Tropical dry forests (TDFs) present strong seasonal greenness signals ideal for tracking phenology and primary productivity using remote sensing techniques. The tightly synchronized relationship these ecosystems have with water availability offer a valuable natural experiment for observing the complex interactions between the atmosphere and the biosphere in the tropics. To investigate how well the MODIS vegetation indices (normalized difference vegetation index (NDVI) and the enhanced vegetation index (EVI)) represented the phenology of different successional stages of naturally regenerating TDFs, within a widely conserved forest fragment in the semi-arid southeast of Brazil, we installed several canopy towers with radiometric sensors to produce high temporal resolution near-surface vegetation greenness indices. Direct comparison of several years of ground measurements with a combined Aqua/Terra 8 day satellite product showed similar broad temporal trends, but MODIS often suffered from cloud contamination during the onset of the growing season and occasionally during the peak growing season. The strength of the in-situ and MODIS linear relationship was greater for NDVI than for EVI across sites but varied with forest stand age. Furthermore, we describe the onset dates and duration of canopy development phases for three years of in-situ monitoring. A seasonality analysis revealed significant discrepancies between tower and MODIS phenology transitions dates, with up to five weeks differences in growing season length estimation. Our results indicate that 8 and 16 day MODIS satellite vegetation monitoring products are suitable for tracking general patterns of tropical dry forest phenology in this region but are not temporally sufficient to characterize inter-annual differences in phenology phase onset dates or changes in productivity due to mid-season droughts. Such rapid transitions in canopy greenness are important indicators of climate change sensitivity of these already endangered forest ecosystems and should be further monitored using both ground and satellite approaches.

The fields of tropical biology and conservation face significant transformations due to rapid technological developments in remote sensing. Other fields (e.g. Archeology) are experiencing this momentous change even more rapidly. In this article, we review some of the challenges that the fields of tropical biology and conservation face during the first quarter of the twenty‐first century from the perspective of various remote sensing technologies, and discuss the transformations that they may bring to these disciplines. In addition, we review two emerging technologies driving paradigm changes in the nexus of ecology, remote sensing, and analytics: near‐surface remote sensing and Wireless Sensor Networks. These two technologies, arising from the eScience paradigm, offer unique opportunities to integrate field observations at hyper‐temporal and spatial resolutions that were not possible as recently as 5 years ago.

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Abstract. Many aspects of barnacle body form are known to be developmentally plastic. Perhaps the most striking examples of such plasticity occur in their feeding legs and unusually long penises, the sizes and shapes of which can change dramatically and adaptively with changes in conspecific density and local water flow conditions. However, whether variation in overall appendage form is mirrored by structural responses in cuticle and muscle is not known. In order to determine how structural variation underlies phenotypic plasticity in barnacle appendages, we examined barnacles occurring at low and high population densities from one wave-protected and one wave-exposed site. We used histological sectioning and fluorescence microscopy of feeding legs and penises to compare cuticle thickness, muscle thickness, and muscle organization, and artificial penis inflation to compare penis extensibility. We observed striking differences in cuticle thickness, muscle thickness, and muscle organization between sites that differed in water velocity, but we found no clear differences associated with variation in conspecific density. Penis extensibility also did not differ consistently between sites. These results are consistent with an adaptive explanation for much of the remarkable and complex variation in barnacle feeding leg and penis morphology among sites that differ in water velocity.Additional key words: Balanus glandula, cirri, wave exposure Rocky shores are among the most extreme and variable hydrodynamic environments on earth. On wave-exposed shores, the maximum velocity of breaking waves can exceed 25 m s À1, while in nearby protected bays, water velocity may be two orders of magnitude slower, never exceeding 10 cm s À1 (Denny 1988;Denny et al. 2003). Adding to this extreme spatial variability, water velocity at any one place can change dramatically as waves break and recede, and it may also vary significantly throughout the year due to the frequency and severity of storm events (Denny 1988). Surprisingly, despite this widespread variation in water velocity over space and time, a diverse assemblage of plants and animals thrives under these extreme conditions.Intertidal barnacles are one particularly successful group that attains large population sizes on rocky shores worldwide. These small sessile crustaceans are filter feeders that use six pairs of modified biramous thoracic legs, called cirri, to capture particles from the surrounding water. In most acorn barnacles, the last three pairs of cirri align to form a fan-like structure that is extended into the water column, while the first three pairs of cirri are used to filter smaller particles and to clean larger particles from the extended cirri (Anderson 1994). Barnacles extend these feeding legs by increasing hydrostatic pressure generated within a closed circulatory system, and retract them with a bundle of striated muscle fibers that runs from the base to the tip of each ramus (Anderson 1994). However, filter feeding poses a challenge to many intertidal barnacles...

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