation International's director of conservation programs in the U s. and Canada.
This research increases our confidence that this disease-causing fungus is in fact an invasive species Bayless said Its presence among bats in Europe where it does not cause mass mortality could suggest hope for bats suffering from this devastating wildlife disease.
which the fungus belongs resulting in a new name: Pseudogymnoascus destructans or P. destructans. This research represents more than just a name change according to Bayless.
Understanding the evolutionary relationships between this fungus and its cousins in Europe and North america should help us narrow our search for solutions to WNS.
For this study in particular USGS and Fish & Wildlife Service partners played critical roles collecting the fungi used in these studies.
How plants set the angles of their branchesresearchers at the University of Leeds have discovered how plants set the angles of their branches.
and maintain the angle of their lateral branches relative to gravity. The mechanism is fundamental to understanding the shape of the plants around us:
explaining how for instance a young Lombardy poplar sends its branches up close to the vertical while an oak sapling's spread is much flatter.
different varieties within species often have very distinct root-system architectures that are determined mainly by the growth angle of lateral roots Kepinski said.
and shoot branches is not usually set relative to the main root or stem from which they grow but relative to gravity.
If a plant is put on its side these branches will begin a phase of bending growth known as gravitropism that reorientates them back toward their original angle of growth relative to gravity.
In the case of the main root or stem which grows upright the mechanism is understood well:
gravity sensing cells called statocytes detect that the plant has been tilted prompting an increase in the movement of a growth-regulating hormone called auxin to the lower side of the shoot or root and driving upward growth
in the shoot and downward growth in the root. When growing vertically again the statocytes stop sending more auxin to one side than the other and the bending growth stops.
The conundrum for the researchers was that many of the angles in branch and root architectures are at an angle to gravity rather than being completely upright.
Scientists did not understand how plants were able to set relative to gravity the particular non-vertical angle of growth for their branches--known as their gravitropic set-point angle--that determines their architecture.
We have found that another growth component--the'anti-gravitropic offset'--counteracts the normal gravitropic growth in these lateral branches.
This offset mechanism sustains growth on the other side of a branch from the gravity-sensitive growth
and prevents the branch from being moved beyond a set angle to the vertical. It turns out that this countervailing growth is driven also by auxin the same hormone that causes gravity responsive growth on the lower side of the branch.
Branches that are growing close to the vertical have a weak anti-gravitropic offset while in branches that are growing out at shallow angles away from the vertical the anti-gravitropic offset is relatively strong.
Dr Kepinski added: You can compare it to the way a tank or paddle steamer is steered.
If you want to straighten up you balance the speeds--or in our case the'speed'of growth on either side of the branch.
In a given non-vertical branch the anti-gravitropic offset is constant while gravity responsive growth increases in magnitude according to how far the branch is away from the vertical generating a robust system for maintaining a whole array of branch angles.
The Leeds team proved the presence of the offset by using a clinostat which slowly rotates a plant growing on its side thereby withdrawing a stable gravity reference
and root branches displayed an outward bending growth away from the main root and shoot that would normally be masked by the interaction with gravity-sensitive growth.
The angle of growth of branches is an exceptionally important adaptation because it determines the plant's capacity to capture resource above and below ground.
Similarly in the shoot a plant might gain an advantage from having more steeply pitched branches to avoid shading from neighbouring plants.
because breeders and seed companies want to be able to alter plant architecture to optimise the performance of crops.
For example lateral root growth angle has been shown to be critical for increasing nutrient uptake in both broadleaf and cereal crop species. Our findings provide tools
The team used the flowering plant Arabidopsis thaliana (thale cress) as well as pea bean and rice plants in their experiments observing the same results.
Kepinski expects the same mechanism to be observed in larger plants and young tree seedlings. In older trees the mechanisms driving gravity sensitive growth in woody tissues are different to those in non-woody plants.
Nevertheless Kepinski says the same general principles may apply. Story Source: The above story is provided based on materials by University of Leeds. Note:
Professor Edward Cocking Director of The University of Nottingham's Centre for Crop Nitrogen fixation has developed a unique method of putting nitrogen-fixing bacteria into the cells of plant roots.
when he found a specific strain of nitrogen-fixing bacteria in sugar-cane which he discovered could intracellularly colonise all major crop plants.
Applied to the cells of plants (intracellular) via the seed it provides every cell in the plant with the ability to fix nitrogen.
Plant seeds are coated with these bacteria in order to create a symbiotic mutually beneficial relationship and naturally produce nitrogen.
which have established proof of principal of the technology in the laboratory growth rooms and glasshouses.
Larvae of some species in the order Tetraodontiforme like the pufferfish and those in the order Lophiiforme like the anglerfish are strikingly similar in having the trunks of their bodies enclosed in an inflated yellow sac.
They analyzed the samples to find out which flowering plants were the bees'main pollen sources and
But when the researchers collected pollen from bees foraging on native North american crops such as blueberries and watermelon they found the pollen came from other flowering plants in the area not from the crops.
The fruit and seeds of the oil palm are the source of nearly one-half of the supply of edible vegetable oil worldwide
and land usethe discovery of the Shell gene and its two naturally occurring mutations highlight new molecular strategies to identify seeds
Seed producers can now use the genetic marker for the Shell gene to distinguish the three fruit forms in the nursery long before they are field-planted.
Both palm species are in the Arecaceae family of flowering plants which fossil evidence dates to the Cretaceous period an estimated 140 to 200 million years ago.
The authors warn that such plantations greatly reduce areas available for seed dispersing wildlife. Another emerging problem for Central africa's forests is the migration of large numbers of people into remote forests around the new plantations
They add that efficiently managed multiple-use landscapes--combining protected areas alongside logging concessions--can maintain the seed-dispersing species
The removal of seed-dispersing megafauna such as elephants and apes could reduce the ability of forests to sequester carbon.
which has declined significantly the Orangetip (Anthocharis cardamines) which seems to be stable since 1990 and the Lulworth Skipper (Thymelicus acteon)
and high-resolution airborne Light Detection and Ranging (Lidar) data to map the vegetation and to quantify carbon stocks throughout the Republic of Panama.
Importantly it can be used across a wide range of vegetation types worldwide. The new system described in Carbon Balance
Lidar uses reflected laser light to image vegetation canopy structure in 3-D. The scientists calibrated the Lidar measurements taken at one-meter resolution throughout nearly one million acres (390000 hectares) to the carbon
but it is low resolution both spatially and in terms of the structural information about the vegetation described Carnegie author Joseph Mascaro.
The researchers then were able to scale up the plot and Lidar data with freely available satellite data on topography rainfall and vegetation to model carbon stocks at the national level.
#Bees betray their flowers when pollinator species declineremove even one bumblebee species from an ecosystem and the impact is swift and clear:
Their floral sweethearts produce significantly fewer seeds a new study finds. The study to be published by the Proceedings of the National Academy of Sciences focused on the interactions between bumblebees and larkspur wildflowers in Colorado's Rocky mountains.
The results show how reduced competition among pollinators disrupts floral fidelity or specialization among the remaining bees in the system leading to less successful plant reproduction.
We found that these wildflowers produce one-third fewer seeds in the absence of just one bumblebee species says Emory University ecologist Berry Brosi who led the study.
That's alarming and suggests that global declines in pollinators could have a bigger impact on flowering plants
The National Science Foundation (NSF) funded the study co-authored by ecologist Heather Briggs of the University of California-Santa cruz. About 90 percent of plants need animals mostly insects to transfer pollen between them
while it's in bloom then a few weeks later move on to the next species in bloom.
The experiments focused on the interactions of the insects with larkspurs dark-purple wildflowers that are visited by 10 of the of the 11 bumblebee species there.
The researchers studied a series of 20-meter square wildflower plots evaluating each one in both a control state left in its natural condition
while in other cases they could follow the bees to 100 or more flowers. Running around after bumblebees in these beautiful wildflower meadows was one of the most fun parts of the research Brosi says.
Much of this bee team was made up of Emory undergraduate students funded by the college's Scholarly Inquiry
. While about 78 percent of the bumblebees in the control groups were faithful to a single species of flower only 66 percent of the bumblebees in the manipulated groups showed such floral fidelity.
Larkspurs produced about one-third fewer seeds when one of the bumblebee species was removed compared to the larkspurs in the control groups.
The small change in the level of competition made the remaining bees more likely to'cheat'on the larkspur Briggs says.
While previous research has shown how competition drives specialization within a species the bumblebee study is one of the first to link this mechanism back to the broader functioning of an ecosystem.
That feedback from the vegetation prevented fire frequency from increasing much more than it already was said Kelly.
and pressure created by the steam were sufficient to kill not just living microbes but also spores and viruses.
Loss of trees could impact on climate change as forests store carbon in their stems
and branches helping to reduce the amount of harmful carbon dioxide gas in the atmosphere. Tracking changes in woodland across the continent may help scientists better understand their effect on weather patterns
or sets of all genes of five 19th century strains of the Phytophthora infestans pathogen with modern strains of the pathogen
P. infestans caused massive and debilitating late-blight disease outbreaks in Europe leaving starvation and migration in its wake after ravaging Ireland in the mid-to-late 1840s.
Late blight is still a major threat to global food security in the developing world she adds. Knowing how the pathogen genome has changed over time will help modern-day farmers better manage the disease.
A new study to be published in Nature's The ISME Journal reveals the profound effect it has on enriching soil with bacteria fungi and protozoa.
Soil grown with peas was enriched highly for fungi. The soil around the roots was similar before
and after growing wheat but peas and oats reset of the diversity of microbes said Professor Poole.
(which include humans plants and animals as well as fungi). After only four weeks of growth the soil surrounding wheat contained about 3%eukaryotes.
It is now possible to sequence RNA across kingdoms so a full snapshot can be taken of the active bacteria fungi protozoa and other microbes in the soil.
The best seed needs to be combined with the best agronomic practices to get the full potential benefits.
Seeds can be inoculated with bacteria before planting out just like humans taking a dose of friendly bacteria.
The scientists also grew an oat variety unable to produce normal levels of avenacin a compound that protects roots from fungal pathogens.
They expected the soil to contain higher levels of fungi as a result but instead found it contained a greater diversity of other eukaryotes such as protozoa.
and effects on soil microbes surrounding the roots said Professor Poole. Scientists breeders and farmers can make the most of these effects not only with
and twice became a weed--and what it means for the futurethe evolutionary biologist Stephen Jay Gould once asked
which was bred from its wild progenitor Oryza rufipogon in southern Asia within the past 10000 years.
Whether the familiar indica and japonica subspecies of Asian rice also represent independent domestications is controversial.
Most of the rice grown in the U s. is japonica rice Olsen says which is genetically pretty different from indica rice the rice grown in a lot of the tropics.
In rice the syndrome includes loss of shattering (the seeds don't break off the central grain stalk before harvest) increase in seed size
and loss of dormancy (the seeds all germinate at once and can be harvested at once). Do the same genetic mutations underlie the emergence of these traits in both the Asian
-colored hulls and white grains of both Asian and African cultivated rice. So both Asian and African cultivated rice broke at roughly the same places under selection pressure from early farmers.
Because the weedy forms are closely related to rice varieties that were grown never in the U s. they probably arrived as contaminants in grain stocks from Asia instead of evolving directly from the tropical japonica crops grown here.
For example the weeds carry the crop form of the loss-of-shattering gene which means that they branched off from the crops sometime after people selected for loss of shattering.
Weeds stealing crop genesthe most important part of this story Olsen says is that the genetic histories of the crops
and the weeds are intertwined closely. This means the weedy forms can draw on both ancestral genes
The reason is that rice seedlings were grown traditionally in paddies and then transplanted to the fields by hand.
and pull weeds growing there But on industrialized farms rice is sprouted directly in the field so there's no opportunity to remove weeds.
Because the seedlings of both weedy and cultivated rice look alike farmers often don't realize they have a problem until the field is infested really.
Weedy infestations can drop the yield by as much as 80 percent Olsen says. If a field is infested heavily the farmer's only recourse may be to abandon it.
But that places huge pressure on the weeds to acquire herbicide resistance by hook or by crook.
So it would be pretty easy for random mutations to confer resistance on the weeds.
The other possibility is that resistance genes will migrate from the crop to the weeds.
But the crop and the weeds--which are after all the same species--could easily hybridize
It's going to change the overall composition of the weeds in U s. rice fields and presumably elsewhere in the world as well.
The new species was collected in a narrow river valley dominated by mountain sainfoin (Onobrychis cornuta) wild almond (Prunus amygdalus) scoparia) and downy brome (Bromus tectorum.
Many species feed on foliage and seeds whereas others bore through stems and fruits. Larvae of some species are known as cutworms
and live in the soil near the soil surface and they bite off young plants just above ground level at night.
They also can be derived from cane sugar and seaweed for use as a low-calorie (1. 5--2 Kcal/g) food sweetener and supplement.
However it has also been suggested that species characteristics are less important as determinants of plant establishment success than other factors such as seed availability or environmental characteristics like dense vegetation.
In a comprehensive field experiment the scientists sowed more than 90 different native and exotic plant species into 16 grasslands with different vegetation densities in the Canton of Bern.
They varied the introduced seed number and manipulated soil disturbance. Then they observed carefully which of the sown plant species established in the field.
At the same time the scientists conducted several greenhouse experiments to assess as accurately as possible the characteristics of each species--from seed mass
The winners are defended well against herbivoresthe Bernese plant scientists could show that at the beginning of the experiment mainly species with a high seed mass germinated in the grasslands.
In addition a high number of seeds sown increased early establishment success . However the importance of factors changed during the course of the study.
or ingredients especially those high in dietary fiber cereals and plant extracts nuts and seeds.
and filling in uncharted branches in the bacterial and archaeal tree of life. In an international collaboration led by the U s. Department of energy Joint Genome Institute (DOE JGI) the most recent findings from exploring microbial dark matter were published online July 14 2013 in the journal Nature.
and these would have to be selected based on being members of underrepresented branches on the tree.
#Sexual reproduction only second choice for powdery mildewgenetically powdery mildew is adapted perfectly to its host plants. Evidently sexual reproduction and new combinations of genetic material usually prove disadvantageous for the fungus.
Asexual reproduction however is considerably more successful for mildew as plant biologists from the University of Zurich
and the Max Planck Institute for Plant Breeding Research in Cologne demonstrate. Nonetheless the fungus still allows itself a sexual reproduction cycle.
Powdery mildew is one of the most dreaded plant diseases: The parasitic fungus afflicts crops such as wheat
and barley and is responsible for large harvest shortfalls every year. Beat Keller and Thomas Wicker both plant biologists from the University of Zurich and their team have been analyzing the genetic material of wheat mildew varieties from Switzerland England
and Israel while the team headed by Paul Schulze-Lefert at the Max Planck Institute for Plant Breeding Research in Cologne studies the genetic material of barley mildew.
The results recently published in Nature Genetics and PNAS respectively unveil a long shared history of co-evolution between the host and the pest and the unexpected success of asexually produced mildew offspring.
Moreover the data provides fresh insights into the crop history of wheat and barley and their interaction with the mildew pathogen.
Asexually produced offspring more successfullike other fungi mildew reproduces in two ways: Sexually where the genetic material is recombined
and asexually where the offspring and the mother fungus are genetically identical. The researchers now demonstrate that the success of the two reproduction methods could not be more different:
Mildew fungi detected on afflicted host plants have reproduced only successfully sexually every few centuries primarily reproducing asexually
instead explains Wicker. This baffling fact has more deep-rooted causes: In order to infect the host plant the mildew fungus needs to be able to successfully disable the plant's defense mechanisms--the parasite has to be adapted perfectly to its host.
In a parasite-host situation new combinations of genetic material are a disadvantage for the parasite as the adaptation to the host
and its defense mechanisms deteriorates as a result. Genetically identical offspring of successful mildew fungi that have already been able to infect the host plant
however have the ideal genetic prerequisites to be able to attack a host themselves. According to Schulze-Lefert wheat and barley mildew offspring from asexual reproduction are normally more successful than their sexually reproduced counterparts.
Asexual reproduction as a success model seems to be characteristic of many parasitic fungi including those that afflict humans such as athlete's foot.
Sex still worthwhilebased on the gene analyses the scientists were also able to prove that mildew already lived parasitically on the ancestral form of wheat 10000 years ago before wheat were domesticated actually as crops.
None of the subsequent genetic changes in the crops due to breeding or spontaneous mutations was ever able to keep the mildew fungus away from wheat in the longer term.
And this is precisely where the advantage of sexual reproduction lies and why the usually unsuccessful sexual reproduction cycle is still worthwhile for the mildew fungus:
Wheat and mildew are embroiled in a permanent evolutionary arms race. If wheat improves its defense mechanisms against the parasites the fungus has to be able to follow suit
or it has lost explains Wicker. That's only possible by recombining the genetic material; in other words sexual reproduction.
Evidently a sexual exchange and mixtures of the genetic material of different mildew varieties have occurred several times in the course of the millennia giving rise to new mildew varieties that were able to attack new sorts of wheat.
The scientists suspect that the grain trade in the ancient world was partly responsible for the emergence of new mildew varieties.
Story Source: The above story is provided based on materials by University of Zurich. Note: Materials may be edited for content and length.
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011