Ground Truth: A Guide to Tracking Climate Change at Home by Mark L. Hineline

Author:Mark L. Hineline [Hineline, Mark L.]
Language: eng
Format: epub
Tags: nature, General, Environmental Conservation & Protection, Science, Earth Sciences, Meteorology & Climatology
ISBN: 9780226347943
Google: SyCytAEACAAJ
Publisher: University of Chicago Press
Published: 2018-06-21T20:46:26+00:00

Figure 6.3. The reproductive parts of a flower. The stamen is made up of an anther (at the tip) and a filament. The pistil consists of a stigma (at the tip) and a style. The ovary, with ovules within, is also part of the pistil.

Stamens first: these delicate organs are made up of male anthers and aptly named filaments. The anthers are the pollen producers. Look at one, zooming in with your magnifying glass. Count the stamens. Feel the pollen between your fingers. (Never discount the worth of feeling things between your fingers. It’s harder to forget a texture than to remember many visual aspects of shape.) Now, remove the stamens to reveal the pistil fully.

It’s time to get surgical. With the female pistil on a cutting surface of some kind, slice down the center of the pistil to reveal a cross-section of the ovary, with the ovule inside it; the stalklike style; and the stigma. It is here that pollen, deposited on the stigma by wind or breeze, a bumblebee, a bat, a hummingbird, or any number of pollinators, starts its journey through a pollen tube in the style to the ovule, where it fertilizes an egg to form a seed. In self-pollinating plants, such as peas, the pollen can come from within the flower or from an adjacent plant. For a cross-pollinated plant, the pollen must come from another plant.

Flowering plants are dependent on a host of pollinators, both physical (wind) and biological (insects, birds, and mammals, primarily). Here again it is possible that changing phenologies might result in mismatches, favoring some species but leading others to decline and even to extinction. An awareness of pollinators and whether they are present during flowering, and in what numbers, is worthwhile, and such tidbits of information are good inclusions in your notes. Somewhat more difficult to discern but also worth noting, if you suspect them, are changed flowering times for species of plants that share a pollinator.

In vascular plants, fruiting occurs at different times depending on whether the plant grows in a temperate zone or a tropical one. Temperate fruiting occurs in late summer and early autumn in temperate regions, and the time it takes for the phase to complete is about a month and a half (with a lot of variation on either side of that, depending on the size of the fruit and other factors). In tropical regions, different plants fruit at different times of the year.

Some species of flowering (and fruiting) plants do not produce fruits every year. Sometimes they skip several years, and then all the plants of a given species fruit in the same year. The pattern is often unpredictable. Botanists call this masting, and they are at something of a loss to explain it. Are there cues that tell the plants to skip a year? Or is it an absence of cues? One problem with learning more about masting is that it’s a little like Frederic in the Pirates of Penzance, who would be

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