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1.
J Environ Manage ; 315: 115177, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-35500492

RESUMEN

In tropical forests, several studies have explored the effects of environmental factors and tree species diversity as well as functional trait diversity and trait composition on aboveground biomass (AGB) stock. However, these abiotic and biotic effects on individual biomass variability (BioVar) are still largely unexplored, which limits our understanding of the plant-plant interactions for species coexistence. Here, we used the Partial Least Squares Structural Equation Models (PLS-SEMs), and other complementary analyses, on data from 189 tropical forest plots in Sri Lanka, to test the linkages amongst climate (a latent variable of solar radiation and potential evapotranspiration), soil (pH and cation exchange capacity), plot (plot size and stand density) conditions, big-sized trees, species-functional diversity, and BioVar. The PLS-SEMs showed that climate conditions decreased BioVar directly but increased indirectly via integrative promoting direct effects on soil conditions, species-functional diversity and big-sized trees. In contrast, soil conditions increased BioVar directly but decreased indirectly via integrative suppressing direct effects on species-functional diversity and big-sized trees. Interestingly, we found that the divergent indirect effects of climate and soil conditions on BioVar via big-sized trees mattered when the direct effect of big-sized trees on species-functional diversity was considered as compared to the reverse effect in PLS-SEMs. Also, the indirect positive effect of plot properties on BioVar was nearly equal to the direct effect because plot properties affected big-sized trees as similar as or lower than species-functional diversity. The positive effect of species-functional diversity on BioVar was mediated by the structural attributes of big-sized trees, indicating increased plant species co-existence. This study suggests that individual tree biomass variability (i.e., BioVar) should be considered for managing natural tropical forests in the context of the plant-plant interactions for species coexistence.


Asunto(s)
Biodiversidad , Clima , Biomasa , Suelo , Sri Lanka , Clima Tropical
2.
PLoS One ; 17(4): e0263508, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35442987

RESUMEN

Understanding variation in tree functional traits along topographic gradients and through time provides insights into the processes that will shape community composition and determine ecosystem functioning. In montane environments, complex topography is known to affect forest structure and composition, yet its role in determining trait composition, indices on community climatic tolerances, and responses to changing environmental conditions has not been fully explored. This study investigates how functional trait composition (characterized as community-weighted moments) and community climatic indices vary for the tree community as a whole and for its separate demographic components (i.e., dying, surviving, recruiting trees) over eight years in a topographically complex tropical Andean forest in southern Ecuador. We identified a strong influence of topography on functional composition and on species' climatic optima, such that communities at lower topographic positions were dominated by acquisitive species adapted to both warmer and wetter conditions compared to communities at upper topographic positions which were dominated by conservative cold adapted species, possibly due to differences in soil conditions and hydrology. Forest functional and climatic composition remained stable through time; and we found limited evidence for trait-based responses to environmental change among demographic groups. Our findings confirm that fine-scale environmental conditions are a critical factor structuring plant communities in tropical forests, and suggest that slow environmental warming and community-based processes may promote short-term community functional stability. This study highlights the need to explore how diverse aspects of community trait composition vary in tropical montane forests, and to further investigate thresholds of forest response to environmental change.


Asunto(s)
Ecosistema , Árboles , Bosques , Plantas , Suelo/química , Clima Tropical
3.
Sci Rep ; 12(1): 6882, 2022 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-35477746

RESUMEN

Large-scale abandoned agricultural areas in Southeast Asia resulted in patches of forests of multiple successions and characteristics, challenging the study of their responses to environmental changes, especially under climatic water stress. Here, we investigated seasonal variation in leaf water status and drought tolerance of dominant tree species in three multi-aged tropical forests, ranging from 5 to > 200 years old, with contrasting soil moisture in Thailand. Seasonal variation in leaf water status differed among the forests with trees in young and intermediate sites demonstrating larger differences between seasons than the old-growth forest. Although vulnerability to embolism curves revealed that trees in old-growth forest were potentially more sensitive to declining leaf water status than others, they were predicted to lose < 5% of their hydraulic capacity as opposed to 13% for the trees in the younger sites. Our results suggest that the responses to water stress of tree species in different forest ages greatly vary with a tendency of trees in younger sites to be more resilience than those in older sites. Such information would benefit the selection of tree species that could adapt well to specific environments, thus improving the strategies for managing forests of different ages under a warmer future.


Asunto(s)
Sequías , Árboles , Deshidratación , Bosques , Hojas de la Planta/fisiología , Tailandia , Árboles/fisiología , Clima Tropical
4.
Biol Lett ; 18(4): 20210519, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35382585

RESUMEN

Understanding the causes and consequences of insect declines has become an important goal in ecology, particularly in the tropics, where most terrestrial diversity exists. Over the past 12 years, the ForestGEO Arthropod Initiative has systematically monitored multiple insect groups on Barro Colorado Island (BCI), Panama, providing baseline data for assessing long-term population trends. Here, we estimate the rates of change in abundance among 96 tiger moth species on BCI. Population trends of most species were stable (n = 20) or increasing (n = 62), with few (n = 14) declining species. Our analysis of morphological and climatic sensitivity traits associated with population trends shows that species-specific responses to climate were most strongly linked with trends. Specifically, tiger moth species that are more abundant in warmer and wetter years are more likely to show population increases. Our study contrasts with recent findings indicating insect decline in tropical and temperate regions. These results highlight the significant role of biotic responses to climate in determining long-term population trends and suggest that future climate changes are likely to impact tropical insect communities.


Asunto(s)
Mariposas Nocturnas , Clima Tropical , Animales , Cambio Climático , Colorado , Ecología , Mariposas Nocturnas/fisiología , Árboles
5.
Nat Commun ; 13(1): 1964, 2022 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-35413947

RESUMEN

Biophysical effects from deforestation have the potential to amplify carbon losses but are often neglected in carbon accounting systems. Here we use both Earth system model simulations and satellite-derived estimates of aboveground biomass to assess losses of vegetation carbon caused by the influence of tropical deforestation on regional climate across different continents. In the Amazon, warming and drying arising from deforestation result in an additional 5.1 ± 3.7% loss of aboveground biomass. Biophysical effects also amplify carbon losses in the Congo (3.8 ± 2.5%) but do not lead to significant additional carbon losses in tropical Asia due to its high levels of annual mean precipitation. These findings indicate that tropical forests may be undervalued in carbon accounting systems that neglect climate feedbacks from surface biophysical changes and that the positive carbon-climate feedback from deforestation-driven climate change is higher than the feedback originating from fossil fuel emissions.


Asunto(s)
Carbono/metabolismo , Cambio Climático , Bosques , Clima Tropical , Biomasa , Conservación de los Recursos Naturales , Árboles
6.
PLoS One ; 17(3): e0265439, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35298537

RESUMEN

Strategic irrigation planning and soil water conservation measure can be rewarding for increasing agricultural productivity in a humid subtropical climatic environment. Field experiments were conducted to evaluate broccoli yield response to crop water productivity (CWP), irrigation water productivity (IWP) and economics under varied irrigation regimes and mulching. Four levels of irrigation: surface irrigation at 1.0 IW/CPE (irrigation water to cumulative pan evaporation, I1), drip irrigation at 0.6 (I2), 0.8 (I3) and 1.0 (I4) of crop evapotranspiration (ETc) and three mulches: none (M0), black polythene mulch (BPM, M1) and paddy straw mulch (PSM, M2) were examined. Among these treatments I3M1 produced the higher yield (19.17 t ha-1), CWP, IWP and maximum benefit-cost ratio (BCR), being almost competitive with I3M1. Under scarcity of water, I2M1 was an alternative. Drip irrigation could save 21.2-52.7% water over surface irrigation which accommodated 17.1 to 53.3% additional area under irrigation. Yield response factor and water-yield production function suggested the potential yield decrease in relation to increased deficit irrigation. However, a deficit drip irrigation scheduling with 0.8 ETc at a 3-day interval is optimum for increased curd yield, water productivity and economics of broccoli.


Asunto(s)
Brassica , Agua , Agricultura , Suelo , Clima Tropical , Agua/análisis
7.
PLoS One ; 17(3): e0266222, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35358265

RESUMEN

Tropical forests sustain many ant species whose mating events often involve conspicuous flying swarms of winged gynes and males. The success of these reproductive flights depends on environmental variables and determines the maintenance of local ant diversity. However, we lack a strong understanding of the role of environmental variables in shaping the phenology of these flights. Using a combination of community-level analyses and a time-series model on male abundance, we studied male ant phenology in a seasonally wet lowland rainforest in the Panama Canal. The male flights of 161 ant species, sampled with 10 Malaise traps during 58 consecutive weeks (from August 2014 to September 2015), varied widely in number (mean = 9.8 weeks, median = 4, range = 1 to 58). Those species abundant enough for analysis (n = 97) flew mainly towards the end of the dry season and at the start of the rainy season. While litterfall, rain, temperature, and air humidity explained community composition, the time-series model estimators elucidated more complex patterns of reproductive investment across the entire year. For example, male abundance increased in weeks when maximum daily temperature increased and in wet weeks during the dry season. On the contrary, male abundance decreased in periods when rain receded (e.g., at the start of the dry season), in periods when rain fell daily (e.g., right after the beginning of the wet season), or when there was an increase in the short-term rate of litterfall (e.g., at the end of the dry season). Together, these results suggest that the BCI ant community is adapted to the dry/wet transition as the best timing of reproductive investment. We hypothesize that current climate change scenarios for tropical regions with higher average temperature, but lower rainfall, may generate phenological mismatches between reproductive flights and the adequate conditions needed for a successful start of the colony.


Asunto(s)
Hormigas , Clima Tropical , Animales , Cambio Climático , Bosques , Masculino , Lluvia , Estaciones del Año , Árboles
8.
New Phytol ; 234(4): 1220-1236, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35263440

RESUMEN

While trees can acclimate to warming, there is concern that tropical rainforest species may be less able to acclimate because they have adapted to a relatively stable thermal environment. Here we tested whether the physiological adjustments to warming differed among Australian tropical, subtropical and warm-temperate rainforest trees. Photosynthesis and respiration temperature responses were quantified in six Australian rainforest seedlings of tropical, subtropical and warm-temperate climates grown across four growth temperatures in a glasshouse. Temperature-response models were fitted to identify mechanisms underpinning the response to warming. Tropical and subtropical species had higher temperature optima for photosynthesis (ToptA ) than temperate species. There was acclimation of ToptA to warmer growth temperatures. The rate of acclimation (0.35-0.78°C °C-1 ) was higher in tropical and subtropical than in warm-temperate trees and attributed to differences in underlying biochemical parameters, particularly increased temperature optima of Vcmax25 and Jmax25 . The temperature sensitivity of respiration (Q10 ) was 24% lower in tropical and subtropical compared with warm-temperate species. Overall, tropical and subtropical species had a similar capacity to acclimate to changes in growth temperature as warm-temperate species, despite being grown at higher temperatures. Quantifying the physiological acclimation in rainforests can improve accuracy of future climate predictions and assess their potential vulnerability to warming.


Asunto(s)
Bosque Lluvioso , Árboles , Aclimatación/fisiología , Australia , Dióxido de Carbono , Fotosíntesis/fisiología , Hojas de la Planta/fisiología , Temperatura , Clima Tropical
9.
Sci Total Environ ; 828: 154369, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35259389

RESUMEN

Blue carbon ecosystems are a vital part of nature-based climate solutions due to their capacity to store and sequester carbon, but often exclude macroalgal beds even though they can form highly productive coastal ecosystems. Recent estimates of macroalgal contributions to global carbon sequestration are derived primarily from temperate kelp forests, while tropical macroalgal carbon stock in living biomass is still unclear. Here, using Singapore as a case study, we integrate field surveys and remote sensing data to estimate living macroalgal carbon stock. Results show that macroalgae in Singapore account for up to 650 Mg C biomass stock, which is greater than the aboveground carbon found in seagrass meadows but lower than that in mangrove forests. Ulva and Sargassum dominate macroalgal assemblages and biomass along the coast, with both genera exhibiting distinct spatio-temporal variation. The annual range of macroalgal biomass carbon is estimated to be 450 Mg C yr-1, or 0.77 Mg C ha-1 yr-1. Noting the uncertainties of the fate of macroalgal biomass carbon, we estimate the potential sequestration rate and find that it is comparable to mature terrestrial ecosystems such as tropical grasslands and temperate forests. This study demonstrates that macroalgal seasonality allows for a consistent amount of biomass carbon to either be exported and eventually sequestered, or harvested for utilization on an annual basis. These findings on macroalgal growth patterns and their considerable contributions to tropical coastal carbon pool add to the growing support for macroalgae to be formally included in blue carbon assessments.


Asunto(s)
Carbono , Algas Marinas , Biomasa , Secuestro de Carbono , Ecosistema , Bosques , Clima Tropical
10.
Am J Bot ; 109(4): 550-563, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35244206

RESUMEN

PREMISE: Epiphytes are abundant in ecosystems such as tropical montane cloud forests where low-lying clouds are often in contact with vegetation. Climate projections for these regions include more variability in rainfall and an increase in cloud base heights, which would lead to drier conditions in the soil and atmosphere. While recent studies have examined the effects of drought on epiphytic water relations, the influence that atmospheric moisture has, either alone or in combination with drought, on the health and performance of epiphyte communities remains unclear. METHODS: We conducted a 10-week drought experiment on seven vascular epiphyte species in two shadehouses, one with warmer and drier conditions and another that was cooler and more humid. We measured water relations across control and drought-treatment groups and assessed functional traits of leaves produced during drought conditions to evaluate trait plasticity. RESULTS: Epiphytes exposed to drought and drier atmospheric conditions had a significant reduction in stomatal conductance and leaf water potential and an increase in leaf dry matter. Nonsucculent epiphytes from the drier shadehouse had the greatest shifts in functional traits, whereas succulent epiphytes released stored leaf water to maintain water status. CONCLUSIONS: Individuals in the drier shadehouse had a substantial reduction in performance, whereas drought-treated individuals that experienced cloud immersion displayed minimal changes in water status. Our results indicate that projected increases in the cloud base height will reduce growth and performance of epiphytic communities and that nonsucculent epiphytes may be particularly vulnerable.


Asunto(s)
Sequías , Ecosistema , Inmersión , Hojas de la Planta , Árboles , Clima Tropical , Agua
11.
Proc Natl Acad Sci U S A ; 119(14): e2112336119, 2022 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-35349336

RESUMEN

SignificanceOur full-scale comparison of Africa and South America's lowland tropical tree floras shows that both Africa and South America's moist and dry tree floras are organized similarly: plant families that are rich in tree species on one continent are also rich in tree species on the other continent, and these patterns hold across moist and dry environments. Moreover, we confirm that there is an important difference in tree species richness between the two continents, which is linked to a few families that are exceptionally diverse in South American moist forests, although dry formations also contribute to this difference. Plant families only present on one of the two continents do not contribute substantially to differences in tree species richness.


Asunto(s)
Árboles , Clima Tropical , Biodiversidad , Bosques , Plantas , América del Sur
12.
Oecologia ; 198(3): 645-661, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35279723

RESUMEN

Epiphyte communities comprise important components of many forest ecosystems in terms of biomass and diversity, but little is known regarding trade-offs that underlie diversity and structure in these communities or the impact that microclimate has on epiphyte trait allocation. We measured 22 functional traits in vascular epiphyte communities across six sites that span a microclimatic gradient in a tropical montane cloud forest region in Costa Rica. We quantified traits that relate to carbon and nitrogen allocation, gas exchange, water storage, and drought tolerance. Functional diversity was high in all but the lowest elevation site where drought likely limits the success of certain species with particular trait combinations. For most traits, variation was explained by relationships with other traits, rather than differences in microclimate across sites. Although there were significant differences in microclimate, epiphyte abundance, and diversity, we found substantial overlap in multivariate trait space across five of the sites. We found significant correlations between functional traits, many of which related to water storage (leaf water content, leaf thickness, hydrenchymal thickness), drought tolerance (turgor loss point), and carbon allocation (specific leaf area, leaf dry matter content). This suite of trait correlations suggests that the epiphyte community has evolved functional strategies along with a drought avoidance versus drought tolerance continuum where leaf succulence emerged as a pivotal overall trait.


Asunto(s)
Sequías , Clima Tropical , Ecosistema , Bosques , Hojas de la Planta
13.
Trop Anim Health Prod ; 54(2): 141, 2022 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-35332367

RESUMEN

The experiment was conducted at ABIS Buffalo Dairy Farm, Rajnandgaon, on 300 milking Murrah buffaloes. In buffaloes, the information on body measurements, skin thickness, and their associations with milk yield and interrelationship among them is scanty. Hence, the present study was designed to establish the relationship of skin thickness with milk production in Murrah buffaloes. The data was statistically analyzed using R statistical software. The average skin thickness of the neck, chest, abdomen, rump, hind quarter, udder, and flank regions were 6.27 ± 0.11, 6.13 ± 0.13, 7.28 ± 0.14, 9.78 ± 0.15, 8.00 ± 0.12, 4.14 ± 0.09, and 8.53 ± 0.12 mm, respectively. In this study, the skinfold thickness of the neck and chest regions had a highly significant effect (P < 0.01) on the total lactation milk yield of Murrah buffaloes whereas skin thickness of other regions under study had no significant effect on total lactation milk yield. The results of the study revealed that parity and stage of lactation had a significant effect (P < 0.05) on the skinfold thickness of all the seven regions of Murrah buffalo under investigation. The study indicated that except for the udder region the correlation of all skin thickness with TMY was found to be negative and significant. The genetic correlations between milk yield and skin thickness of the neck, abdomen, and udder were low to medium. The heritability estimate for different skinfold thicknesses and milk yield in this study was low to medium. These results could facilitate further exploration in the use of skinfold thickness for management precision and can be useful in the selection of better animals under field conditions.


Asunto(s)
Búfalos , Leche , Animales , Búfalos/genética , Femenino , Lactancia/genética , Glándulas Mamarias Animales , Embarazo , Clima Tropical
14.
Sci Total Environ ; 823: 153314, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35124037

RESUMEN

Seasonal precipitation regime plays a vital role in regulating nutrient dynamics in seasonally dry tropical forests. Present evidence suggests that not only wet season precipitation is increasing in the tropics of South China, but also that the wet season is occurring later. However, it is unclear how nutrient dynamics will respond to the projected precipitation regime changes. We assessed the impacts of altered seasonal precipitation on soil net N mineralization in a secondary tropical forest. Since 2013, by reducing throughfall and/or irrigating experimental plots, we delayed the wet season by two months from April-September to June-November (DW treatment) or increased annual precipitation by 25% in July and August (WW treatment). We measured soil net N mineralization rates and assessed soil microbial communities in January, April, August and November in 2015 and 2017. We found that a wetter wet season did not significantly affect soil microbes or net N mineralization rates, even in the mid-wet season (August) when soil water content in the WW treatment increased significantly. By contrast, a delayed wet season enhanced soil microbial biomass and altered microbial community structure, resulting in a two-fold increase in net N mineralization rates relative to controls in the early dry season (November). Structural equation modeling showed that the changes in net N mineralization during the early dry season were associated with altered soil microbial communities, dissolved organic N, and litterfall, which were all affected by enhanced soil water content. Our findings suggest that a delayed wet season could have a greater impact on N dynamics than increased precipitation during the wet season. Changes in the seasonal timing of rainfall might therefore influence the functioning of seasonally dry tropical forests.


Asunto(s)
Bosques , Suelo , Biomasa , Estaciones del Año , Suelo/química , Microbiología del Suelo , Clima Tropical
15.
Nat Plants ; 8(2): 104-109, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35115726

RESUMEN

The latitudinal biodiversity gradient, with tropical regions acting as 'evolutionary cradles', is a cornerstone of current biogeographical and ecological theory1. In the modern world floral biodiversity and biomass are overwhelmingly concentrated in the tropics, and it is often assumed that the tropics were evolutionary cradles throughout land plant evolutionary history. For example, the origination and diversification of angiosperms is believed to have taken place in the Cretaceous tropics2 and modern gymnosperms in the Permian tropics3. Here, we show that during the first major diversification of land plants, in the Late Silurian-Early Devonian, land plant biodiversity was much lower at the equator compared to medium-high southern latitudes. Throughout this crucial interval of plant evolution, tropical vegetation remained depauperate and of very low taxonomic biodiversity, although with similar morphological disparity to the more diverse higher latitude floras. Possible explanations for this low tropical floral biodiversity include palaeocontinental configuration or adverse palaeotropical environmental conditions. We discount the possibility that it was simply a fortuitous feature of the biogeographical spread of the earliest vascular land plants.


Asunto(s)
Magnoliopsida , Clima Tropical , Biodiversidad , Evolución Biológica , Cycadopsida , Filogenia
16.
Water Res ; 212: 118129, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35121419

RESUMEN

Cyanobacterial blooms that produce toxins occur in freshwaters worldwide and yet, the occurrence and distribution patterns of many cyanobacterial secondary metabolites particularly in tropical regions are still not fully understood. Moreover, predictive models for these metabolites by using easily accessible water quality indicators are rarely discussed. In this study, we investigated the co-occurrence and spatiotemporal trends of 18 well-known and less-studied cyanobacterial metabolites (including [D-Asp3] microcystin-LR (DM-LR), [D-Asp3] microcystin-RR (DM-RR), microcystin-HilR (MC-HilR), microcystin-HtyR (MC-HtyR), microcystin-LA (MC-LA), microcystin-LF (MC-LF), microcystin-LR (MC-LR), microcystin-LW (MC-LW), microcystin-LY (MC-LY), microcystin-RR (MC-RR) and microcystin-WR (MC-WR), Anatoxin-a (ATX-a), homoanatoxin-a (HATX-a), cylindrospermospin (CYN), nodularin (NOD), anabaenopeptin A (AptA) and anabaenopeptin B (AptB)) in a tropical freshwater lake often plagued with blooms. Random forest (RF) models were developed to predict MCs and CYN and assess the relative importance of 22 potential predictors that determined their concentrations. The results showed that 11 MCs, CYN, ATX-a, HATX-a, AptA and AptB were found at least once in the studied water body, with MC-RR and CYN being the most frequently occurring, intracellularly and extracellularly. AptA and AptB were detected for the first time in tropical freshwaters at low concentrations. The metabolite profiles were highly variable at both temporal and spatial scales, in line with spatially different phytoplankton assemblages. Notably, MCs decreased with the increase of CYN, possibly revealing interspecific competition of cyanobacteria. The rapid RF prediction models for MCs and CYN were successfully developed using 4 identified drivers (i.e., chlorophyll-a, total carbon, rainfall and ammonium for MCs prediction; and chloride, total carbon, rainfall and nitrate for CYN prediction). The established models can help to better understand the potential relationships between cyanotoxins and environmental variables as well as provide useful information for making policy decisions.


Asunto(s)
Cianobacterias , Eutrofización , Microcistinas , Clorofila A , Lagos/análisis , Clima Tropical
17.
Ecol Lett ; 25(5): 1126-1138, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35128774

RESUMEN

Tree mortality is a major control over tropical forest carbon stocks globally but the strength of associations between abiotic drivers and tree mortality within forested landscapes is poorly understood. Here, we used repeat drone photogrammetry across 1500 ha of forest in Central Panama over 5 years to quantify spatial variation in canopy disturbance rates and its predictors. We identified 11,153 canopy disturbances greater than 25 m2 in area, including treefalls, large branchfalls and standing dead trees, affecting 1.9% of area per year. Soil type, forest age and topography explained up to 46%-67% of disturbance rate variation at spatial grains of 58-64 ha, with higher rates in older forests, steeper slopes and local depressions. Furthermore, disturbance rates predicted the proportion of low canopy area across the landscape, and mean canopy height in old growth forests. Thus abiotic factors drive variation in disturbance rates and thereby forest structure at landscape scales.


Asunto(s)
Bosques , Suelo , Carbono , Panamá , Árboles , Clima Tropical
18.
Sci Data ; 9(1): 45, 2022 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-35145119

RESUMEN

Fish swimming capacity is a key life history trait critical to many aspects of their ecology. U-crit (critical) swimming speeds provide a robust, repeatable relative measure of swimming speed that can serve as a useful surrogate for other measures of swimming performance. Here we collate and make available one the most comprehensive datasets on U-crit swimming abilities of tropical marine fish larvae and pelagic juveniles, most of which are reef associated as adults. The dataset includes U-crit speed measurements for settlement stage fishes across a large range of species and families obtained mostly from field specimens collected in light traps and crest nets; and the development of swimming abilities throughout ontogeny for a range of species using reared larvae. In nearly all instances, the size of the individual was available, and in many cases, data include other morphological measurements (e.g. "propulsive area") useful for predicting swimming capacity. We hope these data prove useful for further studies of larval swimming performance and other broader syntheses.


Asunto(s)
Peces , Larva , Natación , Animales , Ecología , Clima Tropical
19.
New Phytol ; 234(5): 1664-1677, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35201608

RESUMEN

Tree size shapes forest carbon dynamics and determines how trees interact with their environment, including a changing climate. Here, we conduct the first global analysis of among-site differences in how aboveground biomass stocks and fluxes are distributed with tree size. We analyzed repeat tree censuses from 25 large-scale (4-52 ha) forest plots spanning a broad climatic range over five continents to characterize how aboveground biomass, woody productivity, and woody mortality vary with tree diameter. We examined how the median, dispersion, and skewness of these size-related distributions vary with mean annual temperature and precipitation. In warmer forests, aboveground biomass, woody productivity, and woody mortality were more broadly distributed with respect to tree size. In warmer and wetter forests, aboveground biomass and woody productivity were more right skewed, with a long tail towards large trees. Small trees (1-10 cm diameter) contributed more to productivity and mortality than to biomass, highlighting the importance of including these trees in analyses of forest dynamics. Our findings provide an improved characterization of climate-driven forest differences in the size structure of aboveground biomass and dynamics of that biomass, as well as refined benchmarks for capturing climate influences in vegetation demographic models.


Asunto(s)
Carbono , Clima Tropical , Biomasa , Temperatura , Madera
20.
Sci Total Environ ; 823: 153545, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35104526

RESUMEN

An influence of precipitation on the glacier changes over the Qinghai-Tibet Plateau (QTP) is investigated in this paper. The results show that the glacial loss rates of glaciers in the QTP are significantly correlated with the interannual changes of precipitation and low cloud cover. The water vapor, importing with the warm and wet airflows from the Asian Monsoon regions, significantly influence the precipitation in the southern and northern glacier areas of the QTP in the summer monsoon season. The three-dimensional changes of water vapor transport can lead to the difference of water balance between different glacier areas. Under global warming, the northwest QTP is in the ascending branch of the vertical water driven thermally by the tropical Indian Ocean. The warm water vapor from the tropical ocean climbs to the QTP, forming a significant supply effect of precipitation in the northwestern glacier area, which makes the glacier retreat at a relatively slow rate. Meanwhile, the southern and southeastern QTP regions are in the descending branch of vapor transport with the declining trend in the lower troposphere, which lead to the shortage water supply aggravating the glacier loss in the southern and southeastern QTP.


Asunto(s)
Monitoreo del Ambiente , Cubierta de Hielo , Vapor , Calentamiento Global , Océano Índico , Estaciones del Año , Tibet , Clima Tropical
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