Climate Change Impacts on Trees
Public perceptions of climate change may differ from yours and mine. Arborists know all too well the reality of climate change. We work outdoors every day, and we see the changing weather patterns and their effect on trees and shrubs in the landscape. It is imperative that we take note of these changes. They will influence the advice we give our clients and the plant healthcare we provide.
Climate change isn’t going away, at least in our lifetimes and global temperatures will continue to rise 2-7.2 degrees Fahrenheit in the 21st century. It is estimated that we will see a 22% increase in the frequency of El Nino and La Nina events and/or changes to the jet stream. Google these phenomena for an explanation of the changes they tend to bring in our weather patterns across the United States. We have seen some of the warmest temperatures on record during the past decade. Environmental disasters have been on the increase.
What does this mean? Many people expect to see or experience hotter summers and warmer winters. The experts tell us something quite different. We are told to expect extremes!
For example, some regions will experience more frequent and heavier rainfall events. Others will see hotter and drier summers. Colder winter temperatures have extended deeper into the south and east.
Have you contemplated those changes and what vulnerabilities they might have on the plants we collectively manage?
Warmer winter temperatures could mean:
Disruption to plant hardiness development and dormancy phases.
Earlier springs, resulting in early bud development, making those developing buds susceptible to late spring freeze damage (flower loss and lack of fruit set).
More frequent ice storms and tree damage.
An increase in damaging insect populations, due to a lack of extreme cold temperatures, which moderate population cycles.
Winter chill requirements may not be met for many species, especially detrimental for fruit tree production.
Rapid cooling, following an unseasonably warm day, resulting in tissue death.
Changes in phenology can adversely affect pollination success and maple syrup flow.
Occasional colder winter temperature extremes could mean:
Decreased survival rate of some damaging insect pest populations, as well as beneficial insects.
Winter kill or dieback of plants used inappropriately in the wrong hardiness zone.
More frequent and heavier rainfall events could mean:
Disrupted growth due to increased flooding and saturated soils.
Increased incidence of disease pathogens.
Stronger storms and damaging wind events.
Storms of quicker succession.
Damaging change in water cycles.
Warmer, drier summers could mean:
Severe drought and co-occurring drought conditions.
Nutrient deficiencies.
Opportunistic insect and disease pest infestations due to plant stress.
Environmental/ecological stress.
Forest fires.
Overall changes affecting the rhizosphere and soil ecology.
Promotion of invasive species.
Additional generation of insect pests per year.
Ultimately, all the above will influence species range, regeneration rates and carbon loss from the soil.
When diagnosing and explaining tree issues to our clients, things may not be so clear. If we are only seeing an expression of symptoms, in the absence of signs, we must look back at local weather conditions to piece together a plausible scenario to explain a tree’s demise.
I have been downloading (National Weather Service) NOAA online weather data for my area for over a decade now. I find these preliminary monthly climate data reports to be quite helpful in my diagnostic process.
Thus, is the changing world we live in. How will you be prepared?