Posts Tagged: vegetation
Thinking about Hiring a Targeted Grazing Contractor? Here are a Few Things You Need to Know!
Targeted grazing using sheep, goats, or cattle (or combinations of two or more species) can be an...
Nearly Half of California’s Vegetation at Risk From Climate Stress - Slashing Emissions to Paris Climate Agreement Targets Could Reduce Impacts 20-30 Percent
Reposted from UC Davis News
As climate change transforms California's landscape in the years to come, coastal habitats appear to be more resilient than many other places in the state. (Getty Images)
Current levels of greenhouse gas emissions are putting nearly half of California's natural vegetation at risk from climate stress, with transformative implications for the state's landscape and the people and animals that depend on it, according to a study led by the University of California, Davis. However, cutting emissions so that global temperatures increase by no more than 2 degrees Celsius (3.2 degrees Fahrenheit) could reduce those impacts by half, with about a quarter of the state's natural vegetation affected.
The study, published in the journal Ecosphere, asks: What are the implications for the state's vegetation under a business-as-usual emissions strategy, where temperatures increase up to 4.5 degrees Celsius by 2100, compared to meeting targets outlined in the Paris climate agreement that limit warming to 2 degrees Celsius?
“At current rates of emissions, about 45-56 percent of all the natural vegetation in the state is at risk, or from 61,190 to 75,866 square miles,” said lead author James Thorne, a research scientist with the Department of Environmental Science and Policy at UC Davis. “If we reduce the rate to Paris accord targets, those numbers are lowered to between 21 and 28 percent of the lands at climatic risk.”
The report notes that this is a conservative estimate because it only examines direct climate exposure. It does not include increased wildfire or insect attacks on forests, which are also intensifying and likely to increase with further warming. These secondary effects are likely to have large impacts, as well, the authors say. For example, during the recent drought, more than 127 million trees died primarily due to beetle outbreaks, and wildfires have consumed extensive amounts of natural vegetation.
68 percent of LA, San Diego regions impacted
The study features maps of the state and shows the climate risk to 30 different vegetation types under different climate scenarios. It projects that at current rates of greenhouse gas emissions, vegetation in southwestern California, the Central Valley and Sierra Nevada mountains becomes more than 50 percent impacted by 2100, including 68 percent of the lands surrounding Los Angeles and San Diego.
“This is the map of where we live,” Thorne said. “The natural landscapes that make up California provide the water, clean air and other natural benefits for all the people who live here. They provide the sanctuary for California's high biodiversity that is globally ranked. This map portrays the level of climate risk to all of those things. In some cases, the transformation may be quite dramatic and visible, as is the case with wildfire and beetle outbreaks. In other cases, it might not be dramatically visible but will have impacts, nevertheless.”
Resilient areas also identified
The study and its maps are being used by state agencies and land managers to make decisions under changing conditions. Commissioned by the California Department of Fish and Wildlife, the data is helping the agency understand not only which parts of the state are vulnerable to climate change, but also which areas are more resilient, such as some coastal areas and parts of northwestern California, so they can ensure they remain resilient.
“In California, we have good information on the vulnerability of fish and wildlife to climate change,” said Whitney Albright, a project manager with the California Department of Fish and Wildlife. “But we were missing this crucial piece of climate risks to underlying habitat. This study helped fill the information gap. We've already started to use its data in our conservation planning efforts.”
The study also provides a risk assessment for policymakers to consider the benefits to California of reaching Paris climate agreement emission targets that limit global warming to 2 degrees Celsius, and the risks to the state of remaining on the current business-as-usual level of emissions and temperature warming.
Co-authoring institutions included the California Department of Fish and Wildlife, Sequoia and Kings Canyon National Parks, and the U.S. Geological Survey.
The study was funded by the U.S. National Park Service and the California Department of Fish and Wildlife.
/h2>/h2>/figcaption>Save the date for the 2nd annual Do No Harm restoration workshop in Davis, CA 11/15/16!
Please save the date for the 2nd annual Do No Harm workshop focusing on 'Considerations for the use...
DIY 'Recycle Strap Hoe'
This is from the Salinas Valley Agriculture Blog. The video is a must-see--I give it FIVE stars...
Dr. Eric Brennan with a Recycle Strap Hoe
Organic Herbicides: do they work?
In recent years, several organic herbicide products have appeared on the market. These include Weed Pharm (20% acetic acid), C-Cide (5% citric acid), GreenMatch (55% d-limonene), Matratec (50% clove oil), WeedZap (45% clove oil + 45% cinnamon oil), and GreenMatch EX (50% lemongrass oil), among others. These products are all contact-type herbicides and will damage any green vegetation they contact, though they are safe as directed sprays against woody stems and trunks. These herbicides kill weeds that have emerged, but have no residual activity on those emerging subsequently. Additionally, these herbicides can burn back the tops of perennial weeds, but perennial weeds recover quickly.
These products are effective in controlling weeds when the weeds are small and the environmental conditions are optimum. In a recent study, we found that weeds in the cotyledon or first true leaf stage were much easier to control than older weeds. Broadleaf weeds were also found to be easier to control than grasses, possibly due to the location of the growing point (at or below the soil surface for grasses), or the orientation of the leaves (horizontal for most broadleaf weeds).
Organic herbicides only kill contacted tissue; thus, good coverage is essential. In test comparing various spray volumes and product concentrations, we found that high concentrations at low spray volumes (20% concentration in 35 gallons per acre) were less effective than lower concentrations at high spray volumes (10% concentration in 70 gallons per acre). Applying these materials through a green sprayer (only living plants are treated), can reduce the amount of material and the overall cost
http://www.ntechindustries.com/weedseeker-home.html
Adding an organically acceptable adjuvant has resulted in improved control. Among the organic adjuvants tested thus far, Natural wet, Nu Film P, Nu Film 17, and Silwet ECO spreader have performed the best. The Silwet ECO spreader is an organic silicone adjuvant which works very well on most broadleaf weeds, but tends to roll off of grass weeds. The Natural wet, Nu Film 17 and Nu Film P work well for both broadleaf and grass weeds. Although the recommended rates of these adjuvants is 0.25 % v/v, we have found that increasing the adjuvant concentration up to 1% v/v often leads to improved weed control, possibly due to better coverage. Work continues in this area, as manufacturers continue to develop more organic adjuvants. Because organic herbicides lack residual activity, repeat applications will be needed to control new flushes of weeds.
Temperature and sunlight have both been suggested as factors affecting organic herbicide efficacy. In several field studies, we have observed that organic herbicides work better when temperatures are above 75F. Weed Pharm (acetic acid) is the exception, working well at temperatures as low as 55F. Sunlight has also been suggested as an important factor for effective weed control. Anecdotal reports indicate that control is better in full sunlight. However, in a greenhouse test using shade cloth to block 70% of the light, it was found that weed control with WeedZap improved in shaded conditions. The greenhouse temperature was around 80F. It may be that under warm temperatures, sunlight is less of a factor.
Organic herbicides are expensive at this time and may not be affordable for commercial crop production. Because these materials lack residual activity, repeat applications will be needed to control perennial weeds or new flushes of weed seedlings. Finally, approval by one's organic certifier should also be checked in advance as use of such alternative herbicides is not cleared by all agencies.
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