#Forest corridors help plants disperse their seeds, study showsa forest in South carolina a supercomputer in Ohio and some glow-in-the-dark yarn have helped a team of field ecologists conclude that woodland corridors connecting patches of endangered plants not only increase dispersal of seeds
from one patch to another but also create wind conditions that can spread the seeds for much longer distances.
The idea for the study emerged from modern animal conservation practices where landscape connectivity--the degree to
and seed dispersal in open habitats was published in the March 4 issue of Proceedings of the National Academy of Sciences of the United states of america and referenced in the February 27 issue of Nature.
and humidity at roughly 20 points throughout the experimental landscape Seed traps sampled seed arrival at many points in
and around the gaps and hundreds of artificial seeds made of black-light fluorescent yarn were released
These very large experimental efforts provided a novel dataset of observations of seed movement and wind in patch-corridors landscapes.
and seeds movement and the forest structure are known. Bohrer ran the dataset through a high-resolution atmospheric model that he had developed on OSC's IBM Opteron 1350 Glenn Cluster.
and seeds that disperse with it through a forest Bohrer said. The model resolves the wind flow
It also represented millions of dispersing virtual seeds. The model calculated the movement of the air and virtual seeds 20 times per second over four hours.
We found that corridors could affect the wind direction and align the wind flow with the corridor that they accelerate the wind
Benefits included increased carbon and nitrogen in soils erosion prevention more mycorrhizal colonization--beneficial soil fungus that helps plants absorb nutrients--and weed suppression.
For example nutrient-retention benefits occur primarily during cover crop growth weed-suppression benefits occur during cash-crop growth through a cover crop legacy effect
The cover crop rotation included red clover frost-seeded into winter wheat in March and winter rye planted after corn was harvested in the fall.
The research funded by the U s. Department of agriculture used simulated management practices including tillage synthetic fertilizer use and mechanical weed control.
The planting of cover crops already is accepted as an environmentally prudent practice. It is so beneficial in fact that the National Resource Conservation Service last month set a goal to increase the acres planted nationally in cover crops from the current 2 million to 20 million by 2020.
In particular the presence of large densities and varieties of flowering plants supports a number of pollinating insects
and northern Asia) and non-Palaearctic garden plants bees simply visited plants in proportion to flower availability. Indeed of the six most commonly visited garden plants only one--Foxglove--was a British native and only three of Palaearctic origin.
Among individual species however there were distinct preferences with the long-tongued'garden bumblebee'(Bombus hortorum) showing a strong preference for'native'Palaearctic-origin garden plants choosing them for 78%of its flower visits.
Meanwhile the UK's most common species--the'buff-tailed bumblebee'(Bombus terrestris)--favoured non-Palaearctic garden plants over species with
Dr Hanley added As a general rule bees will go wherever there are flowers available. However if native plants were to disappear completely from our towns
In addition to growing truly native plants like foxgloves where possible gardeners can help native pollinators by setting aside a small area to allow native brambles vetches dead nettles
and clovers to grow. But as long as some native species are available in nearby allotments parks
#Preventing Head blight in Barley, Wheat: Biochemical Pathways Hold Key to Resistancepale shriveled heads of grain spell trouble for wheat
and barley farmers--they're the telltale signs of fusarium head blight. The fungal disease commonly known as scab not only dramatically shrinks yields
From 1991 to 1996 head blight caused $2. 6 billion in losses to the U s. wheat crop.
At its peak the fungus destroyed the entire malting barley crop in the Red river and Ohio river Valleys according to molecular biologist Yang Yen an Agricultural Experiment Station researcher and professor at South dakota State university.
Two decades later the U s. Department of agriculture still ranks head blight as the worst plant disease to hit the U s. since the rust epidemics in the 1950s.
and Barley Scab Initiative scientists admit that efforts to control this devastating disease have met with limited success. This is an extraordinary disease that requires extraordinary means to combat it says Yen who began working on head blight in 1997.
Using advanced genetic and molecular technologies Yen has begun tracing the biochemical pathways that make wheat susceptible or resistant to head blight.
Multiple hosts and pathogens Head blight can be caused by multiple pathogens and these pathogens can attack multiple hosts including grasses
Fusarium spores exist during winter in the plant debris. Even plowing the stubble under does not eliminate the problem
because the fungus also survives in the ground. Wind and rain splash carry the spores onto the head
when it flowers but the weather conditions must be just right--warm humid and wet. The wheat flower must be open for the fungus to enter Yen explains.
In susceptible varieties the fungus kills the infected cells in the head thereby plugging the transport of water and nutrients to the upper part of the head.
While diseases such as stem rust want the host to survive Yen says fusarium attacks the wheat
or barley spikes and the kernels collapse because the fungus kills them and lives on the dead cells.
Sumai 3 successfully delays the development of the disease. Though the kernel on which the spore has landed will be empty it won't affect the rest of the head he explains.
But this variety has other undesirable characteristics and cannot be used here. Gene expression Yen has undertaken a molecular study of the disease investigating how the fungal infection impacts wheat gene expression.
He compared the most resistant varieties of wheat with the most susceptible ones. By looking at how genes were expressed the molecular biologist narrowed the possibilities from thousands of genes to 608 then to 47 and eventually to three.
and ethylene and then exposed it to head blight. The wheat resisted the fungi. Two of the three genes are involved directly in the chemical pathways Yen explains.
How the third one is involved we still do not know but it may play a key role
Disease development Essentially Yen hypothesizes that the fungus softens the host cell wall during infection and triggers a chain of host resistance responses.
In the susceptible wheat the disease makes the plant drop this gene expression so the fungus can get established.
and how the fungus suppresses the gene expression. Only then can the researcher figure out how to prevent the disease from becoming an epidemic.
Fusarium head blight results from close interaction between the fungus and the host. We need to understand how this interaction is occurring
When inexperienced bees encountered the most complex flower first they were unable to access the syrup reward
Bees allowed to progress through increasingly complex flowers were able to navigate the most difficult ones.
and vegetable crops which are highly perishable tend to have less regulation than the grains and oilseeds.
or access to the right seeds she said. There has been evidence that major famines weren't due to a lack of food production they occurred
#Reintroduction experiments give new hope for plant on brink of extinctiona critically endangered plant known as marsh sandwort (Arenaria paludicola) is inching back from the brink of extinction thanks to the efforts of a UC
Ingrid Parker the Langenheim professor of plant ecology and evolution at UC Santa cruz got involved in the marsh sandwort recovery effort at the request of the U s. Fish and Wildlife Service (USFWS.
Although it used to occur all along the west coast from San diego to Washington state this wetland plant with delicate white flowers had dwindled to one population in a boggy wetland in San luis Obispo County.
We planted out marsh sandwort in different habitats within a stone's throw of each other
A key finding was the discovery that a relatively common plant can serve as a useful indicator of good habitat for the endangered marsh sandwort.
Field experiments in two California State Parks in Santa cruz County showed that marsh sandwort does well in areas dominated by water parsley.
and light conditions that work well for this endangered species. That isn't to say that every place water parsley grows will be good for marsh sandwort
The researchers were thrilled to discover that plants in the reintroduced populations are flowering and setting seed.
but producing flowers and seeds in the field was fantastic. Arenaria cuttings root easily making it relatively straightforward to propagate large numbers of plants in the UCSC greenhouses.
Greenhouses director Jim Velzy will continue to maintain the collection of Arenaria plants to preserve the genetic diversity of the original population
in case it ever goes extinct in the wild. For the field studies Bontrager and coauthor Kelsey Webster another UCSC undergraduate worked closely with coauthor Mark Elvin a U s. Fish and Wildlife Service biologist.
With help from other undergraduates in Parker's lab they prepared the plots planted out marsh sandwort cuttings propagated in the UCSC greenhouses
This group the Neotropical bark mantises are incredibly fast runners that live on the trunks and branches of trees said Svenson of The Cleveland Museum of Natural history.
This violates the common perception of praying mantises being slow and methodical hunters. Like most praying mantises they are highly camouflage.
and is very difficult to locate because of their adept mimicry of bark moss and lichen.
In addition some species leap off the tree trunk to avoid capture and play dead after fluttering down to the forest floor
As highly visual predators the bark mantis species appear to be active hunters that pursue prey as opposed to ambush hunters that wait for prey to come close.
Also like a similar bark mantis group from Australia (Ciulfina) this Neotropical group does not appear to exhibit cannibalism
which is an often misunderstood characteristic exhibited by some praying mantis species. The research brings to light a previously unknown diversity of bark mantises.
Therefore as the silver layer thickens over time the tag color evolves from the initial red to orange yellow and green and even blue and violet.
Carbon balances showed that under the current climate lightly grazed dwarf-shrub-dominated tundra were a stronger carbon sink than heavily grazed graminoid-dominated tundra.
but humans can't.'Elephants appear to be able to manipulate their vocal tract (mouth tongue trunk and so on) to shape the sounds of their rumbles to make different alarm calls'said Dr Lucy King of Save the Elephants
or up their trunks whilst calves could potentially be killed by a swarm of stinging bees as they have yet to develop a thick protective skin.
DCA looks at the genetic roots of proteins to see how amino acids--the beads in the unfolded protein strands--co-evolved to influence the way a protein folds.
how muscle in general deals with something as complex as climbing a tree with its horizontal and vertical inclines the tiny little branches
and the upright trunks said Kathleen Foster a Ph d. student in Evolution Ecology and Organismal biology who performed the study.
The study found that muscle activity in the green anoles was most consistent on broad vertical surfaces such as tree trunks suggesting that
despite being classified as a trunk-crown ecomorph this species may prefer trunks Foster said. The study has implications also for people who design artificial limbs or robots.
However lignin must be removed for biofuel pulp and paper production-a process that involves harsh chemicals and expensive treatments.
#Soil microbes shift as shrubs invade remnant hill prairiesperched high on the bluffs of the big river valleys in the Midwest are some of the last remnants of never-farmed prairie grasslands.
These patches edged by forest are slowly being taken over by shrubs. A recent University of Illinois study examined the soil microbes on nine patches also called balds that had varying degrees of shrub invasion
and found an interesting shift in the composition of the microbial community. When we looked at the soil samples from a lightly encroached hill prairie remnant it was very clear that there was a set of fungi that look like grassland fungi a set of fungi that look like tree fungi
and the shrubs between the two have some features of both said U of I microbial ecologist Tony Yannarell.
As the degree of shrub encroachment increased the amount of change in the fungal communities also increased
and as the degree of shrub encroachment increased that shrub fungi joined the forest group to become one big woody community.
Yannarell said that on the balds that were encroached completely the soil samples across the entire remnant were the same.
You get this shift toward woody fungal communities that mirror how much shrub density you have in the hill prairie he said.
The microbes in the shrub soil tend to be different but different parts of the microbial community change in relationship to the shrub to the forest to the prairie.
The shrub bacteria are more like what they found in open prairie than in the forest.
But the shrub fungi looked a lot more like the forest fungi. We think what we found is the signature of these early changes these early shifts of microbial communities toward a woody fungal community Yannarell said.
We think we can firmly conclude that there are some woody plant-liking fungi. But we don't know
if there are shrub diseases. We're also interested in knowing if the shrubs have changed these microbes
because that could have an effect on a landowner's ability to restore a heavily encroached hill prairie Yannarell said.
If you cut down all of the shrubs you haven't changed the microbial communities that live in the soil that the shrubs created.
and now native shrubs such as dogwood sumac shrubby black locust and eventually red cedar move in. We don't know yet what kind of long-term impact this could have on the environment Yannarell said.
The shrubs could be driving out grass-loving fungi in favor of shrub-loving fungi.
Influence of Shrub Encroachment on the Soil Microbial Community Composition of Remnant Hill Prairies was published in the February 2014 issue of Microbial Ecology.
pepper plants nightshade and figs. The results revealed that bats flew into the dark compartment twice as often as the compartment lit by a street lamp.
and spreading their seeds especially the seeds of species that are first to recolonise cleared land.
In tropical habitats bat-mediated seed dispersal is necessary for the rapid succession of deforested land
because few other animals than bats disperse seeds into open habitats says Daniel Lewanzik doctoral candidate at the IZW and first author of the study.
Under naturally dark conditions bats produce a copious'seed rain 'when defecating seeds while flying.
By reducing foraging of fruit-eating bats in lit areas light pollution is likely to reduce seed rain he commented.
In many tropical countries light pollution is increasing rapidly as economies and human populations grow.
The characteristic leaf like structure protruding upwards from their nose is believed to be involved in focusing the bats'ultrasonic biosonar beam more precisely.
This is necessary since they mainly feed on fruit of pepper plants from the Genus piper that grow in the understory.
even dead trunks stayed largely intact for another 1000 years before rotting. One piece of wood they found had rings going back to about 650 B c. These yearly rings change with temperature
The heat evaporated water stored in soil lakes and vegetation and in combination with repeated dzuds devastated livestock.
These can be read somewhat like tree rings to estimate the abundance of livestock over time via layers of fungal spores that live in the dung of animals;
and weeds cause hay fever from the summer through the fall. Ragweed is often one of the biggest offenders in most regions as it can grow in nearly every environment.
There's no reason for people with allergies to suffer Dr. Rosenstreich said. As long as you take the proper precautions you should be able to enjoy the outdoors
consequently these small seldom-seen animals may play a significant role in regulating the capture of carbon from leaf litter in forest soils.
predation on invertebrates indirectly affects the amount of leaf litter retained for soil-building where nutrients
and how that influenced leaf litter retention. The study included soil moisture as a covariate and field enclosures on the forest floor to quantify the effects of woodland salamanders.
and shrubs with crops and livestock on farms--could be a win-win solution to the seemingly difficult choice between reforestation
and may also enhance agricultural productivity. In a special issue of Current Opinion in Environmental Sustainability scientists say that in most parts of Africa climate change mitigation focuses on reforestation
#Tuscanys badlands acutely endangeredvast fields of sunflowers sprawling pine trees and slim cypresses as well as vineyards as far as the eye can see--these are typical memories of Tuscany for all those who have been there.
But why asked the chair of Soil science is there a protective blanket of sage brush orchard grass wild rye
'this typically Tuscan landscape is the result of an intense interplay of the condition of the soil the vegetation and the land-use.
An additional reason can be found in the vegetation itself. In places where something once grew organic material finds its way into the ground
Moreover the vegetation leads to a better overall wetting mesh which adds to the greening
The excess is a special problem for grasslands where many plants like annual wildflowers and others have adapted to low nutrient levels.
and give the others a chance to bloom. Where we see a change in light we see a change in diversity said Borer the lead author.
The study Deer Browsing Delays Succession by Altering Aboveground Vegetation and Belowground Seed Banks was published online March 7 in PLOS ONE.
Deer typically prefer to eat native woody plants and rebuff invasive species. The study showed that
when deer consume native plants the nonnative species are left to flourish dropping seed in the soil.
and shrubs and then new trees eventually take root. Expanding deer populations in the Northeast however stall forest development
and promote the growth of thorny thickets of buckthorn viburnum and multiflora rose bushes. If deer leave the forests alone such trees as cottonwood locust
and sumac can sprout and grow unimpeded. The researchers found that the impacts of deer grazing on vegetation were resulted severe
and in bare soil and reduced plant biomass less recruitment of woody species and relatively fewer native species. And the deer's negative impact on seed banks resulted in significantly decreased overall species richness and relatively more short-lived species
of both annual and biennial plants. Co-author Antonio Ditommaso Cornell associate professor of weed ecology and management and research technician Scott Morris gathered soil cores--from both within and outside of fenced deer exclosures
--and germinated the seed. They found the soil cores from outside of the exclosures contained many more seeds from nonnative species. Deer select forests for their trees
but in doing so disrupt forest system growth trajectories concludes the study. It's obvious that the deer are affecting the aboveground species
but it's like an iceberg. There are major effects below the soil surface. We are seeing a divergence of seeds contained within the soil from what should be there says Ditommaso We are not seeing the seeds of woody plants.
Instead we're seeing an escalation of nonnative seed and the virtual elimination of woody plant seeds.
The multiyear study was conducted on Cornell land near Freese Road in Ithaca where the deer density is about 39 animals per square kilometer--about 10 times greater than it was before European settlement in the late 1700s.
In the case of old olive trees in the Mediterranean region it is not at all unusual for dead branches to stay in place for several decades says Paolo Cherubini.
By way of a'blind test'Cherubini recently asked 10 experts in five tree-ring laboratories in various countries to date the same wood samples from olive-tree branches.
1. mixing it in the stamp sand before planting seed; 2. coating seed with bacteria and planting it;
3. germinating seeds and planting them in soil to which bacteria were added; and4. the conventional method immersing the roots of maize seedlings in bacteria
and planting them in stamp sand. After 45 days the team uprooted the plants and measured their dry weight.
All maize grown with bacteria was significantly more vigorous--from two to five times larger--than the maize grown in stamp sand alone.
or as germinated seeds. However when the researchers analyzed the dried maize they made a surprising discovery:
the seed-planted maize took up far more copper as a percentage of dry weight. In other words the smaller plants pulled more copper ounce per ounce out of the stamp sands than the bigger ones.
The usual technique--applying bacteria to seedlings'roots before transplanting--works fine in the lab
and an increased rate of gains over the years are largely due to the continual release of greater-yielding cultivars by breeders.
and one Canadian province during 2010 to 2011 The experiments included plant introductions (PIS) and public cultivars obtained from the USDA Soybean Germplasm Collection housed at the National Soybean Research center at the U of
and have seeds with less protein and greater oil concentration. The new varieties tend to mature later within these maturity groups
Most of the yield increases are the result of breeders selecting better combinations of genes that can allow plants to take sunlight and produce more seed from that sunlight.
We don't know what genes breeders are selecting that are resulting in these increases for example where in that pathway from the sunlight hitting the canopy to producing seed where this occurs.
but they can penetrate the roots of banana plants by the thousands. Once infected these plants absorb less water
Lesions in the roots also make the plant more susceptible to other diseases. Eventually the roots begin to rot.
In the final stage of the disease the plant topples over its fruit bunch inexorably lost.
It affects the crop cultivar the variety of seed planted the amount and type of fertilizer required
If there is more vegetation there is more transpiration which means that moisture is being drawn from the soil in the root zone of the plants he says.
Vegetation cover is estimated using the Moderate Resolution Imaging Spectroradiometer (MODIS) scientific instrument launched into Earth orbit by NASA in 1999 on board Terra (EOS AM) and in 2002 on board the Aqua (EOS PM) satellites.
Next a soil moisture profile is developed with the principle of maximum entropy model (POME) which uses prior specific data over a set of trial probabilities to determine which is the most likely outcome.
The model encompasses all inputs into the crop including weather plant spacing cultivar fertilizer soil type and fertility and others.
and industry with the aim of conserving bee populations and protecting and promoting wild flower and crop pollination.
In fight against parasites, Barberry sacrifices seeds depending on survival chanceplants appear to be able to make complex decisions.
and the University of GÃ ttingen have concluded from their investigations on Barberry (Berberis vulgaris) which is able to abort its own seeds to prevent parasite infestation.
The European barberry or simply Barberry (Berberis vulgaris) is a species of shrub distributed throughout Europe. It is related to the Oregon grape (Mahonia aquifolium) that is native to North america
and that has been spreading through Europe for years. Scientists compared both species to find a marked difference in parasite infestation:
a highly specialized species of tephritid fruit fly whose larvae actually feed on the seeds of the native Barberry was found to have a tenfold higher population density on its new host plant the Oregon grape reports Dr. Harald Auge a biologist at the UFZ.
This led scientists to examine the seeds of the Barberry more closely. Approximately 2000 berries were collected from different regions of Germany examined for signs of piercing
If the larva is able to develop it will often feed on all of the seeds in the berry.
A special characteristic of the Barberry is that each berry usually has two seeds and that the plant is able to stop the development of its seeds in order to save its resources.
This mechanism is employed also to defend it from the tephritid fruit fly. If a seed is infested with the parasite later on the developing larva will feed on both seeds.
If however the plant aborts the infested seed then the parasite in that seed will also die
and the second seed in the berry is saved. When analysing the seeds the scientists came across a surprising discovery:
the seeds of the infested fruits are aborted not always but rather it depends on how many seeds there are in the berries explains Dr. Katrin M. Meyer who analysed the data at the UFZ and currently works at the University of Goettingen.
If the infested fruit contains two seeds then in 75 per cent of cases the plants will abort the infested seeds in order to save the second intact seed.
If however the infested fruit only contains one seed then the plant will only abort the infested seed in 5 per cent of cases.
The data from fieldwork were put into a computer model which resulted in a conclusive picture. Using computer model calculations scientists were able to demonstrate how those plants subjected to stress from parasite infestation reacted very differently from those without stress.
If the Barberry aborts a fruit with only one infested seed then the entire fruit would be lost.
Instead it appears to'speculate'that the larva could die naturally which is a possibility.
Slight chances are better than none at all explains Dr. Hans-Hermann Thulke from the UFZ.
But how does the Barberry know what is in store for it after the tephritid fruit fly has punctured a berry?
It is still unclear as to how the plant processes information and how this complex behaviour was able to develop over the course of evolution.
The Oregon grape that is closely related to the Barberry has been living in Europe for some 200 years with the risk of being infested by the tephritid fruit fly
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