Title page for ETD etd-20020109-144734

Type of Document

Master's Thesis

Author

Borkhataria, Rena Rebecca,

URN

etd-20020109-144734

Title

Ecological and Political Implications of Conversion from Shade to Sun Coffee in Puerto Rico

Degree

Master of Science

Graduate Program

Zoology

Advisory Committee

Advisor Name	Title
Jaime Collazo	Chair
Harold Heatwole	Member
Marcia Gumpertz	Member
Martha Groom	Member
Robert Rice	Member

Keywords

No Keywords Found

Date of Defense

2001-10-22

Availability

unrestricted

Abstract

Borkhataria, Rena Rebecca. Ecological and Political Implications of Conversion from
Shade to Sun Coffee in Puerto Rico. (Under the direction of Jaime Collazo.)
Recent studies have shown that biodiversity is greater in shaded plantations than
in sun coffee plantations, yet many farmers are converting to sun coffee varieties to
increase short-term yields or to gain access to economic incentives. Through conversion,
ecosystem complexity may be reduced and ecological services rendered by inhabitants
may be lost. I attempted to quantify differences in abundances and diversity of predators
in sun and shade coffee plantations in Puerto Rico and to gain insight into the ecological
services they might provide. I also interviewed coffee farmers to determine the factors
influencing conversion to sun coffee in Puerto Rico and to examine their attitudes toward
the conservation of wildlife.
Avian abundances were significantly higher in shaded coffee than in sun (p =
0.01) as were the number of species (p = 0.09). Avian species that were significantly
more abundant in shaded coffee tended to be insectivorous, whereas those in sun coffee
were granivorous. Lizard abundances (all species combined) did not differ significantly
between plantations types, but Anolis stratulus was more abundant in sun plantations and
A. gundlachi and A. evermanni were present only in shaded plantations. Insect
abundances (all species combined) were significantly higher in shaded coffee (p = 0.02).
I used exclosures in a shaded coffee plantation to examine the effects of
vertebrate predators on the arthropods associated with coffee, in particular the coffee leaf
miner (Leucoptera coffeela) and the flatid planthopper Petrusa epilepsis, in a shaded
coffee plantation in Puerto Rico. Treatments included exclusion of birds, lizards, birds
and lizards, and no exclusion. I found that birds had a significant effect on the abundance
of Petrusa epilepsis and on insects > 5 mm in length. Combined insect species
abundance as well as abundance of insects 2-5 mm and 5-10 mm varied significantly by
treatment and removal of both birds and lizards had a larger effect than the removal of
either taxa alone. Vertebrate predators exerted little influence over the coffee leaf miner,
nor did they appear to appear with the leaf miner?s natural enemies, a complex of
parasitoid wasps.
In the survey of 100 coffee farmers, I found that sun coffee was substantially
more prevalent than shaded coffee, both in number of farms and in land area devoted to
its production. The average sun coffee plantation was significantly larger than the
average shaded plantation (p = 0.02). Reasons for conversion from shade to sun coffee
included higher yields, recommendations by agronomists, and incentives from the
government.
Farmers placed high conservation value on species that are rare or provide
services to humans. Vertebrate insectivores were more diverse and abundant in shaded
coffee and may provide a service to farmers by depressing total insect numbers and
preventing outbreaks of the planthopper Petrusa epilepsis. Furthermore, they did not
interfere with parasitism of the coffee leaf miner by parasitoid wasps.
I conclude that governmental incentives for shaded coffee have a high probability
of success, since coffee growers are highly dependent upon assistance from the
government.

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