Individual study: The effect of stake height and diameter at planting on survival and canopy development of Gliricidia sepium in Pico Bonito National Park, Honduras
Zahawi R. A. (2005) Establishment and growth of living fence species: an overlooked tool for the restoration of degraded areas in the tropics. Restoration Ecology, 13, 92-102
In the tropics there are numerous tree species which can establish vegetatively and which could potentially be used in forest restoration projects. However, often little is known about a particular species establishment ability. This study examined whether greater initial stake height and diameter increased the establishment success and crown development of Gliricidia sepium stakes trials in Honduras, central America, where this species is a common constituent of 'living fences.
Study area: The study was carried out between March 2000 and June 2002 in Pico Bonito National Park, a 100,000 ha mountainous park on the north coast of Honduras. Approximately 80% is a core zone of undisturbed forest. However, the surrounding buffer zone is heavily deforested and populated with numerous villages. In March 2000 three sites (elevation 100–400 m) were chosen within the northern buffer zone:
1) Playitas (PLY), an abandoned pasture initially cleared and burned approximately 25 years ago and seeded with the exotic aggressive forage grasses Urochloa brizantha and Pennisetum purpureum.
2) San Francisco (SFR), a ridge originally native pine forest prior to deforestation more than 30 years ago, since dominated by bracken Pteridium aquilinum , and maintained in a state of arrested succession through repeated fires.
3) Centro Universitario Regional Litoral Atlántida (CRL), an abandoned pasture dominated by a variety of native grasses and forbs, and a few early successional shrubs.
Gliricidia sepium planting & size classes: The study was undertaken at each of the sites to quantify the effect of initial stake height and dbh on survival, crown development and biomass of G.sepium. Treatments were initial stake height (50 and 200 cm) and dbh (1.5–3, 3–4.5, 4.5–6 cm). Planting time differed among sites. PLY was planted in the wet season in mid-July 2001, SFR and CRL at the onset of the dry season in early February 2002. Prior to planting, sites were cleared with machetes. Stakes were planted 1.5 m apart in a complete random factorial design forming a 8 × 11 m grid (n = 8/treatment, n = 48 total/site). Survival and crown diameter data were collected monthly. At the end of the study(June 2002), all growth since planting was harvested, dried, and then weighed to estimate above ground biomass production for each stake size class.
Gliricidia sepium survival & growth: Stake establishment and survival was 100% at both SFR and CRL. Initial stake height and diameter affected survival at PLY. Shorter stakes and those with smaller dbh had significantly lower survival values as compared to larger stakes.
Cover: Final cover values differed significantly with respect to diameter and height. Larger diameter stakes had greater cover development than smaller stakes, and tall stakes had greater cover development than short ones. Larger diameter stakes had greater biomass production than smaller stakes, and tall stakes had greater biomass production than short stakes.
Conclusions: Greater initial stake height and diameter at breast height each resulted in greater crown development for G.sepium.
Note: If using or referring to this published study, please read and quote the original paper. Please do not quote as a conservationevidence.com case as this is for previously unpublished work only. The original paper can be viewed at: http://www.blackwell-synergy.com/journal.asp?ref=1061-2971