Individual growth, reproduction and population dynamics of Dioon merolae (Zamiaceae) under different leaf harvest histories in Central Chiapas, Mexico
Leaves of the long-lived Dioon merolae have been harvested intensively for decades (possibly for centuries) for ceremonial purposes by Zoque and mestizo groups inhabiting the Central Depression of Chiapas, Mexico. Over a period of four years, we evaluated vital rates (stem growth, leaf production, reproductive performance, and survival) and projected population growth rates in three populations (250 plants each, divided into eight size classes: new germinants, seedlings, saplings (S1, S2), and adults, A1-A4) with different leaf harvesting histories: non-defoliated by humans for at least 55 years (or very old harvest), defoliated annually until 15 years ago (recovering from harvest), and defoliated annually for at least the past 25 years (currently being harvested intensely). Population structure was affected by leaf harvest history. Stem growth was negatively affected by the annual harvest of leaves in size classes from seedlings up to A4 (ANOVA, P < 0.003); fewer leaves were produced by seedlings, saplings and adults at the annually harvested site (ANOVA, P < 0.027). Survival was high at all sites across all size classes; in the annually harvested site, A4 plants showed a decrease in survival (one dead out of four plants). Sex ratio of adults that produced cones during the four years of study was 61% males to 39% females. At the non-defoliated site, adult classes A2 and A4 produced >80% of the cones; no cones were produced by the A3 and A4 adult size classes at the annually harvested site.
| Main Authors: | , , , , |
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| Format: | Texto biblioteca |
| Language: | eng |
| Subjects: | Dioon merolae, Defoliación, Productos naturales no maderables, Población vegetal, Artfrosur, |
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