Phenological diversity of Maprounea guianensis (Euphorbiaceae) in humid and dry neotropical forests

2020 ◽  
Vol 68 (4) ◽  
pp. 288
Author(s):  
Marília G. M. dos Santos ◽  
Sâmia P. S. Neves ◽  
Ana P. L. do Couto-Santos ◽  
Carlianne O. Cerqueira ◽  
Davi R. Rossatto ◽  
...  
Keyword(s):  
Wiener Index ◽  
Dry Forest ◽  
Leaf Longevity ◽  
Circular Statistics ◽  
Plant Responses ◽  
Neotropical Forests ◽  
Widespread Species ◽  
Leaf Budding ◽  
Individual Trees ◽  
Phenological Diversity

Phenological diversity, seasonality and leaf longevity may affect leaf habits, reflecting plant responses to environmental conditions. Maprounea guianensis Aubl. is a widespread species in Brazil that is associated with different forest types. We investigated how phenological diversity, seasonality and leaf longevity affect leaf habits of its populations growing in humid and dry forests in the Chapada Diamantina mountains. We made monthly observations of leaf budding and fall in 62 individual trees between 2004 and 2012 (84 months), estimating leaf longevity based on phenophase evaluations. We made use of circular statistics, cross correlations and the Shannon–Wiener Index to evaluate our data. There was little variation in rainfall distribution between the study years, although water availability differed at each site. Phenophase seasonality was found to be negatively correlated with rainfall but positively correlated with photoperiod. Low phenological diversity was observed within each site, but not between sites, and leaf longevity was reduced in the dry forest. Although macroclimatic conditions were similar throughout the range of occurrence of M. guianensis in the region, we found that phenological behaviour and leaf longevity differed according to micro-site differences, demonstrating the plasticity of the species, which may favour its occupation of different environments.

Low rates of background canopy-gap disturbance in a seasonally dry forest in the Yucatan Peninsula with a history of fires and hurricanes

2001 ◽  
Vol 17 (6) ◽  
pp. 895-902 ◽  
Author(s):  
MATTHEW B. DICKINSON ◽  
SHARON M. HERMANN ◽  
DENNIS F. WHIGHAM
Keyword(s):  
Canopy Gap ◽  
Dry Forest ◽  
Gap Formation ◽  
Neotropical Forests ◽  
Phase Dynamics ◽  
Seasonally Dry ◽  
High Resource ◽  
Tree Community ◽  
Dry Tropical Forests ◽  
History Of

Isolated canopy gaps involving one to several trees occur continuously and frequently in many moist and wet neotropical forests (sensu Holdridge et al.1971), shaping tree community structure through a shifting mosaic of patches of high resource availability for small and young trees (Denslow 1980). Though there are few relevant data (Jans et al. 1993), forests with significant seasonal drought are expected to have lower rates of canopy-gap formation (gaps ha-1 γ-1), smaller gap sizes, and, thus, lower rates of canopy disturbance (%γ-1, see review in Whigham et al. 1999). At the extreme, very dry tropical forests do not appear to fit the gap-phase dynamics concept (Swaine et al. 1990).

Seasonal gas exchange and resource-use efficiency in evergreen versus deciduous species from a tropical dry forest

2019 ◽  
Vol 39 (9) ◽  
pp. 1561-1571 ◽  
Author(s):  
Eleinis Ávila-Lovera ◽  
Rosa Urich ◽  
Ilsa Coronel ◽  
Wilmer Tezara
Keyword(s):  
Gas Exchange ◽  
Photosynthetic Rate ◽  
Isotope Composition ◽  
Nitrogen Concentration ◽  
Dry Forest ◽  
Leaf Phenology ◽  
Plant Responses ◽  
Deciduous Species ◽  
Leaf Economics Spectrum ◽  
Use Efficiency

Abstract Tropical dry forests (TDFs) experience a long dry season in which plant species are subject to several months of water deficit. However, TDFs maintain a diverse group of plant life forms, growth forms and leaf phenology, and it is not clear how they vary in their mechanisms for coping with seasonal drought. We studied seasonal changes in leaf water potential (Ψleaf), gas exchange, photochemical activity and functional traits in evergreen and drought-deciduous species from a TDF to determine if leaf phenology mediates plant responses to drought. We found seasonal decreases in Ψleaf, stomatal conductance (gs) and transpiration rate (E), and increases in both intrinsic and instantaneous water-use efficiency. We did not find seasonal differences in photosynthetic rate (Aarea) and carbon isotope composition (δ13C); however, these traits differed between leaf phenology groups, with drought-deciduous plants having higher Aarea and δ13C than evergreen plants. We also found that plants with high leaf nitrogen concentration (Narea) also had low mass-based photosynthetic rate (Amass), photosynthetic-nitrogen-use efficiency and specific leaf area, contrary to the expected relationships given by the leaf economics spectrum. Despite higher Narea, sclerophyllous leaves maintained lower Amass, and this increased structural toughness of leaves may be imposing a stronger limitation for CO2 diffusion and hence photosynthesis. Overall, we found more water-conservative traits in deciduous than in evergreen plants, contrary to what is known about these two leaf phenology groups in other seasonal sites both at tropical and temperate latitudes.

scholarly journals Community, Dominant Tree Species Leaf Phenology and Seasonality in a Tropical Dry Forest, India

2020 ◽  
pp. 34-49
Author(s):  
Appaji Nanda ◽  
Hebbalalu S. Suresh ◽  
Yelugere L. Krishna Murthy
Keyword(s):  
Life Form ◽  
Climatic Variability ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Community Level ◽  
Leaf Phenology ◽  
Circular Statistics ◽  
Individual Species ◽  
Leaf Life Span ◽  
Multiple Regressions

Aims: Plant phenology is a tool to assess climate variability, but less is known about the differences in phenological sensitivity at community, life-form and individual species level. The aim of the present study is to know the contribution of individual, life-form leaf phenophases within the community. Methodology: The leaf phenology of tropical dry forest trees in Bhadra wildlife sanctuary, Karnataka, India was observed during June 2004 to May 2009. A total of 277 trees belonging to 45 species were monitored on monthly basis for different phenophases of leaf phenology. Simple Spearman’s correlations and multiple regressions were performed between different phenophases and environmental factors like rainfall and temperature. Seasonality was determined with circular statistics analyses using the phenological variables and dates of observation. Results: The influence of temperature was stressed with multiple regressions. Seasonality of each of the phenophases was also tested with circular statistics. There is a strong seasonality observed in all phenophases, the strength of seasonality was highest with leafless phenophases. Leafing phenophases among some dominant species within the community was described for seasonality and differences among them were also analyzed. Understorey species had longer leaf life span compared to canopy species. At the community level different phenophases are distinctly seasonal, though the strength of seasonality varied considerably with flushing and expansion of leaves, the strength of the seasonality was high with leaf senescence for all species. Conclusion: The results of this research are in agreement with previous study but the present study suggests that community, population and individual sensitivity might vary under the present context of increasing climatic variability and their adaptation helps to understand the climatic influence in shaping phenology at individual, species and community level.

scholarly journals Phenological synchrony and seasonality of tree species in a fragmented landscape in the Colombian Andes

2020 ◽  
Vol 68 (3) ◽  
pp. 987-1000
Author(s):  
Germán A. Corredor-Londoño ◽  
José William Beltrán ◽  
Alba Marina Torres-González ◽  
Antonella Sardi
Keyword(s):  
Tree Species ◽  
Climatic Variables ◽  
Circular Statistics ◽  
Reproductive Phenology ◽  
Rainfall Regime ◽  
Fragmented Landscape ◽  
Annual Species ◽  
Open Flower ◽  
Neotropical Forests ◽  
Phenological Synchrony

Introduction: In Neotropical forests with high seasonality, climatic variables generally exert a strong influence on plant phenology. Objetive: To describe the reproductive phenology of eight tree species in a fragmented forest landscape, as well as to evaluate the seasonality and their phenological synchrony. Methods: The observations were performed over two years on the foothills of Los Farallones de Cali National Park, in southwestern Colombia. We applied circular statistics to detect seasonal trends, calculate intraspecific synchrony and identify correlations between phenophases and climatic variables. Results: Flowering and fruiting were significantly seasonal in most species. The flowering and fruiting patterns were annual (e.g. Henriettea seemannii, Ocotea aurantiodora, Schefflera morototoni, Lacistema aggregatum) or sub-annual (e.g. Eugenia cf. egensis, Erythroxylum citrifolium, Miconia minutiflora, M. rubiginosa). The open flower and mature fruit phenophases at the community level were continual and bimodal. Each species had high intraspecific population synchrony of open flowers and ripe fruits. Precipitation, relative humidity, temperature and solar irradiance were correlated to flowering and fruiting peaks, except in E. cf. egensis. Conclusions: The annual species showed high phenological synchrony, although the rainfall regime showed variations between years; thus, they seem to be less sensitive to climatic variation than the sub-annual species. Our results indicate that climatic variables partially control the flowering and fruiting rhythms of the eight tree species in this study.

Phenological dynamics of Croton heliotropiifolius populations in a savanna/caatinga gradient, Chapada Diamantina, Brazil

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Thayse Moreira Costa ◽  
Marília Grazielly Mendes dos Santos ◽  
Sâmia Paula Santos Neves ◽  
Lia d`Afonsêca Pedreira de Miranda ◽  
Ligia Silveira Funch
Keyword(s):  
Environmental Gradients ◽  
Abiotic Factors ◽  
Dry Season ◽  
Circular Statistics ◽  
Suitable Model ◽  
Spearman Correlation ◽  
Chapada Diamantina ◽  
Study Sites ◽  
The Relationship ◽  
Phenological Diversity

Abstract The relationship between phenology and environmental factors is critical to understanding population dynamics in environmental gradients. We evaluated phenological variations in Croton heliotropiifolius Kunth in sites with contrasting water resource availability in caatinga, cerrado/caatinga transition, and cerrado in the Chapada Diamantina, Brazil. The phenophases of 81 individuals (n = 27 individuals/area) were recorded monthly for 12 months. Multiple regression, Spearman correlation, circular statistics, Shannon-Wiener diversity, and Morisita-Horn indices were used to test relationships between phenophases and abiotic factors, phenological seasonality, diversity, and similarities between the three populations. The vegetative behaviors in the study sites were distinct in terms of their intensity, seasonality, and synchrony; but reproductive phenophases maintained similar characteristics. Phenological events were positively related to rainfall and soil water availability. C. heliotropiifolius populations exhibited high levels of vegetative phenological diversity, except in the caatinga during the dry season. Reproductive phenological diversity varied along the studied period in the three sites, with higher reproductive than vegetative similarities among populations. Differences in soil types and rainfall volumes in the dry season, even at small distances, therefore make the savanna/caatinga gradient a suitable model for investigating phenological responses related to plant eco-hydrological strategies in seasonally tropical dry ecosystems.

Ungulate biomass across a rainfall gradient: a comparison of data from neotropical and palaeotropical forests and local analyses in Mexico

2009 ◽  
Vol 26 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Salvador Mandujano ◽  
Eduardo J. Naranjo
Keyword(s):  
Local Level ◽  
Tropical Dry Forest ◽  
Biosphere Reserve ◽  
Dry Forest ◽  
Dry Forests ◽  
Rainfall Gradient ◽  
Neotropical Forests ◽  
Data Set ◽  
Precipitation Regimes ◽  
Polynomial Models

Abstract:Using a data set from 36 studies, we evaluated variation in ungulate biomass across a rainfall gradient using polynomial models, aiming to: (1) compare neotropical and palaeotropical dry and wet forests as well as African savannas; and (2) evaluate the usefulness of polynomial models to predict ungulate biomass at neotropical sites using data from a dry forest (Chamela-Cuixmala Biosphere Reserve, CCBR) and a wet forest (Montes Azules Biosphere Reserve, MABR) in Mexico. Our results showed that an overestimation of expected ungulate biomass can be obtained for some tropical forests if data from African savannas are included in the model. This overestimation was particularly high for predicted ungulate biomass in neotropical dry forests. These ecosystems sustain different ungulate biomass values even when rainfall is similar. This was particularly true for some tropical dry forests and savannas. Rainfall predicted the expected ungulate biomass in neotropical ecosystems relative to that of palaeotropical ones under similar precipitation regimes, but did not correctly predict the observed ungulate biomass at local level if data outside the Neotropics are included in the model. This was more evident when we compared observed biomass against predicted biomass in the tropical dry forest of CCBR, while some polynomial models successfully predicted the observed biomass for the tropical wet forest of MABR. Factors such as Pleistocene extinctions and the absence of large, native grazers (i.e. Bovidae) that have kept ungulate richness and standing biomass relatively low in neotropical forests should be accounted for when comparing data sets from different regions.

Resistance of some plum cultivars and individual trees to Plum Pox (Sharka) virus

Agronomie ◽  
1981 ◽  
Vol 1 (8) ◽  
pp. 617-622 ◽  
Author(s):  
D. ŠUTI ◽  
M. RANKOVIĆ
Keyword(s):  
Individual Trees ◽  
Sharka Virus

Female Maylandia zebra prefer victorious males

2018 ◽  
Author(s):  
David Thomas Mellor ◽  
Catherine Tarsiewicz ◽  
Rebecca Jordan
Keyword(s):  
Lake Malawi ◽  
Laboratory Setting ◽  
Widespread Species ◽  
Haplochromine Cichlids ◽  
Experimentally Induced

Females of a widespread species of the rock‐dwelling haplochromine cichlids of Lake Malawi, Maylandia zebra, show preference for males that successfully evict intruding males from their territory. This behaviour, experimentally induced by the investigators in a laboratory setting, was also preferred over males that were not permitted to interact with any other individual.

Temporal dynamics of mycorrhizal fungal communities and co-associations with grassland plant communities following experimental manipulation of rainfall

2019 ◽  
Author(s):  
Coline Deveautour ◽  
Sally Power ◽  
Kirk Barnett ◽  
Raul Ochoa-Hueso ◽  
Suzanne Donn ◽  
...  
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Fungal Community ◽  
Mycorrhizal Fungi ◽  
Temporal Dynamics ◽  
Arbuscular Mycorrhizal ◽  
Fungal Communities ◽  
Plant Responses ◽  
Rainfall Regimes

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.

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