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31 01, 2023

April Showers Bring May Flowers — Or Do They?

2023-02-02T07:23:43-08:00Categories: Blog, Climate, Nora Harlow|Tags: , |

If it seems that some of your trees or shrubs are leafing out or flowering early these days, it may be so. One of the most commonly observed effects of global warming is early onset of these usually reliable signs of approaching spring. Ceanothus maritimus ‘Valley Violet’ usually blooms in early spring. The species is native to coastal bluffs of San Luis Obispo County, California. We know that global warming is not just something that will happen in the future. It’s happening now, has been for decades, and the speed of change is accelerating. According to the

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15 11, 2021

What is a Drought-Tolerant Plant?

2021-11-15T19:38:45-08:00Categories: Blog, Climate, Water|Tags: , , |

Many plants are advertised or described as drought-tolerant, but what, if anything, does that tell us? Drought-tolerant where? Drought-tolerant when? Drought-tolerant if . . . what? By now, with unusually dry weather increasingly common worldwide, most gardeners likely are aware that drought itself may be defined in different ways, depending on one's perspective. Heteromeles arbutifolia (toyon) At the risk of oversimplifying, meteorological drought is lower than normal precipitation. Hydrological drought is lower than normal streamflow or groundwater levels. Agricultural drought is inadequate soil moisture for specific crops. Socioeconomic drought is insufficient water supply to meet demand. Ecological drought is insufficient

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19 05, 2021

Climate Change and Water Supply

2021-05-19T05:29:36-07:00Categories: Blog, Climate, Nora Harlow, Water|Tags: , |

Global temperatures have been rising at least since the middle of the last century, and most projections anticipate that this trend will continue. Effects of warming vary from one region of the world to another but prominently include the likelihood that precipitation will shift from snow to rain in many snow-fed watersheds. It is also likely that snow will melt faster and run off earlier, changing the timing of peak streamflow. Snow is an important, even critical, seasonal water source for many regions with large mountain ranges, including most summer-dry climates. Snowpack accumulates in the mountains in winter when demand

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27 01, 2021

The Many Faces of Summer-Dry

2021-02-16T06:16:26-08:00Categories: Blog, Climate|Tags: , |

Summer-dry climates are not dry climates. They are climates where rain falls mostly in winter. This is not a common arrangement. In most of the world, rain falls in summer or is fairly well distributed year round. Summer-dry climates are usually found on the west coasts of continents in the mid-latitudes where seasonally shifting atmospheric pressure cells block or open up to the jet stream and its storms. The photo above shows a coastal northern California climate in summer. The photo below shows a similar coastal northern California climate in winter or spring. Summer-dry climates vary considerably from one place

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