scholarly journals Ecology of soil arthropod fauna in tropical forests: A review of studies from Puerto Rico

1969 ◽  
pp. 185-201
Author(s):  
Grizelle González ◽  
María Fernanda Barberena-Arias
Keyword(s):  
Puerto Rico ◽  
Food Webs ◽  
Tropical Forests ◽  
Climatic Conditions ◽  
High Rate ◽  
Forest Conversion ◽  
Global Changes ◽  
Ecological Studies ◽  
Animal Diversity ◽  
The Tropics

The majority of ecological studies in the tropics deal with organisms participating in grazing food webs, while few deal with the diversity of invertebrates in the soil, leaf litter or dead wood that participate in detrital food webs. For tropical forests, the status of information on soil animal diversity is limited, especially when compared to other ecosystems such as temperate forests, grasslands, and deserts. Given the high rate of forest conversion and persistence of deforestation in the tropics, it is important to study the diversity of its fauna and assess how global changes will affect the linkages between soil biota and ecosystem functioning. This review article focuses on surveys and studies conducted in Puerto Rico, a tropical Caribbean island where a significant number of ecological investigations have focused on the characterization of the edaphic fauna, and how they influence ecosystem processes in forested sites. Results from experimentations suggest that soil fauna is an important determinant of decay and nutrient cycling in these forests. Likewise, this article highlights the importance of methodological constraints in studies that compare these organisms at sites with differing climatic conditions, and focuses on the description of ecological studies related to the effects of microarthropods on litter and wood decay.

SMOS-IC L-VOD reveals that tropical forests did not recover from the strong 2015–2016 El Niño event

2020 ◽  
Author(s):  
Lei Fan ◽  
Jean-pierre Wigneron ◽  
Philippe Ciais ◽  
Ana Bastos ◽  
Martin Brandt ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Land Surface ◽  
Atmospheric Transport ◽  
Low Frequency ◽  
Climatic Conditions ◽  
Severe Drought ◽  
Global Carbon Budget ◽  
Large Spread ◽  
The Tropics ◽  
Atmospheric Inversions

<p>Severe drought and extreme heat associated with the 2015–2016 El Niño event have led to large carbon emissions from the tropical vegetation to the atmosphere. With the return to normal climatic conditions in 2017, tropical forest aboveground carbon (AGC) stocks are expected to partly recover due to increased productivity, but the intensity and spatial distribution of this recovery are unknown. Simulations from land-surface models used in the global carbon budget (GCB) suggest a strong reinvigoration of the tropical land sink after the 2015–2016 El Niño. However, models and atmospheric inversions display large divergences in tropical CO<sub>2</sub> fluxes during the 2017 recovery event. For instance, models predict a total net land sink recovery (2017 sink minus the 2015–2016 average sink) ranging from 0.3 to 2.6 Pg C, and the land sink recovery estimated from five atmospheric inversions ranges from −0.08 to +1.92 Pg C. The results of different inversions show a large spread in the tropics due to the scarcity of stations and uncertainties in atmospheric transport simulations.</p><p>We used low-frequency microwave satellite data (L-VOD) to feature precise monitoring of AGC changes and show that the AGC recovery of tropical ecosystems was slow and that by the end of 2017, AGC had not reached predrought levels of 2014<sup>1</sup>. From 2014 to 2017, tropical AGC stocks decreased by 1.3 Pg C due to persistent AGC losses in Africa (-0.9 Pg C) and America (-0.5 Pg C). Pantropically, drylands recovered their carbon stocks to pre–El Niño levels, but African and American humid forests did not, suggesting carryover effects from enhanced forest mortality.</p><p> </p><p><strong>Reference</strong></p><ol><li>J.-P. Wigneron, L. Fan, P. Ciais, A. Bastos, M. Brandt, J. Chave, S. Saatchi, A. Baccini, R. Fensholt, Tropical forests did not recover from the strong 2015–2016 El Niño event. Science Advances. 6, eaay4603 (2020).</li> </ol>

scholarly journals Hysteresis of tropical forests in the 21st century

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Arie Staal ◽  
Ingo Fetzer ◽  
Lan Wang-Erlandsson ◽  
Joyce H. C. Bosmans ◽  
Stefan C. Dekker ◽  
...  
Keyword(s):  
Climate Change ◽  
Tropical Forests ◽  
Spatial Scales ◽  
Regional Scale ◽  
Climatic Conditions ◽  
Change Scenario ◽  
Amazon Forest ◽  
Recent Climate ◽  
Severe Climate Change ◽  
The Tropics

Abstract Tropical forests modify the conditions they depend on through feedbacks at different spatial scales. These feedbacks shape the hysteresis (history-dependence) of tropical forests, thus controlling their resilience to deforestation and response to climate change. Here, we determine the emergent hysteresis from local-scale tipping points and regional-scale forest-rainfall feedbacks across the tropics under the recent climate and a severe climate-change scenario. By integrating remote sensing, a global hydrological model, and detailed atmospheric moisture tracking simulations, we find that forest-rainfall feedback expands the geographic range of possible forest distributions, especially in the Amazon. The Amazon forest could partially recover from complete deforestation, but may lose that resilience later this century. The Congo forest currently lacks resilience, but is predicted to gain it under climate change, whereas forests in Australasia are resilient under both current and future climates. Our results show how tropical forests shape their own distributions and create the climatic conditions that enable them.

scholarly journals Hysteresis of tropical forests in the 21st century

2020 ◽  
Author(s):  
Arie Staal ◽  
Ingo Fetzer ◽  
Lan Wang-Erlandsson ◽  
Joyce Bosmans ◽  
Stefan Dekker ◽  
...  
Keyword(s):  
Climate Change ◽  
Tropical Forests ◽  
Spatial Scales ◽  
Regional Scale ◽  
Climatic Conditions ◽  
Change Scenario ◽  
Amazon Forest ◽  
Recent Climate ◽  
Severe Climate Change ◽  
The Tropics

<p>Tropical forests modify the conditions they depend on through feedbacks on different spatial scales. These feedbacks shape the hysteresis (history-dependence) of tropical forests, thus controlling their resilience to deforestation and response to climate change. Here we present the emergent hysteresis from local-scale tipping points and regional-scale forest-rainfall feedbacks across the tropics under the recent climate and a severe climate-change scenario. By integrating remote sensing, a global hydrological model, and detailed atmospheric moisture tracking simulations, we find that forest-rainfall feedback expands the range of possible forest distributions especially in the Amazon. The Amazon forest could partially recover from complete deforestation, but may lose that resilience later this century. The Congo forest lacks resilience, but gains it under climate change, whereas forests in Australasia are resilient under both current and future climates. Our results show how tropical forests shape their own distributions and create the climatic conditions that enable them.</p>

scholarly journals Natural durability and improved resistance of 20 Amazonian wood species after 30 years in ground contact

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fernando Nunes Gouveia ◽  
Marcelo Fontana da Silveira ◽  
Alencar Garlet
Keyword(s):  
Wood Species ◽  
Climatic Conditions ◽  
Natural Durability ◽  
Amazon Forest ◽  
Ground Contact ◽  
Forest Environment ◽  
Ground Test ◽  
The Tropics ◽  
Dipteryx Odorata ◽  
Copper Arsenate

Abstract This study aimed to assess the natural durability of 20 Amazonian wood species preserved with chromated copper arsenate (CCA) after 30 years in ground contact in an experimental field test at National Forest of Tapajós, Pará state - Brazil. Heartwood samples with a cross-section of 5 × 5 cm and 50 cm of length were half-buried in soil and inspected every year for decay. The species were classified according to natural durability following the classification method proposed by Findlay (Findlay, W.P.K. (1985). The nature and durability of wood. In: Findlay, W.P.K. (Ed.), Preservation of timber in the tropics. Springer Science, Whitchurch, pp. 1–13). After 30 years in ground test, six species were classified as Perishable, seven as Non-durable, three as Durable and four as Very durable, namely: Trichilia lecointei, Lecythis pisonis, Pseudopiptadenia suaveolens, and Dipteryx odorata (Very durable), Protium tenuifolium, Dinizia excelsa, and Ormosia paraensis (Durable), Endopleura uchi, Goupia glabra, Pouteria egregia, Tachigali chrysophylla, Tachigali paraensis, Vatairea sericea, and Vochysia maxima (Non-durable) and Chrysophyllum lucentifolium, Couratari oblongifolia, Didymopanax morototoni, Lueheopsis duckeana, Sterculia excelsa, and Xylopia nitida (Perishable). CCA preservative treatment was effective to promote timber protection, even under harsh climatic conditions of the Amazon forest environment.

An Empirical Study of the Relationship between Seasonal Precipitation and Thermodynamic Environment in Puerto Rico

2019 ◽  
Vol 34 (2) ◽  
pp. 277-288 ◽  
Author(s):  
Paul W. Miller ◽  
Thomas L. Mote ◽  
Craig A. Ramseyer
Keyword(s):  
Puerto Rico ◽  
Annual Rainfall ◽  
Seasonal Precipitation ◽  
Surface Precipitation ◽  
Precipitation Forecasting ◽  
Caribbean Islands ◽  
K Index ◽  
Groundwater Reserves ◽  
The Tropics ◽  
The Relationship

Abstract With limited groundwater reserves and few reservoirs, Caribbean islands such as Puerto Rico are largely dependent on regular rainfall to meet societal and ecological water needs. Thus, the ability to anticipate seasonal rainfall shortages, such as the 2015 drought, is particularly important, yet few reliable tools exist for this purpose. Consequently, interpolated surface precipitation observations from the Daymet archive are summarized on daily, annual, and seasonal time scales and compared to the host thermodynamic environment as characterized by the Gálvez–Davison index (GDI), a convective potential parameter designed specifically for the tropics. Complementing the Daymet precipitation totals, ≥1.1 million WSR-88D volume scans between 2002 and 2016 were analyzed for echo tops ≥ 10 000 ft (~3 km) to establish a radar-inferred precipitation activity database for Puerto Rico. The 15-yr record reveals that the GDI outperforms several midlatitude-centric thermodynamic indices, explaining roughly 25% of daily 3-km echo top (ET) activity during each of Puerto Rico’s primary seasons. In contrast, neither mean-layer CAPE, the K index, nor total totals explain more than 11% during any season. When aggregated to the seasonal level, the GDI strongly relates to 3-km ET (R2 = 0.65) and Daymet precipitation totals (R2 = 0.82) during the early rainfall season (ERS; April–July), with correlations weaker outside of this period. The 4-month ERS explains 51% (41%) of the variability to Puerto Rico’s annual rainfall during exceptionally wet (dry) years. These findings are valuable for climate downscaling studies predicting Puerto Rico’s hydroclimate in future atmospheric states, and they could potentially be adapted for operational seasonal precipitation forecasting.

scholarly journals Environmental control of natural gap size distribution in tropical forests

2017 ◽  
Vol 14 (2) ◽  
pp. 353-364 ◽  
Author(s):  
Youven Goulamoussène ◽  
Caroline Bedeau ◽  
Laurent Descroix ◽  
Laurent Linguet ◽  
Bruno Hérault
Keyword(s):  
Size Distribution ◽  
Tropical Forests ◽  
Environmental Control ◽  
Global Changes ◽  
Gap Size ◽  
Methodological Framework ◽  
Power Law Distribution ◽  
Dominant Form ◽  
Size Frequency Distribution ◽  
Unmanaged Forest

Abstract. Natural disturbances are the dominant form of forest regeneration and dynamics in unmanaged tropical forests. Monitoring the size distribution of treefall gaps is important to better understand and predict the carbon budget in response to land use and other global changes. In this study, we model the size frequency distribution of natural canopy gaps with a discrete power law distribution. We use a Bayesian framework to introduce and test, using Monte Carlo Markov chain and Kuo–Mallick algorithms, the effect of local physical environment on gap size distribution. We apply our methodological framework to an original light detecting and ranging dataset in which natural forest gaps were delineated over 30 000 ha of unmanaged forest. We highlight strong links between gap size distribution and environment, primarily hydrological conditions and topography, with large gaps being more frequent on floodplains and in wind-exposed areas. In the future, we plan to apply our methodological framework on a larger scale using satellite data. Additionally, although gap size distribution variation is clearly under environmental control, variation in gap size distribution in time should be tested against climate variability.

scholarly journals Crop Response to Soil Acidity Factors in Ultisols and Oxisols in Puerto Rico X1. Cassava.

1969 ◽  
Vol 69 ◽  
pp. 145-151
Author(s):  
Edmundo Rivera ◽  
Fernando Abruña ◽  
José Rodríguez
Keyword(s):  
Puerto Rico ◽  
Manihot Esculenta ◽  
Cation Exchange Capacity ◽  
Soil Acidity ◽  
Exchange Capacity ◽  
Manihot Esculenta Crantz ◽  
Cassava Leaves ◽  
Exchangeable Al ◽  
Decreasing Ph ◽  
The Tropics

Cassava (Manihot esculenta Crantz), one of the major sources of carbohydrates throughout the tropics, was found to be very tolerant to high soil acidity in two Ultisols and one Oxisol. About 85% of maximum yields were obtained when Al saturation of the effective cation exchange capacity of the soil was around 60%, but highest yields were attained at about pH 5.3 with no exchangeable Al. Soil acidity factors did not affect the chemical composition of the cassava leaves, except for Mn, which increased with decreasing pH of the Oxisol. Tolerance of cassava to soil acidity was also confirmed by the fact that yields of 12 commercial varieties were not affected by Al saturation levels varying from 0 to 60% in an Ultisol.

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