Phenology and Stem Diameter Increment Seasonality in a Costa Rican Wet Tropical Forest (original) (raw)
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Forest Ecology and Management, 1999
Studies of growth rates of trees in managed neotropical forests have rarely employed complete botanical identi®cation of all species, while published information for Central American lowland rain forests largely concerns forests free of recent disturbance. We studied diameter increments of trees in a managed Costa Rican rain forest. The Pentaclethra macrolobadominated forest was located on low hills with Ultisols in Holdridge's Tropical Wet Forest life zone. The 540 m  540 m (29.2 ha) experimental area was lightly logged during 1989±1990. The 180 m  180 m (3.24 ha) experimental plots comprised a 100 m  100 m (1.0 ha) central permanent sample plot (PSP) with a 40-m wide buffer strip. Post-harvest silvicultural treatments were liberation/re®nement (in 1991) and shelterwood (in 1992), applied under a complete randomized block design with three replicates, using logged but untreated plots as controls. All live trees !10 cm DBH in the PSPs, were identi®ed to species; data reported are for 1993±1996. Cluster analysis was used to group species on the basis of the median and quartiles of their diameter increment distributions, separating data by silvicultural treatments; ®ve diameter increment groups were established and subdivided on the basis of the adult height of each species (four categories), giving 17 species groups in the ®nal classi®cation. Adult height and silvicultural treatment made a signi®cant contribution to growth rate variation. Median annual increments of the slowest-growing species groups, which featured many under-and middle story species, were ca. 1 mm; those for the fastest growing species, which were mainly canopy and emergents, were ca. 16 mm. All species in the groups of very fast growth were pioneers, whether short or long-lived, though many other pioneer species did not show fast growth. The proportions of species found in groups of moderate, fast or very fast growth were greater in the silviculturally treated plots than in the controls, and one complete diameter increment group, of fast growth, was only represented in the treated plots. Crown form, crown illumination and presence of lianas in the crown, showed signi®cant correlations with diameter increments, though the importance of these latter two variables varied with silvicultural treatment. The very fast growth groups differed from the others in having higher proportions of trees with well-formed, well-illuminated crowns and an irregular diameter distribution with relatively few individuals in the smallest DBH class. Comparison with data from other neotropical forest sites shows that long-lived pioneers such as Vochysia ferruginea and Jacaranda copaia grow fast or very fast at all sites, while non-commercial canopy and emergent species of Chrysobalanaceae and Sapotaceae appear to be uniformly slow-growing. Growth data for the majority of species are, however, published for the ®rst time. #
Phenology and radial stem growth periodicity in evergreen subtropical rainforest trees
IAWA Journal, 2010
A close relationship between leafing, flowering, fruiting and radial growth has been conjectured to occur in tropical and subtropical rainforest trees. Radial stem growth, in particular, has been associated with the activity of the two secondary meristems, the vascular cambium and, to a lesser degree, the phellogen. In tropical trees vascular cambium activity may occur either virtually year-round, or it may be restricted to a short season. Phellogen and vascular cambium activities may or may not correspond to each other. In subtropical environments, even evergreens may demonstrate seasonal phenology in leaf initiation, flowering and seed set. In the present study, phenological events were analyzed in the evergreen species Aphananthe monoica, Pleuranthodendron lindenii and Psychotria costivenia. A correlation analysis showed that more than half of the variation is shared by phenological event variables (leafing, flowering and fruiting) and radial growth variables (vascular cambium an...
Trees, 2012
The aim of the present study was to investigate differences in stem radial increment between the savanna and forest ecotypes of Plathymenia reticulata at an ecotonal site. It was hypothesised that even under similar climate conditions, the savanna and forest ecotypes exhibit differences in radial growth, phenology, and water status because of differences in wood density. Stem radial increment, phenology, and water potential were evaluated monthly. The radial increment was positively related to precipitation and displayed no increment (or decrement) in months with low rainfall. A negative relationship was observed between radial growth and wood density, with the forest ecotype exhibiting a higher radial increment than the savanna ecotype. Midday water potential (W MD ) was also negatively related to wood density. Compared to the forest ecotype, the savanna ecotype displayed lower values of W MD during the dry season and started leaf senescence earlier at the beginning of the dry season. Leaf fall improved water status, resulting in leaf flushing even without a significant increase in rainfall. Radial growth significantly increased only after the crown leaf cover was completed. The results confirmed the importance of wood density in the differential responses of ecotypes in relation to growth, water status, and phenology.
Oecologia, 2010
Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees—those that have not attained the canopy—are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests.
Forests, 2018
The timing, duration, magnitude and synchronicity of plant life cycles are fundamental aspects of community dynamics and ecosystem functioning, and information on phenodynamics is essential for accurate vegetation classification and modeling. Here, we recorded the vegetative and reproductive phenodynamics of 479 individuals belonging to 182 tree species monthly over two years in a lowland Atlantic Forest in southeastern Brazil, and assessed the relationship between local climatic conditions and the occurrence and intensity of phenophases. We found a constant but low intensity of occurrence of both leaf fall and leaf flush with respect to canopy cover, resulting in an evergreen cover throughout the year. The timing of the reproductive phenophases was irregular between the two years of observation, and their amplitude was low. In addition, flowering and fruiting phenograms of activity, intensity and intensity corrected by the basal area did not overlap. These results suggest that a combination of phenological records and community-structure parameters allows for the obtainment of more accurate estimates of resource availability over time. We found that differences in growing degree-days (GDD), photoperiod and precipitation over time were related to temporal variation in leaf fall, leaf flush and flowering, with a large consistency in responses across tree species in this lowland Atlantic Forest. Moreover, there was only a weak relationship between climatic conditions and the dynamics of fruit formation and ripening, which were more strongly related to flowering phenodynamics, which is suggestive of indirect effects of climatic conditions on fruiting. Finally, the association we found between the number of days with precipitation and leaf fall dynamics agrees with the view that the greater potential for extreme events may impair plant growth in tropical forests. This reinforces the growing concerns regarding the risk of ecological collapse of tropical forests due to fragmentation and global climate change.
Biotropica, 2010
We compared the functional type composition of trees Z10 cm dbh in eight secondary forest monitoring plots with logged and unlogged mature forest plots in lowland wet forests of Northeastern Costa Rica. Five plant functional types were delimited based on diameter growth rates and canopy height of 293 tree species. Mature forests had significantly higher relative abundance of understory trees and slow-growing canopy/emergent trees, but lower relative abundance of fast-growing canopy/emergent trees than secondary forests. Fast-growing subcanopy and canopy trees reached peak densities early in succession. Density of fast-growing canopy/ emergent trees increased during the first 20 yr of succession, whereas basal area continued to increase beyond 40 yr. We also assigned canopy tree species to one of three colonization groups, based on the presence of seedlings, saplings, and trees in four secondary forest plots. Among 93 species evaluated, 68 percent were classified as regenerating pioneers (both trees and regeneration present), whereas only 6 percent were classified as nonregenerating pioneers (trees only) and 26 percent as forest colonizers (regeneration only). Slow-growing trees composed 72 percent of the seedling and sapling regeneration for forest colonizers, whereas fast-growing trees composed 63 percent of the seedlings and saplings of regenerating pioneers. Tree stature and growth rates capture much of the functional variation that appears to drive successional dynamics. Results further suggest strong linkages between functional types defined based on adult height and growth rates of large trees and abundance of seedling and sapling regeneration during secondary succession.
Austral Ecology, 2009
We investigated the local environmental controls on daily fluctuations of cumulative radial increment and cambial hydration of three dominant, evergreen tree species from montane, Coastal rainforests of Chiloé Island, Chile (42°22′ S). During 2 years (1997-1998 and 1998-1999) we recorded hourly cumulative radial increments using electronic band dendrometers in the long-lived conifer Fitzroya cupressoides (Cupressaceae), the evergreen broad-leaved Nothofagus nitida (Nothofagaceae), and the narrow-leaved conifer Podocarpus nubigena (Podocarpaceae). We also measured soil and cambial tissue hydration using capacitance sensors, together with air and soil temperature and rainfall during the period of the study. In addition, we collected cores of these tree species to evaluate how dendrometer measurements reflect annual tree ring width. One-year long daily time series of cumulative radial increments suggests that radial growth of Fitzroya cupressoides was initiated slowly in early spring, with a maximum in early summer. Multiple regressions showed positive relations between daily precipitation and radial index (i.e. the difference in cumulative radial increment of two consecutive days) in the three species. According to path analysis there was a significant direct effect of changes in tree hydration on radial index of the three focal species. In emergent, pioneer species such as Nothofagus and Fitzroya, radial index was negatively affected by changes in maximum air temperature and photosynthetically active radiation, probably because of high evapotranspiration demand on warm sunny days. The shade-tolerant species Podocarpus nubigena was positively affected by photosynthetically active radiation. Our diel scale findings support the use of tree ring widths for reconstructing past climate in these southern temperate forests and provide evidence that rainforest trees may be highly sensitive to future declines in rainfall and temperature increases during summer. Fig. 2. Daily time series (1 December 1998 to 31 May 1999) of cumulative radial increment (mm) of Fitzroya cupressoides (n = 9 trees): trees with slight shrinking-swelling cycles during summer (a) and trees with strong shrinking-swelling cycles during summer (b), average radial index (c), average tree and soil hydration and precipitation (d) and average air and soil temperatures (e). 264 C. A. PÉREZ ET AL.
With data from 15 species in eight families of tropical dry forest trees, we provide evidence of coordination between the stem and leaf economic spectra. Species with low-density, flexible, breakable, hydraulically efficient but cavitationally vulnerable wood shed their leaves rapidly in response to drought and had low leaf mass per area and dry mass content. In contrast, species with the opposite xylem syndrome shed their costlier but more drought-resistant leaves late in the dry season. Our results explain variation in the timing of leaf shedding in tropical dry forests: selection eliminates combinations such as lowproductivity leaves atop highly vulnerable xylem or water-greedy leaves supplied by xylem of low conductive efficiency. Across biomes, rather than a fundamental trade-off underlying a single axis of trait covariation, the relationship between leaf and stem economics is likely to occupy a wide space in which multiple combinations are possible.
LEAF DEMOGRAPHY AND PHENOLOGY IN AMAZONIAN RAIN FOREST: A CENSUS OF 40 000 LEAVES OF 23 TREE SPECIES
Ecological Monographs, 2004
The periodicity, synchrony, and causes of variability in the demography of tree leaves in ecosystems with relatively aseasonal climates, such as tropical rain forests, is still poorly understood. To address this issue, we surveyed the timing of birth and death of Ͼ40 000 leaves of 1445 individuals of 23 evergreen rain forest species in several late primary and early secondary successional plant communities at San Carlos de Rio Negro, Venezuela, in the northern Amazon basin. In all species, the mortality rate generally increased with leaf age. However, in many species, deceleration of death rates with extreme leaf age was noted. In general, for each species, the age structure of leaf populations and the frequency distribution of leaf life span were broad. Species differed substantially in their leaf demography. Measured in their native habitats, seven species common to disturbed open sites had shorter median life spans (0.7 yr) than five species common to open but infertile Bana primary communities (1.9 yr average) or six species common to two tall primary forest communities (Tierra Firme and Caatinga), when measured in high-light conditions in the canopy (2.0 yr average).