Ontogenetic changes in leaf phenology of a canopy species, Elateriospermum tapos (Euphorbiaceae), in a Malaysian rain forest

2002 ◽  
Vol 18 (1) ◽  
pp. 91-105 ◽  
Author(s):  
NORIYUKI OSADA ◽  
HIROSHI TAKEDA ◽  
AKIO FURUKAWA ◽  
MUHAMAD AWANG
Keyword(s):  
Rain Forest ◽  
Meteorological Factors ◽  
Light Availability ◽  
Leaf Phenology ◽  
Leaf Fall ◽  
Ontogenetic Changes ◽  
Mature Trees ◽  
Leaf Production ◽  
Leaf Emergence ◽  
Canopy Species

Leaf phenology was studied in individuals of a canopy species, Elateriospermum tapos (Euphorbiaceae), at various ontogenetic stages, in a Malaysian rain forest. The timing of leaf emergence was not synchronized among sapling individuals, and was not correlated with any meteorological factors of the preceding month. The timing of leaf fall in saplings was positively correlated with net radiation, and maximum and minimum temperature, but negatively correlated with relative humidity the preceding month, although these correlations were weak. The leaf production rate was larger under higher light, but the leaf fall rate was not related to the light regime of the saplings. Thus, leaf production was enhanced by the light availability for each individual, while leaf fall may have been enhanced by drought stress. Non-synchronous leaf production appears to be important for sapling growth, allowing saplings to occupy better-lit space quickly. On the other hand, tall trees showed a clear synchronous leaf-fall pattern, with an annual cycle, and no meteorological factors were correlated with the timing of leaf fall. Mature trees of this species produced flowers simultaneously with new leaves, after shedding their leaves. This suggests that the need to synchronize flowering might be the primary determinant of leaf production phenology in mature individuals.

Litterfall and productivity in a tropical rain forest, Southern Baakundu Forest Reserve, Cameroon

1988 ◽  
Vol 4 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Nicholas C. Songwe ◽  
F. E. Fasehun ◽  
D. U. U. Okali
Keyword(s):  
Relative Humidity ◽  
Linear Regression ◽  
Rain Forest ◽  
Climatic Factors ◽  
Leaf Fall ◽  
Leaf Production ◽  
Forest Reserve ◽  
Weight Losses ◽  
Time Of Year ◽  
Canopy Species

ABSTRACTLitterfall was measured monthly in ten 1 m2 traps in each of two 0.25 ha plots in the rain forest of Southern Bakundu Forest Reserve, Cameroon for 18 months from 1 July 1982 to 31 December 1983. Particular emphasis was placed on measuring species contributions and in relating litterfall to climatic factors; the litterfall data were also used in estimating leaf production. Annual litterfall ranged between 12.9 and 14.1 t ha−1 and was partitioned to leaves (61–66%), branches (23–38%), fruits and flowers (8–12%) and ephiphytes (0.8%). Emergents and top canopy species like Desbordesia glaucescens (evergreen) and Ceiba pentandra (deciduous) contributed more litter than the numerically dominant lower storey species like Cola lepidota and Diospyros spp. Litter fell throughout the year but was greatest during the dry season (November to March); litterfall was thus strongly negatively correlated with environmental moisture variables and could be predicted from its linear regression on time of year, throughfall and relative humidity. By correcting the leaf fall data for leaf weight losses due to grazing and re-translocation, leaf production rates of 10.2 to 11.2 t ha−1 yr−1 were estimated for the forest.

Effect of plant density and light availability on leaf damage in Manilkara bidentata (Sapotaceae)

2000 ◽  
Vol 16 (3) ◽  
pp. 447-464 ◽  
Author(s):  
Pilar Angulo-sandoval ◽  
T. Mitchell Aide
Keyword(s):  
Plant Density ◽  
Spatial Scales ◽  
Light Availability ◽  
Leaf Damage ◽  
Leaf Phenology ◽  
Leaf Miner ◽  
Detectable Effect ◽  
Leaf Production ◽  
Leaf Quality ◽  
Plant Herbivore

Variation in herbivory is often associated with plant density and light environment. The effect of these variables was studied on leaf production and herbivory of Manilkara bidentata in Puerto Rico. The major herbivore of M. bidentata is the leaf miner Acrocercops sp. To determine the effect of plant density, twenty-four 20-m × 20-m plots were established and the densities of saplings, juveniles and adults were determined. Leaf production, herbivory and growth were measured on saplings. Plant density was determined in eight 20-m × 20-m plots surrounding the focal plots. The effect of light was determined by comparing leaf phenology, leaf quality and herbivory in vertical and horizontal profiles. Sapling density in 60-m × 60-m plots was associated with herbivory. In the vertical profile, leaf production was continuous only for the canopy: herbivory increased from the canopy (1.3%) towards the understorey (35.6%). In the horizontal profile leaf production was related to light. Saplings in low light environments had narrow peaks in leaf production compared with saplings in high light environments. Differences in leaf phenology did not result in differences in herbivory possibly because of variation in herbivory among leaves. Although many saplings lost more than 80% of new leaf area, there was no detectable effect on growth. High levels of intra-specific variation in herbivory suggest that to better understand plant/herbivore interactions it is necessary to consider all size classes in a population. It is also important to document these pattern across different spatial scales.

scholarly journals Leafing Patterns and Drivers across Seasonally Dry Tropical Communities

2019 ◽  
Vol 11 (19) ◽  
pp. 2267 ◽  
Author(s):  
Bruna Alberton ◽  
Ricardo da Silva Torres ◽  
Thiago Sanna Freire Silva ◽  
Humberto Rocha ◽  
Magna S. B. Moura ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Light Availability ◽  
Dry Season ◽  
Ecosystem Dynamics ◽  
Day Length ◽  
Leaf Phenology ◽  
Color Channel ◽  
Smooth Functions ◽  
Leaf Production ◽  
Seasonally Dry

Investigating the timing of key phenological events across environments with variable seasonality is crucial to understand the drivers of ecosystem dynamics. Leaf production in the tropics is mainly constrained by water and light availability. Identifying the factors regulating leaf phenology patterns allows efficiently forecasting of climate change impacts. We conducted a novel phenological monitoring study across four Neotropical vegetation sites using leaf phenology time series obtained from digital repeated photographs (phenocameras). Seasonality differed among sites, from very seasonally dry climate in the caatinga dry scrubland with an eight-month long dry season to the less restrictive Cerrado vegetation with a six-month dry season. To unravel the main drivers of leaf phenology and understand how they influence seasonal dynamics (represented by the green color channel (Gcc) vegetation index), we applied Generalized Additive Mixed Models (GAMMs) to estimate the growing seasons, using water deficit and day length as covariates. Our results indicated that plant-water relationships are more important in the caatinga, while light (measured as day-length) was more relevant in explaining leafing patterns in Cerrado communities. Leafing behaviors and predictor-response relationships (distinct smooth functions) were more variable at the less seasonal Cerrado sites, suggesting that different life-forms (grasses, herbs, shrubs, and trees) are capable of overcoming drought through specific phenological strategies and associated functional traits, such as deep root systems in trees.

scholarly journals Tree size as a factor influencing leaf emergence and leaf fall in Acacia nigrescens and Combretum apiculatum in the Kruger National Park

Koedoe ◽  
1989 ◽  
Vol 32 (1) ◽  
Author(s):  
P. Novellie
Keyword(s):  
National Park ◽  
Dry Season ◽  
Kruger National Park ◽  
Tree Size ◽  
Leaf Fall ◽  
Mature Trees ◽  
Leaf Emergence ◽  
Combretum Apiculatum

In Acacia nigrescens and Combretum apiculatum saplings tended to retain leaves over the dry season, whereas the mature trees generally lost most of their leaves. In Acacia nigrescens the production of new leaves over the dry season was more commonly observed in saplings than in mature trees.

scholarly journals Development rate, flower growth and production of Anthurium.

1988 ◽  
Vol 36 (3) ◽  
pp. 219-224
Author(s):  
D. Klapwijk ◽  
H.J.H. van der Spek
Keyword(s):  
Additional Data ◽  
Development Rate ◽  
Abortion Rate ◽  
Flower Buds ◽  
Leaf Production ◽  
Flower Production ◽  
Leaf Emergence ◽  
Flower Growth ◽  
June July

Data on leaf plastochron, flower growth and bud abortion in greenhouse-grown A. andreanum were collected from a commercial nursery throughout the year, and additional data were obtained from growers. The leaf plastochron duration was fairly constant from Mar. until Sep. at an average of 72 days. Around 10 Oct. the duration was more than doubled. It then decreased linearly to 72 days again, resulting in high leaf production around Apr. Leaf plastochron seemed to be related to radiation but daylength was probably not involved, as leaf emergence continued during winter. The longest period between flower emergence and flower harvest was around 21 Dec. and the shortest in June-July. Flower production fluctuated strongly, with a minimum in Mar. and a maximum in the second half of June. This maximum was related to the high leaf production in Feb.-Mar. The low production in Mar. was the result of a high abortion rate (near 100%) of flower buds in Dec. The year-round average abortion rate was about 50%. (Abstract retrieved from CAB Abstracts by CABI’s permission)

La phénologie des arbres caducifoliés en forêt guyanaise (5° de latitude nord) : illustration d'un déterminisme à composantes endogène et exogène

1994 ◽  
Vol 72 (12) ◽  
pp. 1843-1857 ◽  
Author(s):  
Denis Loubry
Keyword(s):  
Key Words ◽  
Tree Species ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
French Guiana ◽  
Dry Season ◽  
Deciduous Tree ◽  
Leaf Fall

The French Guianan forest is an evergreen rain forest that contains approximately 100 deciduous tree species. The taxonomical distribution of the deciduous character is widely spread, and its presence or absence among some taxa, as well as its ancient origin, are arguments in favour of an endogenous origin. Leaf-fall periodicity was studied on a sample of 500 trees during a 2-year period. Periodicity is annual and seasonal. It is not correlated to rainfall and not linked to the occurrence of a dry season. It seems closely correlated to photoperiodical variations, even though those variations are weak (35 min at latitude 5°30′N). However, each tree has its own periodicity for leaves shedding. Therefore, there is a paradox between seasonality and individual periodicity of leaf fall. The existence of this paradox leads us to consider the hypothesis of an integration of endogenous and exogenous components in the determination of leaf-fall periodicity. Key words: deciduousness, French Guiana, phenology, photoperiodism, tree, tropical rain forest.

The effect of leaf phenology of overstory trees on the reproductive success of an understory shrub, Staphylea bumalda DC

2000 ◽  
Vol 78 (6) ◽  
pp. 781-785 ◽  
Author(s):  
Hanako Maeno ◽  
Tsutom Hiura
Keyword(s):  
Reproductive Success ◽  
Resource Limitation ◽  
Fruit Production ◽  
Early Summer ◽  
Leaf Phenology ◽  
Species Variation ◽  
Broad Leaved Forest ◽  
Leaved Forest ◽  
Leafing Date ◽  
Canopy Species

The effects of the leaf phenology of canopy trees on the reproductive success of an entomophilous, self-incompatible shrub, Staphylea bumalda DC. were examined in a deciduous broad-leaved forest in northern Japan. The amount of light reaching a particular understory shrub from spring to early summer was determined by the leafing date of surrounding canopy species. Variation in leafing date of canopy species affected flower and fruit production by the understory shrub. These results suggest that reproductive success of understory shrubs depends in part on the leaf phenology of canopy trees.Key words: phenology, deciduous broad-leaved forest, fruit set, resource limitation.

Canopy Dynamics of Eucalyptus Maculata Hook. I. Distribution and Dynamics of Leaf Populations

1984 ◽  
Vol 32 (4) ◽  
pp. 387 ◽  
Author(s):  
EW Pook
Keyword(s):  
Water Supply ◽  
Leaf Area ◽  
Shoot Growth ◽  
Temperature Limit ◽  
Leaf Fall ◽  
Leaf Production ◽  
Area Index ◽  
Average Size ◽  
Non Destructive

The canopy dynamics of a regenerated 16-year-old stand of pole and sapling E. maculata were studied for 2½ years by repetitive non-destructive measurements in tree crowns accessed from a 20 m high scaffold tower. Average canopy leaf area density over a sample plot of 36 m2 was 0.23 m2 m-3 at a leaf area index of 4.3. Some 75% of leaf area was held in the canopies of overstorey eucalypts above 10 m in height. Average size of leaves increased gradually from top to bottom of tree canopies. Foliage production was usually concentrated in the upper crowns of trees where there was a higher proportion of active shoots, more frequent growth flushes and more rapid turnover of leaves than in lower canopy layers. Leaf area in the upper canopy fluctuated widely but increased in the long term, in mid canopy was more or less maintained and in lowest canopy declined. Crops of developing flower buds present on uppermost branches delayed and/or reduced shoot growth. Foliage production occurred in all months of the year. There was a unimodal annual rhythm of growth rate reaching a maximum in summer and a minimum in winter. Variable water supply, however, influenced production to peak in spring, summer or autumn. No shoot growth occurs in E. maculata at Kioloa when daily mean temperature (averaged for weekly intervals) falls below c. 10½C in winter. An upper temperature limit for growth could not be defined. The species apparently lacks dormancy mechanisms. Shoot growth is 'opportunistic' and occurs whenever environmental conditions are favourable. Patterns of leaf production and leaf fall were variable but peaks showed a general synchrony. Leaf fall, however, tended to lag behind leaf production. Leaves of all ages were shed but main losses were from older cohorts. Some 49% (s.d.±18%) of new leaves were lost while still small or immature, mainly during periods of vigorous shoot growth or low water supply. Browse of immature foliage was light. Normal senescence and leaf fall accounted for almost the entire loss of mature foliage.

Distribution of the eucalypt-defoliating sawfly Perga affinis affinis (Hymenoptera)

1965 ◽  
Vol 13 (4) ◽  
pp. 593 ◽  
Author(s):  
PB Carne
Keyword(s):  
Field Experiments ◽  
Climatic Factors ◽  
Leaf Shape ◽  
Mature Trees ◽  
Leaf Production ◽  
Study Region ◽  
Sawfly Larvae ◽  
Litter Accumulation ◽  
Large Trees ◽  
Individual Trees

The distribution of the sawfly is discussed at several levels, ranging from that within a study region which comprised a substantial proportion of the known range of the insect, to that within the crowns of individual trees. A mosaic of areas was recognized within the region, each characterized by a degree of ecological uniformity and in which saivfly populations maintained relatively high or low levels of abundance during 6 yr of observation. The distribution of the insect is influenced strongly by climatic factors, the rainfall and temperature statistics for the critical period October-March for all areas in which it occurs being closely grouped. Such grouping is even more marked for those areas in which the sawfly was consistently most abundant. The cool wet limit of the sawfly's distribution coincides with that of a favoured host species, but the hot dry limit appears to be determined by the insect's susceptibility to desiccation. Although many naturally occurring and planted eucalypts will support sawfly larvae, persistent infestations were recorded only where one or more of three species grew - Eucalyptus blakelyi, E. camaldulensis, or E. melliodora. The sawfly is an inhabitant of river valley woodland, rarely becoming abundant in other situations and being absent from sclerophyll forest formations. Survival of the insect is greatly influenced by the ease with which it can penetrate into the soil for cocoon formation; it tends to be most abundant in areas of light soil, or where large trees provide a deep litter accumulation. The susceptibility of trees to infestation is influenced by seasonal production of new foliage. Those growing in sites where the water table is high, and whose leaf production is to a large extent independent of rainfall patterns, may be subject to chronic attack. Distribution between trees is affected by their leaf shape and texture, and by their history of previous defoliation. Small trees are particularly prone to attack, and infestation of mature trees is generally an indication of outbreak abundance of the insect. Similarly, marginally favoured species are attacked only when oviposition sites on more favoured trees are virtually saturated. Field experiments indicated that an observed contagious distribution of sawfly eggs in portions of the crowns of individual trees is not the result of overt gregariousness on the part of the females, but results from the attraction of the latter to foliage of certain physical characteristics and position on the tree.

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