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1.
PhytoKeys ; 246: 1-14, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39183963

RESUMO

A new bamboo species, Yushaniadezhui, from Kunming, Yunnan, China is described and illustrated in this paper. The new species used to be misidentified as Y.polytricha. Based on careful comparison of morphological features and molecular phylogeny evidence, we confirmed its identity as a new member of the genus Yushania. Yushaniadezhui resembles Y.maculata, Y.polytricha and Y.weixiensis in several aspects, such as culm height and branch complement structure. However, the glabrous culm leaf sheaths and internodes, the absence of auricles and oral setae on most foliage leaves, except the one-year-old foliage leaves, the pubescence on the adaxial surface of the one-year-old foliage leaves and its limestone habitat preference can readily distinguish this new species from its related taxa. Moreover, we emphasise that individuals from various populations and molecular markers with different inheritance patterns for phylogeny reconstruction should be included in new species discovery, especially in plant groups with complex evolutionary histories.

2.
Tree Physiol ; 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39030688

RESUMO

Tropical montane evergreen broad-leaved forests cover the majority of forest areas and have high carbon storage in Xishuangbanna, southwest China. However, stem radial growth dynamics and their correlations with climate factors have never been analyzed in this forest type. By combining bi-weekly microcoring and high-resolution dendrometer measurements, we monitored xylogenesis and stem radius variations of the deciduous species Betula alnoides and the evergreen species Schima wallichii. We analyzed the relationships between weekly climate variables prior to sampling and the enlarging zone width or wall thickening zone width, as well as weekly radial increments and climate factors during two consecutive years (2020-2021) showing contrasting hydrothermal conditions in the pre-monsoon season. In the year 2020, which was characterized by a warmer and drier pre-monsoon season, the onset of xylogenesis and radial increments of B. alnoides and S. wallichi were delayed by three months and one month, respectively, compared to the year 2021. In 2020, xylem formation and radial increments were significantly reduced for B. alnoides, but not for S. wallichill. The thickness of enlarging zone and wall thickening zone in S. wallichill were positively correlated with relative humidity, minimum and mean air temperature, but were negatively correlated with vapor pressure deficit during 2020-2021. The radial increments of both species showed significant positive correlations with precipitation and relative humidity, and negative correlations with vapor pressure deficit and maximum air temperature during two years. Our findings reveal that drier pre-monsoon conditions strongly delay growth initiation and reduce stem radial growth, providing deep insights to understand tree growth and carbon sequestration potential in tropical forests under a predicted increase in frequent drought events.

3.
Mycologia ; : 1-17, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38976827

RESUMO

A new and threatened polypore species, Bondarzewia loguerciae, is described from the cloud forests of southern Brazil. It is characterized by single-pileate basidiomata that grow on dead branches and along living stems of standing trunks and present a context with dark lines and resinous tubes. When growing in axenic culture, this species also develops chlamydospores. We provide an illustrated morphological description and molecular analysis. Our specimens from Brazil form a monophyletic group among other species of the Southern Hemisphere. The conservation status of B. loguerciae is assessed and published as "Critically Endangered" based on the International Union for Conservation of Nature  (IUCN) criteria. Additionally, a key to the species is provided.

4.
Ecol Evol ; 14(6): e11436, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38826175

RESUMO

Costa Rica emerged from the seas as a new geological territory during the Miocene as an insular archipelago. It later became part of a continental area once it became a segment of Central America. Two dung beetle genera that colonized this new territory from South and North America, Canthidium and Onthophagus (Coleoptera: Scarabaeidae: Scarabaeinae), are here studied, in the first analysis of a volcanic paleo-archipelago, colonized from its emergence, and then later becoming terra firma. To assess their biodiversity distribution patterns, we analyzed the effect of biogeography, ecosystem origins, and body size on their altitudinal distribution patterns in three geographic basins of Costa Rica. Based on 32 years of collecting representing more than 158,000 specimens from 1017 localities, we undertook Generalized Linear Models of the two dung beetle genera to assess the effects of biodiversity and biogeographical distribution patterns. Canthidium and Onthophagus species ranged from 0 to 3000 m a.s.l., with an abrupt diversity decline at altitudes above 1500 m. Endemic species tended to show a higher altitudinal mean with a narrow altitudinal band distribution than non-endemic dung beetle species. Although there was a trend of decreasing species body size with the increase in altitude, such a trend depended on the distribution pattern of the species group. This possible insular-mediated endemicity mechanism has generated baffling biodiversity levels, considered the highest worldwide per unit area. Costa Rica is an expanse represented by a geographic overlap of two or more temporally disjunct areas and is not part of a natural transition zone. The effect of the insular Miocene origin of Costa Rica still pervades today, reflected by different insular syndromes shown by the dung beetle fauna. The importance of geological origins in generating biodiversity seems to have been an underrated criterion for conservation biology practices and should be considered ex officio.

5.
Data Brief ; 54: 110475, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38756927

RESUMO

The submontane forests in the Congo Basin have not been studied sufficiently in terms of floristic diversity, biomass, and geographic distribution. The region's lack of resources and rugged terrain are among the barriers to sampling biodiversity. This study focuses on two understudied submontane forest areas, Bakossi National Park (BNP) and Mt. Nlonako (MN), which form part of the continental Cameroon Mountains and are believed to have high species diversity and endemism. However, significant gaps exist in biodiversity data across the continental Cameroon Mountains. This study is the first detailed quantitative survey of forests in the BNP and MN through permanent plot sampling. The results of this study can be used to guide policies for managing montane ecosystems in Cameroon and enhancing conservation efforts. The study also provides an opportunity for long-term monitoring of forest health and REDD+ status.

6.
Plants (Basel) ; 13(7)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38611553

RESUMO

The Australian Wet Tropics World Heritage Area (WTWHA) in northeast Queensland is home to approximately 18 percent of the nation's total vascular plant species. Over the past century, human activity and industrial development have caused global climate changes, posing a severe and irreversible danger to the entire land-based ecosystem, and the WTWHA is no exception. The current average annual temperature of WTWHA in northeast Queensland is 24 °C. However, in the coming years (by 2030), the average annual temperature increase is estimated to be between 0.5 and 1.4 °C compared to the climate observed between 1986 and 2005. Looking further ahead to 2070, the anticipated temperature rise is projected to be between 1.0 and 3.2 °C, with the exact range depending on future emissions. We identified 84 plant species, endemic to tropical montane cloud forests (TMCF) within the WTWHA, which are already experiencing climate change threats. Some of these plants are used in herbal medicines. This study comprehensively reviewed the metabolomics studies conducted on these 84 plant species until now toward understanding their physiological and metabolomics responses to global climate change. This review also discusses the following: (i) recent developments in plant metabolomics studies that can be applied to study and better understand the interactions of wet tropics plants with climatic stress, (ii) medicinal plants and isolated phytochemicals with structural diversity, and (iii) reported biological activities of crude extracts and isolated compounds.

7.
Am J Bot ; 111(5): e16322, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38641895

RESUMO

PREMISE: Functional traits reflect species' responses to environmental variation and the breadth of their ecological niches. Fagus grandifolia and Oreomunnea mexicana have restricted distribution in upper montane cloud forests (1700-2000 m a.s.l.) in Mexico. These species were introduced into plantings at lower elevations (1200-1600 m a.s.l.) that have climates predicted for montane forests in 2050 and 2070. The aim was to relate morphological leaf traits to the ecological niche structure of each species. METHODS: Leaf functional traits (leaf area, specific leaf area [SLA], thickness, and toughness) were analyzed in forests and plantings. Atmospheric circulation models and representative concentration pathways (RCPs: 2.6, 4.5, 8.5) were used to assess future climate conditions. Trait-niche relationships were analyzed by measuring the Mahalanobis distance (MD) from the forests and the plantings to the ecological niche centroid (ENC). RESULTS: For both species, leaf area and SLA were higher and toughness lower in plantings at lower elevation relative to those in higher-elevation forests, and thickness was similar. Leaf traits varied with distance from sites to the ENC. Forests and plantings have different environmental locations regarding the ENC, but forests are closer (MD 0.34-0.58) than plantings (MD 0.50-0.70) for both species. CONCLUSIONS: Elevation as a proxy for expected future climate conditions influenced the functional traits of both species, and trait patterns related to the structure of their ecological niches were consistent. The use of distances to the ENC is a promising approach to explore variability in species' functional traits and phenotypic responses in optimal versus marginal environmental conditions.


Assuntos
Mudança Climática , Fagus , Florestas , Folhas de Planta , Folhas de Planta/fisiologia , Folhas de Planta/anatomia & histologia , Fagus/fisiologia , Fagus/anatomia & histologia , México , Ecossistema
8.
Animals (Basel) ; 14(8)2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38672388

RESUMO

Understanding the spatial variation and formation mechanism of biological diversity is a hot topic in ecological studies. Comparing with α diversity, ß diversity is more accurate in reflecting community dynamics. During the past decades, ß diversity studies usually focused on plants, mammals, and birds. Studies of amphibian ß diversity in montane ecosystems, in particular, tadpoles, are still rare. In this study, Mount Emei, located in southwestern China, was selected as the study area. We explored the tadpole ß diversity in 18 streams, based on a two-year survey (2018-2019). Our results indicated a high total ß diversity in tadpole assemblages, which was determined by both turnover and nestedness processes, and the dominant component was turnover. Both the total ß diversity and turnover component were significantly and positively correlated with geographical, elevational, and environmental distances, but no significant relationship was detected between these and the nestedness component. Moreover, the independent contributions of river width, current velocity, and chlorophyll α were larger than that of geographical and elevational distance. Overall, tadpole ß diversity was determined by both spatial and environmental factors, while the contribution of environmental factors was larger. Future studies can focus on functional and phylogenetic structures, to better understand the tadpole assembly process.

9.
PeerJ ; 12: e17067, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38500522

RESUMO

Canopy structure and understory light have important effects on forest productivity and the growth and distribution of the understory. However, the effects of stand composition and season on canopy structure and understory light environment (ULE) in the subtropical mountain Pinus massoniana forest system are poorly understood. In this study, the natural secondary P. massoniana-Castanopsis eyrei mixed forest (MF) and P. massoniana plantation forest (PF) were investigated. The study utilized Gap Light Analyzer 2.0 software to process photographs, extracting two key canopy parameters, canopy openness (CO) and leaf area index (LAI). Additionally, data on the transmitted direct (Tdir), diffuse (Tdif), and total (Ttot) radiation in the light environment were obtained. Seasonal variations in canopy structure, the ULE, and spatial heterogeneity were analyzed in the two P. massoniana forest stands. The results showed highly significant (P < 0.01) differences in canopy structure and ULE indices among different P. massoniana forest types and seasons. CO and ULE indices (Tdir, Tdif, and Ttot) were significantly lower in the MF than in the PF, while LAI was notably higher in the MF than in the PF. CO was lower in summer than in winter, and both LAI and ULE indices were markedly higher in summer than in winter. In addition, canopy structure and ULE indices varied significantly among different types of P. massoniana stands. The LAI heterogeneity was lower in the MF than in the PF, and Tdir heterogeneity was higher in summer than in winter. Meanwhile, canopy structure and ULE indices were predominantly influenced by structural factors, with spatial correlations at the 10 m scale. Our results revealed that forest type and season were important factors affecting canopy structure, ULE characteristics, and heterogeneity of P. massoniana forests in subtropical mountains.


Assuntos
Fagaceae , Pinus , Estações do Ano , Florestas , Folhas de Planta
10.
Trends Ecol Evol ; 39(4): 318-319, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38461120

RESUMO

Previous studies demonstrated decreasing body size of birds in response to rising temperatures. Recently, Neate-Clegg et al. documented that birds have been becoming larger in an Afromontane forest over four decades. This highlights the complexity of morphological responses to climate, the importance of context, and the need to study phenomena in a diversity of regions.


Assuntos
Mudança Climática , Florestas , Animais , Aves , Tamanho Corporal , Temperatura
11.
Ecol Evol ; 14(2): e10893, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38314313

RESUMO

The Guizhou golden monkey (Rhinopithecus brelichi) is a critically endangered wildlife species, and understanding its diet composition may be useful for assessing its feeding strategies. DNA metabarcoding was used to determine the dietary diversity of R. brelichi. DNA was extracted from 31 faecal samples and amplified chloroplast rbcL and mitochondrial COI DNA was sequenced using the Illumina NovaSeq platform. A comparative analysis of the sequences revealed that the five most abundant plant genera were Magnolia, Morinda, Viburnum, Tetradium and Eurya. In winter, R. brelichi mostly consumed shrubs, herbs and shrubs/trees according to the habit of plant genera with higher abundances comparatively. The five most abundant families in animal diet were Psychodidae, Trichinellidae, Staphylinidae, Scarabaeidae and Trichoceridae. This study is the first to show the composition of the winter animal diets of R. brelichi based on DNA metabarcoding. These results provide an important basis for understanding the diet of wild R. brelichi, which inhabits only the Fanjingshan National Nature Reserve, China.

12.
Ecol Evol ; 14(1): e10738, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38235410

RESUMO

Montane birds experience a range of challenges that may limit their breeding success, including nest predation and severe climactic conditions. The continuing effects of climate change are causing shifts in biotic and abiotic factors that may compound these threats to montane bird species. In northeastern montane forests, many bird species are shifting downslope, potentially as the result of increased precipitation and temperature at higher elevations. Although lower elevations might be more favorable in terms of climactic conditions, nest predation is higher at lower elevations. Thus, montane birds might be faced with the opposing pressures of adverse climactic conditions at higher elevations and increased predation at lower elevations. We monitored nests of Swainson's Thrush (Catharus ustulatus) along an elevation gradient in the White Mountain National Forest in New Hampshire in 2016, 2018, 2019, and 2021 to examine the effect of biotic and abiotic factors on daily nest survival rate (DSR). Linear time explained the most variation of DSR in AICc model comparison, indicating that DSR decreases across the breeding season. Rain intensity (mm/h) had a weak negative effect on DSR, indicating that heavier rain per hour decreases Swainson's Thrush DSR. Moreover, we found some support for a negative interaction effect of elevation in conjunction with minimum daily temperature: DSR of Swainson's Thrush nests at low elevations (281 m) increased with increasing minimum daily temperatures and decreased at high elevations with increasing minimum daily temperatures. Our results suggest nesting survival of montane breeding birds may be at risk as heavier precipitation events become more frequent and intense due to the changing climate and raises the possibility that other passerine species could be at risk in this system.

13.
Sci Justice ; 64(1): 73-80, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38182315

RESUMO

Forensic palynology is a tool in criminalistics that uses spores and pollen grains to link a certain geographical location with a crime scene. The comparison of the pollen assemblage of a crime-scene soil and that of footwear of suspects and victims proved to be very useful as judicial evidence in multiple environments with marked seasonality. However, its usefulness in non-seasonal high-altitude soils has not been experimentally evaluated to the same extent. For this reason, the present study addressed this information gap by undertaking a palynological study in areas with high crime rates in the city of La Paz, Bolivia. To do this, we carried out multiple experimental samplings in three locations with different types of soil and different degrees of urbanization. Specifically, we compared whether the vegetation present at the time of taking the reference samples, was reflected in the pollen rain. Results showed that the vast majority of the species present in the vegetation were found in the pollen rain, with the exception of some plant species with entomophilous pollination syndrome. We also show that the transfer between assemblages from pollen rain to footwear happened effectively, which helped identify their geographical origin, and unveiled a great number of useful indicator species.


Assuntos
Altitude , Pólen , Humanos , Crime , Projetos de Pesquisa , Solo
14.
Rev. peru. biol. (Impr.) ; 31(1): e25588, Jan.-Mar. 2024. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1565769

RESUMO

Resumen Se reporta por primera vez la presencia del tigrillo u ocelote (Leopardus pardalis), en el Santuario Histórico de Machupicchu, mediante el uso de cámaras trampa. Se obtuvieron 21 registros fotográficos independientes en cuatro sectores de bosque montano entre junio de 2018 y marzo del 2020. El rango altitudinal registrado para esta especie dentro del Santuario comprende desde 2193 hasta 3414 metros de altitud, lo que incluye el segundo registro a mayor elevación en el Perú. Los registros indican un patrón de actividad catemeral, es decir sin ninguna preferencia de actividad horaria entre el día y la noche, y sugieren que la presencia de tigrillo en algunas áreas a más de 3000 m puede ser más común de lo que se pensaba, con ejemplares presentes todo el año.


Abstract We report for the first time the presence of the ocelot (Leopardus pardalis), in the Machupicchu Historic Sanctuary, using camera traps. Twenty-one independent photographic records were obtained in four montane forest sectors between June 2018 and March 2020. The altitudinal range recorded for this species within the Sanctuary ranges from 2193 to 3414 m of altitude, which includes the second highest elevation record in Peru. The records indicate a pattern of cathemeral activity, with no time preference between day and night, and suggest that the presence of ocelots in some areas above 3000 m may be more common than previously thought, with specimens present year-round.

15.
Plant Cell Environ ; 47(3): 731-750, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38047584

RESUMO

Tropical montane forests (TMFs) are biodiversity hotspots and provide vital ecosystem services, but they are disproportionately vulnerable to climate warming. In the Andes, cold-affiliated species from high elevations are being displaced at the hot end of their thermal distributions by warm-affiliated species migrating upwards from lower elevations, leading to compositional shifts. Leaf functional traits are strong indicators of plant performance and at the community level have been shown to vary along elevation gradients, reflecting plant adaptations to different environmental niches. However, the plastic response of such traits to relatively rapid temperature change in Andean TMF species remains unknown. We used three common garden plantations within a thermosequence in the Colombian Andes to investigate the warming and cooling responses of key leaf functional traits in eight cold- and warm-affiliated species with variable thermal niches. Cold-affiliated species shifted their foliar nutrient concentrations when exposed to warming, while all other traits did not significantly change; contrastingly, warm-affiliated species were able to adjust structural, nutrient and water-use efficiency traits from acquisitive to conservative strategies in response to cooling. Our findings suggest that cold-affiliated species will struggle to acclimate functional traits to warming, conferring warm-affiliated species a competitive advantage under climate change.


Assuntos
Ecossistema , Árvores , Árvores/fisiologia , Clima Tropical , Florestas , Folhas de Planta/fisiologia
16.
Sci Total Environ ; 912: 168798, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38016557

RESUMO

Lake browning is widespread due to increased supply of dissolved organic carbon under climate warming and nitrogen deposition. However, multitrophic level responses to lake browning are poorly understood. Our study aims to explore such responses across multitrophic levels based on sedimentary records of diatoms, chrysophyte stomatocysts and chironomids in a remote headwater lake in the Three Gorges Reservoir region, central China. Although all biotic proxies were analysed in the same core, the timing of shifts in chironomids (1886 ± 18 CE) preceded that in chrysophyte stomatocysts (∼1914 ± 10 CE) and diatoms (∼1941 ± 6 CE). Shifts in biotic communities were closely linked to rising temperature, δ15N depletion (a proxy for nitrogen deposition), δ13C enrichment (a proxy for littoral moss expansion), as well as biotic interactions, whereas the relative importance of the driving forces varied among the three biotic groups. Our results suggest that the zoobenthos grazing effect might be more important than bottom-up pathways in humic environments. Additionally, the coexistence of benthic, littoral and pelagic algae after the 1950s suggested that mixotrophic chrysophytes could reduce lake browning through heterotrophic processes and sustain the ecological equilibrium between littoral, pelagic and benthic productivity. Therefore, lake browning ecosystem regime shifts require analyses of multiple trophic levels. Our results suggest that heterotrophy may become more important in lake ecosystem carbon cycling with water brownification in Mulong Lake, as well as similar montane lakes.


Assuntos
Diatomáceas , Resiliência Psicológica , Lagos , Ecossistema , Plantas , Nitrogênio
17.
Rev. biol. trop ; 71(1)dic. 2023.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1449509

RESUMO

Introducción: Los bosques de niebla se caracterizan por su distribución insular en sistemas montañosos tropicales. Florísticamente son complejos y heterogéneos, y con vacíos de información que afectan la comprensión de cómo varía su diversidad y estructura. Objetivo: Analizar los patrones de diversidad, estructura y composición del bosque de niebla en México. Métodos: Contamos y medimos plantas leñosas en 40 parcelas de 0.1 ha de cinco sitios en aproximadamente 200 km a lo largo de la Sierra Madre de Chiapas, México (1 700 - 2 100 m.s.n.m.). Usamos tres métodos estadísticos: análisis de varianza (diversidad verdadera y estructura entre sitios), regresión simple y métodos multivariados (clima y elevación). Resultados: Registramos 4 021 individuos (220 especies, 60 familias). En la diversidad verdadera, solo encontramos diferencias en riqueza de especies, con un ligero incremento hacia la parte central del área. La diversidad fue constante para especies comunes y dominantes. No encontramos diferencias en la densidad de árboles o área basal entre los sitios. Sin embargo, hubo menor densidad y mayor área basal a mayores elevaciones. La diversidad beta y la diferenciación en la composición florística es alta e importante entre las parcelas de un mismo sitio y se incrementa con la distancia entre los sitios. Conclusiones: La diversidad beta y la diferenciación florística contribuyen significativamente en la variación del bosque de niebla. Las variables climáticas y la altitud tienen efectos distintos sobre la diversidad y estructura.


Introduction: Cloud forests are noted for their narrow distribution in tropical mountain systems. Floristically, they are complex and heterogeneous, with gaps in information that hinder the understanding of how their diversity and structure vary. Objective: To analyze patterns of diversity, structure, and composition of the cloud forest in Mexico. Methods: We counted and measured woody plants in forty 0.1 ha plots from five sites in approximately 200 km along the Sierra Madre of Chiapas, Mexico (1 700 - 2 100 m.a.s.l.). We used three statistical methods: analysis of variance (diversity true and structure among sites), simple regression and multivariate statistics (climate and elevation). Results: We recorded 4 021 individuals (220 species, 60 families). In true diversity, we only found differences for species richness, with a slight increase toward the central part of the area. Diversity was constant for common and dominant species. We found no differences in tree density or basal area between sites. However, there was less density and more basal area at higher elevations. Beta diversity and differentiation in floristic composition are high and important between plots of the same site, and they increase with distance between sites. Conclusions: Beta diversity and floristic differentiation significantly contribute to variation in the cloud forest. Climatic variables and altitude have different effects on diversity and structure.

18.
Front Plant Sci ; 14: 1276424, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38023915

RESUMO

Wood density (WD) is a key functional trait related to ecological strategies and ecosystem carbon dynamics. Despite its importance, there is a considerable lack of information on WD in tropical Andean forests, particularly regarding its relationship with forest succession and ecosystem carbon cycling. Here, we quantified WD in 86 upper Andean tree and shrub species in central Colombia, with the aim of determining how WD changes with forest succession and how it is related to productivity. We hypothesized that WD will increase with succession because early successional forests will be colonized by acquisitive species, which typically have low WD, while the shaded understory of older forests should favor higher WD. We measured WD in 481 individuals from 27 shrub and 59 tree species, and quantified aboveground biomass (AGB), canopy height, net primary production (NPP) and species composition and abundance in 14, 400-m2, permanent plots. Mean WD was 0.513 ± 0.114 (g/cm3), with a range between 0.068 and 0.718 (g/cm3). Shrubs had, on average, higher WD (0.552 ± 0.095 g/cm3) than trees (0.488 ± 0.104 g/cm3). Community weighted mean WD (CWMwd) decreased with succession (measured as mean canopy height, AGB, and basal area); CWMwd also decreased with aboveground NPP and stem growth. In contrast, the percentage of NPP attributed to litter and the percent of shrubs in plots increased with CWMwd. Thus, our hypothesis was not supported because early successional forests had higher CWMwd than late successional forests. This was related to a high proportion of shrubs (with high WD) early in succession, which could be a consequence of: 1) a low seed availability of trees due to intense land use in the landscape and/or 2) harsh abiotic conditions early in succession that filter out trees. Forest with high CWMwd had a high %NPP attributed to litter because they were dominated by shrubs, which gain little biomass in their trunks. Our findings highlight the links between WD, succession and carbon cycling (biomass and productivity) in this biodiversity hotspot. Thus, WD is an important trait that can be used to understand upper Andean forest recovery and improve forest restoration and management practices.

19.
Ann Bot ; 132(4): 699-715, 2023 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-37897046

RESUMO

BACKGROUND AND SCOPE: Vascular epiphytes have a variety of mechanisms to trap and retain water, including crassulacean acid metabolism (CAM). Niche segregation was investigated for epiphytic bromeliads on the tropical Caribbean island of Trinidad, where habitats range from lowland deciduous forests to high-rainfall montane tropical forests, ~1000 m in elevation. METHODS: Four tank-impounding bromeliad epiphytes in the genus Aechmea (Ae. aquilega, Ae. fendleri, Ae. nudicaulis and Ae. dichlamydea) with CAM were mapped across their distinct geographical and elevational zonations in northern Trinidad and Tobago. Species distribution modelling was used to determine environmental limitations for each species. Anatomical and physiological measurements included leaf succulence traits, gas exchange and CAM activity; hydraulic conductance and vulnerability; stomatal sensitivity and quantum yield responses to nocturnal temperature and long-term water deficits. KEY RESULTS: A total of 2876 field observations identified the transitions between the lowland Ae. aquilega and montane Ae. fendleri, occurring >500 m a.s.l. at the drier western end of the Northern Mountain Range and at progressively lower elevations towards the wetter, eastern region. Anatomical and physiological sensitivities of gas exchange, CAM activity and water use, and responses to elevated nocturnal temperatures and drought, were markedly different for Ae. fendleri compared with Ae. aquilega or the ubiquitous Ae. nudicaulis. CONCLUSIONS: The species distribution model highlighted the susceptibility of Ae. fendleri to a changing climate. For each species, physiological and anatomical traits were tailored to environmental tolerances, consistent with specialist or generalist niche preferences. Using Intergovernmental Panel on Climate Change scenarios, we predict that rapid rainfall and temperature changes will lead to the loss of Ae. fendleri and associated lower (and upper) montane forest communities from Trinidad, seriously impacting both biodiversity and critical ecosystem functions here and in other tropical island habitats. Epiphytic bromeliads act as markers for threatened communities, and their physiological tolerances represent key indicators of climate change impacts.


Assuntos
Metabolismo Ácido das Crassuláceas , Ecossistema , Mudança Climática , Florestas , Água/metabolismo , Clima Tropical
20.
Rev. peru. biol. (Impr.) ; 30(4)oct. 2023.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1530341

RESUMO

We present a list of bats collected above 2000 meters in Río Abiseo National Park. Sixteen bat species belonging to the Phyllostomidae and Vespertilionidae families were collected during four expeditions between 1987 and 1990. Twelve species were found within expected altitudinal ranges, but four exceeded their previously reported maximum altitudinal ranges. A comparison with other bat lists from other localities at similar altitudes is presented.


Se presenta una lista de murciélagos colectados por encima de los 2000 m en el Parque Nacional Río Abiseo. Dieciséis especies de murciélagos pertenecientes tanto a las familias Phyllostomidae y Vespertilionidae fueron colectadas durante cuatro expediciones realizadas entre 1987 y 1990. Doce especies fueron encontradas dentro de los rangos altitudinales esperados, pero cuatro excedieron su altitud máxima previamente reportada. Se presenta una comparación con otras listas de murciélagos de otras localidades a altitudes similares.

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