scholarly journals Throughfall and temporal trends of rainfall redistribution in an open tropical rainforest, south-western Amazonia (Rondônia, Brazil)

2005 ◽  
Vol 2 (6) ◽  
pp. 2707-2738 ◽  
Author(s):  
S. Germer ◽  
H. Elsenbeer ◽  
J. M. Moraes
Keyword(s):  
Forest Floor ◽  
Rainfall Intensity ◽  
Tropical Rainforest ◽  
Leaf Growth ◽  
Temporal Trends ◽  
Tropical Rainforests ◽  
Intensity Threshold ◽  
Vegetation Characteristics ◽  
Rain Events ◽  
Shading Effects

Abstract. Throughfall volumes and incident rainfall were measured between 23 August and 2 December 2004 as well as from 6 January to 15 April 2005 for individual rain events of differing intensities and magnitudes in an open tropical rainforest in Rondônia, Brazil. Temporal patterns of throughfall spatial variability were examined. Estimated interception losses were compared to modeled interception losses obtained by applying the revised Gash model in order to identify sources of throughfall variability in open tropical rainforests. Gross precipitation of 97 events amounted to 1309 mm, 89±5.6% (S.E.) of which reached the forest floor as throughfall. The redistribution of water within the canopy was highly variable in time, which we attribute to the high density of babassu palms (Orbignya phalerata), their seasonal leaf growth, and their conducive morphology. We identified a 10-min rainfall intensity threshold of 30 mm h−1 above which interception losses were highly variable. This variability is amplified by funneling and shading effects of palms. This interaction between a rainfall variable and vegetation characteristics is relevant for understanding the hydrology of all tropical rainforests with a high palm density.

scholarly journals Throughfall and temporal trends of rainfall redistribution in an open tropical rainforest, south-western Amazonia (Rondônia, Brazil)

2006 ◽  
Vol 10 (3) ◽  
pp. 383-393 ◽  
Author(s):  
S. Germer ◽  
H. Elsenbeer ◽  
J. M. Moraes
Keyword(s):  
Forest Floor ◽  
Rainfall Intensity ◽  
Tropical Rainforest ◽  
Leaf Growth ◽  
Temporal Trends ◽  
Tropical Rainforests ◽  
Intensity Threshold ◽  
Vegetation Characteristics ◽  
Rain Events ◽  
Shading Effects

Abstract. Throughfall volumes and incident rainfall were measured between 23 August and 2 December 2004 as well as from 6 January to 15 April 2005 for individual rain events of differing intensities and magnitudes in an open tropical rainforest in Rondônia, Brazil. Temporal patterns of throughfall spatial variability were examined. Estimated interception was compared to modeled interception obtained by applying the revised Gash model in order to identify sources of throughfall variability in open tropical rainforests. Gross precipitation of 97 events amounted to 1309 mm, 89±5.6% (S.E.) of which reached the forest floor as throughfall. The redistribution of water within the canopy was highly variable in time, which we attribute to the high density of babassu palms (Orbignya phalerata), their seasonal leaf growth, and their conducive morphology. We identified a 10-min rainfall intensity threshold of 30 mmh-1 above which interception was highly variable. This variability is amplified by funneling and shading effects of palms. This interaction between a rainfall variable and vegetation characteristics is relevant for understanding the hydrology of all tropical rainforests with a high palm density.

On the Effectiveness of Hand Collection to Complement Baits When Studying Ant Vertical Stratification in Tropical Rainforests

Sociobiology ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 213
Author(s):  
Reuber Antoniazzi ◽  
Diana Ahuatzin ◽  
Jaime Pelayo-Martínez ◽  
Liliana Ortiz-Lozada ◽  
Maurice Leponce ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Forest Floor ◽  
Sampling Method ◽  
Tropical Rainforest ◽  
Sampling Methods ◽  
Search Time ◽  
Tropical Rainforests ◽  
Additional Advantage ◽  
Key Factor

Choosing an appropriate sampling method to study ants is a key factor since distinct sampling methods can capture distinct ant fauna and, therefore, leading to bias in the interpretation and conclusion of the patterns observed. Despite it is well known that the ant fauna is vertically stratified, some of the sampling methods cannot be used throughout the whole vertical stratum (e.g., fogging and Winkler extractor). Here we compared the complementarity of hand collecting and baiting (with tuna or honey) in ant surveys focused on the stratification of the ant fauna in a tropical rainforest in Mexico. We found a total of 44 ant species, belonging to 17 genera and five subfamilies. The three sampling methods were clearly complementary at both the forest floor and canopy levels, even with as little as 10 minutes of search time for hand collecting. The ant species composition differed among sampling methods at both vertical strata. Hand collecting yielded higher ant species richness and more exclusive species than either bait at both vertical strata, but both tuna and honey baits also led to the detection of some (though fewer) exclusive ant species. The combination of hand collecting, tuna, and honey baits should thus be considered complementary tools for ant inventories, since using the two methods together yielded more complete inventories at both vertical strata. An additional advantage is that both methods can be used in both strata, ensuring that data in different vertical strata are comparable and allowing more reliable comparisons among these different habitats.

Functional association between apogeotropic aerial roots, mycorrhizas and paper-barked stems in a lowland tropical rainforest in North Queensland

1996 ◽  
Vol 12 (6) ◽  
pp. 763-777 ◽  
Author(s):  
Paul Reddell ◽  
Michael S. Hopkins ◽  
Andrew W. Graham
Keyword(s):  
Mycorrhizal Fungi ◽  
Forest Floor ◽  
Tropical Rainforest ◽  
Strong Association ◽  
Basal Area ◽  
Arbuscular Mycorrhizal ◽  
Coastal Site ◽  
Aerial Roots ◽  
Consistent Feature ◽  
Eleven Species

ABSTRACTThe root and trunk characteristics of species in a complex, lowland, evergreen, tropical rainforest at a seasonally inundated, coastal site on siliceous sands were examined. Roots in the soil were predominantly colonized by arbuscular mycorrhizal fungi although ectomycorrhizas were found on four species which contributed almost 25% of total basal area. Surface root mats were not a characteristic of the study site. In contrast, the ability to produce apogeotropic (upwardly growing) aerial roots which grew on and within the bark on trunks and branches was a consistent feature of the dominant species of trees in this forest. Eleven species representing eight families and constituting more than 85% of the basal area at the site produced these roots. Most trunks with DBH greater than 20 cm supported apogeotropic aerial roots produced by a range of species including themselves. Apogeotropic roots were most frequently found on the basal 0.5 m of trunks; however, they did occur up to 5 m above the forest floor. Apogeotropic aerial roots originated both from epicormic buds under the bark and from soil, and they were frequently colonized by arbuscular mycorrhizal and ectomycorrhizal fungi. There was a strong association between the ability to support these upwardly growing roots and the occurrence of laminated papery and flaky bark. We postulate that production of apogeotropic roots may provide a mechanism for nutrient uptake and root respiration during periods of inundation, for intercepting nutrients in stemflow and/or for extracting nutrients from bark.

Litter decomposition and nutrient release in a tropical rainforest, Southern Bakundu Forest Reserve, Cameroon

1995 ◽  
Vol 11 (3) ◽  
pp. 333-350 ◽  
Author(s):  
Nicholas C. Songwe ◽  
D. U. U. Okali ◽  
F. E. Fasehun
Keyword(s):  
Forest Floor ◽  
Tropical Rainforest ◽  
Great Influence ◽  
Wood Decay ◽  
Nutrient Release ◽  
Dry Weight ◽  
Nitrogen And Phosphorus ◽  
Forest Reserve ◽  
Ceiba Pentandra ◽  
Terminalia Superba

ABSTRACTDecomposition of litter on the forest floor and of leaves of five species, Celtis zenkeri, Cola lepidota, Desbordesia glaucescens, Ceiba pentandra and Terminalia superba in nylon mesh bags, as well as wood decay were studied in the tropical rainforest at Southern Bakundu Forest Reserve, Cameroon.The rate of loss of dry matter was fastest in Celtis zenkeri which was significantly different from the other species, while potassium was the most rapidly released element from all species with more than 50% being released in the first two months of the experiment. Nitrogen and phosphorus showed initial increases in bagged leaf litter independent of dry weight losses and while nitrogen was later released phosphorus continued to increase reaching 2–3 times the initial concentration. Decomposition constant (k) of litter on the forest floor was found to be 2.23 whereas the mean decomposition constants of the different species were as follows: Celtis zenkeri 4.18, Cola lepidota 2.18, Desbordesia glaucescens 1.60 and Ceiba pentandra 2.16 for the two experiments.Termites were found to have a very great influence on the decay of the wood of Terminalia superba with decay due to micro-organisms being negligible.

scholarly journals Cerrorchestia taboukeli sp. nov., a new terrestrial amphipod (Amphipoda, Talitridae) from Martinique Island

2019 ◽  
Author(s):  
Christoph Piscart ◽  
Khaoula Ayati ◽  
Mathieu Coulis
Keyword(s):  
New Species ◽  
Central America ◽  
Forest Floor ◽  
Quantitative Methods ◽  
Tropical Rainforest ◽  
Ecological Data ◽  
Terrestrial Invertebrates ◽  
Caribbean Islands ◽  
The Caribbean ◽  
A New Species

During recent investigations on the terrestrial invertebrates of the tropical rainforest on Martinique Island (Pitons du Carbet), specimens of a new species of the terrestrial amphipod genus Cerrorchestia Lindeman, 1990, C. taboukeli sp. nov., were collected by means of different quantitative and non-quantitative methods (hand collection and Tullgren extraction) in the forest floor. The new species can be easily distinguished from the only other species of the genus, C. hyloraina Lindeman, 1990, by gnathopod 2 (carpus short, palm longer than wide), pereopod 4 dactylus with a denticulate patch, pereopod 5 basis ovate with a deep posterodistal lobe reaching the distal end of the ischium, pleopod 3 ramus with more than six articles. Cerrorchestia tabouleki sp. nov. is the first forest-hopper discovered in the Lesser Antilles, raising the question of island colonization by terrestrial amphipods. Ecological data and a key to terrestrial Talitridae of Central America and the Caribbean islands are provided.

scholarly journals In situ measurements of isoprene and monoterpenes within a south-east Asian tropical rainforest

2011 ◽  
Vol 11 (14) ◽  
pp. 6971-6984 ◽  
Author(s):  
C. E. Jones ◽  
J. R. Hopkins ◽  
A. C. Lewis
Keyword(s):  
Tropical Rainforest ◽  
East Asian ◽  
Ground Level ◽  
Ambient Air ◽  
Tropical Rainforests ◽  
Light Conditions ◽  
Mixing Ratios ◽  
Volatile Carbon ◽  
Malaysian Borneo

Abstract. Biogenic volatile organic compounds (BVOCs) emitted from tropical rainforests comprise a substantial fraction of global atmospheric VOC emissions, however there are only relatively limited measurements of these species in tropical rainforest regions. We present observations of isoprene, α-pinene, camphene, Δ-3-carene, γ-terpinene and limonene, as well as oxygenated VOCs (OVOCs) of biogenic origin such as methacrolein, in ambient air above a tropical rainforest in Malaysian Borneo during the Oxidant and Particle Photochemical Processes above a south-east Asian tropical rainforest (OP3) project in 2008. Daytime composition was dominated by isoprene, with an average mixing ratio of the order of ~1 ppb. γ-terpinene, limonene and camphene were the most abundant monoterpenes, with average daytime mixing ratios of 102, 71 and 66 ppt respectively, and with an average monoterpene toisoprene ratio of 0.3 during sunlit hours, compared to 2.0 at night. Limonene and camphene abundances were seen to be related to both temperature and light conditions. In contrast, γ-terpinene emission continued into the late afternoon/evening, under relatively low temperature and light conditions. The contributions of isoprene, monoterpenes and other classes of VOC to the volatile carbon budget and OH reactivity have been summarised for this rainforest location. We observe good agreement between surface and aircraft measurements of boundary layer isoprene and methacrolein above the natural rainforest, suggesting that the ground-level observations are broadly representative of isoprene emissions from this region.

scholarly journals The MSG Technique: Improving Commercial Microwave Link Rainfall Intensity by Using Rain Area Detection from Meteosat Second Generation

2021 ◽  
Vol 13 (16) ◽  
pp. 3274
Author(s):  
Kingsley K. Kumah ◽  
Joost C. B. Hoedjes ◽  
Noam David ◽  
Ben H. P. Maathuis ◽  
H. Oliver Gao ◽  
...  
Keyword(s):  
Second Generation ◽  
Rainfall Intensity ◽  
Rain Gauge ◽  
Conventional Technique ◽  
Rain Area ◽  
Evaluation Scores ◽  
Rain Events ◽  
Spatially Varying ◽  
Microwave Link ◽  
Rainfall Estimates

Commercial microwave link (MWL) used by mobile telecom operators for data transmission can provide hydro-meteorologically valid rainfall estimates according to studies in the past decade. For the first time, this study investigated a new method, the MSG technique, that uses Meteosat Second Generation (MSG) satellite data to improve MWL rainfall estimates. The investigation, conducted during daytime, used MSG optical (VIS0.6) and near IR (NIR1.6) data to estimate rain areas along a 15 GHz, 9.88 km MWL for classifying the MWL signal into wet–dry periods and estimate the baseline level. Additionally, the MSG technique estimated a new parameter, wet path length, representing the length of the MWL that was wet during wet periods. Finally, MWL rainfall intensity estimates from this new MSG and conventional techniques were compared to rain gauge estimates. The results show that the MSG technique is robust and can estimate gauge comparable rainfall estimates. The evaluation scores every three hours of RMSD, relative bias, and r2 based on the entire evaluation period results of the MSG technique were 2.61 mm h−1, 0.47, and 0.81, compared to 2.09 mm h−1, 0.04, and 0.84 of the conventional technique, respectively. For convective rain events with high intensity spatially varying rainfall, the results show that the MSG technique may approximate the actual mean rainfall estimates better than the conventional technique.

scholarly journals Simulating atmospheric composition over a South-East Asian tropical rainforest: Performance of a chemistry box model

2009 ◽  
Vol 9 (5) ◽  
pp. 19243-19278 ◽  
Author(s):  
T. A. M. Pugh ◽  
A. R. MacKenzie ◽  
C. N. Hewitt ◽  
B. Langford ◽  
P. M. Edwards ◽  
...  
Keyword(s):  
Tropical Rainforest ◽  
Measurement Model ◽  
Model Fit ◽  
Box Model ◽  
Atmospheric Composition ◽  
Tropical Rainforests ◽  
Model Studies ◽  
Chemical Scheme ◽  
Best Fit ◽  
Malaysian Borneo

Abstract. Atmospheric composition and chemistry above tropical rainforests is currently not well established, particularly for south-east Asia. In order to examine our understanding of chemical processes in this region, the performance of a box model of atmospheric boundary layer chemistry is tested against measurements made at the top of the rainforest canopy near Danum Valley, Malaysian Borneo. Multi-variate optimisation against ambient concentration measurements was used to estimate average canopy-scale emissions for isoprene, total monoterpenes and nitric oxide. The excellent agreement between estimated values and measured fluxes of isoprene and total monoterpenes provides confidence in the overall modelling strategy, and suggests that this method may be applied where measured fluxes are not available. The largest contributors to the optimisation cost function at the point of best-fit are OH (41%), NO (18%) and total monoterpenes (16%). Several factors affect the modelled VOC chemistry. In particular concentrations of methacrolein (MACR) and methyl-vinyl ketone (MVK) are substantially overestimated, and the hydroxyl radical [OH] concentration is substantially underestimated; as has been seen before in tropical rainforest studies. It is shown that inclusion of dry deposition of MACR and MVK and wet deposition of species with high Henry's Law values substantially improves the fit of these oxidised species, whilst also substantially decreasing the OH sink. Increasing [OH] production arbitrarily, through a simple OH recycling mechanism, adversely affects the model fit for volatile organic compounds (VOCs). Given the constraints on isoprene flux provided by measurements, a substantial decrease in the rate of reaction of VOCs with OH is the only remaining option to explain the measurement/model discrepancy for OH. A reduction in the isoprene + OH rate constant of 50–70% is able to produce both isoprene and OH concentrations within error of those measured. Whilst we cannot rule out an important role for missing chemistry, particularly in areas of higher isoprene flux, this study demonstrates that the inadequacies apparent in box and global model studies of tropical VOC chemistry may be more strongly influenced by representation of detailed physical and micrometeorological effects than errors in the chemical scheme.

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