Semi-deciduous

About: Semi-deciduous is a research topic. Over the lifetime, 135 publications have been published within this topic receiving 5004 citations.

Phenology and Other Characteristics of Tropical Semi-Deciduous Forest in North-Western Costa Rica

Abstract: During the rainy season the semi-deciduous forest in tropical north-western Costa Rica bears a close rememblance to deciduous forests of temperate eastern U.S.A. and central Europe in their summer aspect. This physiognomic resemblance is ecologically striking since the former temperature varies but little through the year with rainfall differing markedly, whereas in the latter precipitation is abundant at all seasons but temperatures are strongly contrasted between summer and winter. During a year's residence in the Costa Rican forest, records were made of tree growth, flowering, and fruiting with the objective of characterizing such features of the vegetation more closely than has yet been done, and where feasible drawing comparisons with the temperate zone forest.

Ecophysiological traits of deciduous and evergreen woody species in the seasonally dry tropics

Abstract: Seasonally dry tropical ecosystems occur in the Americas, Africa, India and Australia They sustain large human populations, determine regional climate, are sites of biological and cultural conservation, and have significant economic value Evergreen, deciduous and semi- and brevideciduous trees frequently co-occur Recent research reveals how these various phenological groups respond to changes in soil and atmospheric water content Cost–benefit analyses of evergreen and deciduous species show how leaves of deciduous species live fast and die young, whereas leaves of evergreen species live slowly but for longer

Palatability of woody plants to browsing ruminants in a south african savanna

Abstract: We recorded food selection by free-ranging kudus (Tragelaphus strepsiceros), impalas (Aepyceros melampus), and domestic goats in the Nylsvley Nature Reserve in South Africa. The predominant vegetation is a deciduous wooded savanna growing on infertile sandy soils; patches of Acacia savanna occur on the more fertile sites of former human settlements. Woody species fall into two basic categories of acceptability to the animals: (1) species favored year-round; and (2) species generally rejected, except during certain periods. Among the latter, some species increase in acceptability during the dry season; others are favored temporarily while new leaves predominate. Some species remain low in acceptability year-round. We propose a palatability classification of woody species, considering features of leaf retention (deciduous vs. evergreen) and spinescence, as well as seasonal variations in acceptability. Estimated annual foliage losses to browsing ungulates were 1-3% for unpalatable deciduous species, compared with 10-30% for most palatable unarmed deciduous and evergreen species. Unpalatable deciduous species dominate the woody foliage biomass on the infertile soils, while palatable but spinescent species make up most of the leaf biomass of trees and shrubs on the more fertile sites. These patterns seem widely typical of African savanna. Plants known to have chemical defenses against vertebrate herbivory are prominent on nutrient-deficient soils, while those with structural defenses are prominent on fertile soils.

Modification of Vegetative Phenology in a Tropical Semi-deciduous Forest by Abnormal Drought and Rain1

Abstract: The control of vegetative phenology in tropical trees is not well understood. In dry forest trees, leaf abscission may be enhanced by advanced leaf age, increasing water stress, or declining photoperiod. Normally, it is impossible to dissect the effects of each of these variables because most leaves are shed during the early dry season when day length is near its minimum and leaves are relatively old. The 1997 El-Nino Southern Oscillation caused a ten-week long, severe abnormal drought from June to August in the semi-deciduous forests of Guanacaste, Costa Rica. We monitored the effect of this drought on phenology and water status of trees with young leaves and compared modifications of phenology in trees of different functional types with the pattern observed during the regular dry season. Although deciduous trees at dry sites were severely water stressed (ΨSTEM < −7MPa) and their mesic leaves remained wilted for more than two months, these and all other trees retained all leaves during the abnor...

Leaf functional traits of Neotropical savanna trees in relation to seasonal water deficit

Abstract: The seasonal savannas (cerrados) of Central Brazil are characterized by a large diversity of evergreen and deciduous trees, which do not show a clear differentiation in terms of active rooting depth. Irrespective of the depth of the root system, expansion of new foliage in deciduous species occurs at the end of the dry season. In this study, we examined a suite of leaf traits related to C assimilation, water and nutrients (N, P) in five deciduous and six evergreen trees that were among the dominant families of cerrado vegetation. Maximum CO2 assimilation on a mass basis (Amass) was significantly correlated with leaf N and P, and specific leaf area (SLA; leaf area per unit of leaf mass). The highest leaf concentrations of both nutrients were measured in the newly mature leaves of deciduous species at the end of the dry period. The differences in terms of leaf N and P between evergreen and deciduous species decreased during the wet season. Deciduous species also invested less in the production of non-photosynthetic leaf tissues and produced leaves with higher SLA and maintained higher water use efficiency. Thus, deciduous species compensated for their shorter leaf payback period by maintaining higher potential payback capacity (higher values of Amass) and lower leaf construction costs (higher SLA). Their short leafless period and the capacity to flush by the end of the dry season may also contribute to offset the longer payback period of evergreen species, although it may involve the higher cost of maintaining a deep-root system or a tight control of plant water balance in the shallow-rooted ones.