By Thembi Borras
We can all breath a collective sigh of relief, the madrones, for the most part, are back and more glorious than ever. Madrones are susceptible to foliar leaf pathogens, the symptoms of which can range from small necrotic leaf spots to the entire leaf dying such as we have seen evolve over the course of the last year. In January of 2006 I reported that the late spring rains in 2005 had created a prime environment, high moisture during a warmer time of the year, for the growth of foliar pathogens including the native foliar pathogen causing the malady. At that time, I thought the consequence would likely be slowed growth, but the madrone would recover.
As time and the spring equinox passed and the madrones showed no signs of improvement, I became less certain that they would make a full recovery and thought it likely that at the very least there would be lasting effects such as part of the tree dying. Finally, spring brought renewal; flawless leaves began emerging three weeks ago and now govern the dead leaves that subtend them.
There are several resources available to address your concerns about tree damage caused by animals, insects and diseases. I recommend the annual reports published by the California Forest Pest Council entitled "California Forest Pest Conditions". This report summarizes the forest pest activity in California per year by providing information submitted by the aerial survey program, entomologists, pathologists, botanists and other forest health specialists. To view this report go to www.fire.ca.gov, click on Resource Management and Forestry, click on Pest Management under Category Links and click on California Forest Pest Conditions Report.
The California Forest Pest Council also sponsors the Cooperative Forest Pest Detection Survey to which they encourage federal, state, and private land managers and individuals to contribute by submitting pest injury reports and samples. For instructions on collecting and mailing samples and to fill out a Forest Pest Detection Report, go to www.fire.ca.gov, click on Resource Management and Forestry, click on Pest Management under Category Links and click on Forest Pest Detection Report Form.
May 28, 2006
Bishop Pine Health at the Mendocino Coast Botanical Gardens
By Thembi Borras
An ever present reason for the decline of a tree is old age. The age after which trees decline varies with species and site quality. In forestry terms, some identify this age as being synonymous with the culmination of mean annual increment (CMAI), which is defined as the age at which the stand volume production rate is maximized. Although we like to call it the "Golden Years" for ourselves foresters offer the term "senescence" for this stage in the life of a tree.
What got me thinking about senescence was my visit in April to the Mendocino Coast Botanical Gardens to see the bishop pine, which was prompted by one of the volunteers. He wanted to have more information for patrons when they asked about the health of the bishop pine, which he said they often do.
Of the 47 acres that comprise the Mendocino Coast Botanical Gardens, several acres support a relatively even aged overstory of bishop pine, some of which have died and been topped or removed for safety. Several bishop pines display dead brown branches within the living crown, otherwise known as flagging and many of the crowns appear to be thinning.
Typically, the number of years a tree has lived, alone, will not cause flagging or death. Instead age yields a weakened state that invites a myriad of biological agents and when combined with harsh environmental conditions and animal damage may lead to the demise of a tree.
Too much water can also tip the balance. For example, shore pine on the west side of Highway 1 just north of the Albion River Inn started dying several years ago. According to Jack Marshall, Forest Pathologist at the California Department of Forestry and Fire Protection, the mortality agents are the pine engraver beetle and sour sap beetle. The shore pines follow a watercourse, which is likely receiving increased water due to a change in the water drainage pattern.
If the bishop pine at the Mendocino Coast Botanical Gardens will run their course in the next few decades the question becomes how can the next generation be encouraged without the benefit of fire, which bishop pine needs to regenerate. Bishop pine seeds are stored in closed cones until the cones are opened during fire or very hot conditions when large numbers of seeds are released to inhabit the disturbed ground.
A portion of this production was gleaned from the website: http://en.wikipedia.org/wiki/pine.
An ever present reason for the decline of a tree is old age. The age after which trees decline varies with species and site quality. In forestry terms, some identify this age as being synonymous with the culmination of mean annual increment (CMAI), which is defined as the age at which the stand volume production rate is maximized. Although we like to call it the "Golden Years" for ourselves foresters offer the term "senescence" for this stage in the life of a tree.
What got me thinking about senescence was my visit in April to the Mendocino Coast Botanical Gardens to see the bishop pine, which was prompted by one of the volunteers. He wanted to have more information for patrons when they asked about the health of the bishop pine, which he said they often do.
Of the 47 acres that comprise the Mendocino Coast Botanical Gardens, several acres support a relatively even aged overstory of bishop pine, some of which have died and been topped or removed for safety. Several bishop pines display dead brown branches within the living crown, otherwise known as flagging and many of the crowns appear to be thinning.
Typically, the number of years a tree has lived, alone, will not cause flagging or death. Instead age yields a weakened state that invites a myriad of biological agents and when combined with harsh environmental conditions and animal damage may lead to the demise of a tree.
Too much water can also tip the balance. For example, shore pine on the west side of Highway 1 just north of the Albion River Inn started dying several years ago. According to Jack Marshall, Forest Pathologist at the California Department of Forestry and Fire Protection, the mortality agents are the pine engraver beetle and sour sap beetle. The shore pines follow a watercourse, which is likely receiving increased water due to a change in the water drainage pattern.
If the bishop pine at the Mendocino Coast Botanical Gardens will run their course in the next few decades the question becomes how can the next generation be encouraged without the benefit of fire, which bishop pine needs to regenerate. Bishop pine seeds are stored in closed cones until the cones are opened during fire or very hot conditions when large numbers of seeds are released to inhabit the disturbed ground.
A portion of this production was gleaned from the website: http://en.wikipedia.org/wiki/pine.
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