Biología
https://hdl.handle.net/10669/273
2024-03-29T08:01:29ZMapa de aviturismo en la Zona Protectora Río Navarro - Río Sobrero
https://hdl.handle.net/10669/91095
Mapa de aviturismo en la Zona Protectora Río Navarro - Río Sobrero
Mapa del circuito de aviturismo Zona Protectora Río Navarro Río Sombrero, incluye zonas de vida, red hídrica, principales poblados, curvas de nivel y sitios de interés para la observación de aves según resultados del proyecto C2090 CIRCUITO DE AVITURISMO COMO HERRAMIENTA DE DIVERSIFICACIÓN SOCIOECONÓMICA EN LA ZONA PROTECTORA RÍO NAVARRO – RÍO SOMBRERO. 2022-2023.
2023-01-01T00:00:00ZSpecific leaf area (SLA) serves as a proxy to predict total carbon content in understory individuals of the neotropical canopy palm Socratea exorrhiza
https://hdl.handle.net/10669/91004
Specific leaf area (SLA) serves as a proxy to predict total carbon content in understory individuals of the neotropical canopy palm Socratea exorrhiza
Evaluating intraspecifc and ontogenetic variation in SLA is critical to understand how functional traits infuence plant ftness and regeneration strategies. SLA is usually expressed as an average value per species. Its variation across
ontogenetic stages and environmental gradients is poorly known, particularly in palms. I measured SLA in 112 palms of
Socratea exorrhiza in the understory of a tropical rainforest in Costa Rica. Total carbon content sequestered per palm (kg)
was estimated from an allometric equation. I determined the regression between Ln SLA and Ln carbon content, and then
used principal components to summarize the regeneration strategy of S. exorrhiza by examining the allometry of stem length
and diameter, number of fronds, number of stilt roots, stilt root cone height, slenderness ratio, SLA, and carbon content. SLA
predicted total sequestered carbon (slope = −4.33, r
2=0. 52). Smaller values of SLA were associated with increased carbon
content and larger palms. Two components explained 77% of the variation in functional traits. The frst (76%) was dominated
by stem diameter, height, stilt root cone, and carbon content (negatively associated with SLA) and refected palm size; the
second (15%) was dominated by slenderness ratio and number of leaves and refected allocation to growth in height. The
inverse relationship between SLA and sequestered carbon is consistent with the initial shade tolerant, conservative resource
use strategy of S. exorrhiza.
2023-01-01T00:00:00ZReporte de capturas de aves en el páramo del Cerro Buena Vista, Costa Rica
https://hdl.handle.net/10669/90999
Reporte de capturas de aves en el páramo del Cerro Buena Vista, Costa Rica
El objetivo de esta nota es reportar la captura
de 13 especies de aves en el páramo del Cerro
Buena Vista de Febrero del 2017, a Enero del
2018. Ya que la progresión del cambio climático
está avanzando más rápidamente de lo esperado es importante generar los datos necesarios que
sirvan de comparación con estudios futuros a
fin de determinar cómo la biota tropical de alta
montaña responde a este proceso.
El sitio de estudio corresponde al páramo
del Cerro Buena Vista (09º33’N- 83º45’O), 3,380
msnm, cerca del kilómetro 89 de la Carretera
Interamericana Sur. En esta zona existe cierto
grado de intervención ya que muchas áreas de
vegetación se cortan para mantener senderos de
acceso a las antenas del Instituto Costarricense
de Electricidad (ICE). Cada mes durante el
periodo de muestreo colocamos 2-3 redes de
niebla de 12 x 2.5 m durante 2-3 días, las que
se mantuvieron abiertas entre las 07:00 y las
17:00 horas. Las redes se cerraron cuando
se presentaron condiciones lluviosas. Si bien
nuestra investigación principal estaba centrada
en determinar la carga de polen de colibríes,
registramos todas las especies de aves capturadas
en redes.
2019-01-01T00:00:00ZSelfing in epiphytic bromeliads compensates for the limited pollination services provided by nectarivorous bats in a neotropical montane forest
https://hdl.handle.net/10669/90993
Selfing in epiphytic bromeliads compensates for the limited pollination services provided by nectarivorous bats in a neotropical montane forest
Plants with specialized pollination systems frequently exhibit adaptations for self-pollination, and this contradictory situation has been explained in terms of the reproductive assurance function of selfing. In the Neotropics, several plant lineages rely on specialized vertebrate pollinators for sexual reproduction, including the highly diverse Bromeliaceae family, which also displays a propensity for selfing. Thus far, the scarce evidence on the role of selfing in bromeliads and in other neotropical plant groups is inconclusive. To provide insights into the evolution and persistence of self-fertilization in the breeding systems of Bromeliaceae, we studied four sympatric epiphytic species from the genus Werauhia (Tillandsioideae) in Costa Rica. We documented their floral biology, pollination ecology, and breeding systems. We estimated the contribution of selfing by comparing the reproductive success between emasculated flowers requiring pollinator visits and unmanipulated flowers capable of selfing and exposed to open pollination across two flowering seasons. The studied species displayed specialized pollination by nectar-feeding bats as well as a high selfing ability (autofertility index values > 0.53), which was attained by a delayed selfing mechanism. Fruit set from natural cross-pollination was low (<26% in both years) and suggested limited pollinator visitation. In line with this, we found a very low bat visitation to flowers using video-camera recording, from 0 to 0.24 visits per plant per night. On the contrary, the contribution of selfing was comparatively significant since 54-80% of the fruit set from unmanipulated flowers can be attributed to autonomous self-pollination. We concluded that inadequate cross-pollination services diminished the reproductive success of the studied Werauhia, which was compensated for by a delayed selfing mechanism. The low negative effects of inbreeding on seed set and germination likely reinforce the persistence of selfing in this bromeliad group. These results suggest that selfing in bat-pollinated bromeliads may have evolved as a response to pollinator limitation.
2024-02-01T00:00:00Z