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2.
Int J Biometeorol ; 67(5): 913-925, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37010574

RESUMEN

Climate change has significantly impacted vegetation phenology across the globe with vegetation experiencing an advance in the spring green-up phases and a delay in fall senescence. However, some studies from high latitudes and high elevations have instead shown delayed spring phenology, owing to a lack of chilling fulfillment and altered snow cover and photoperiods. Here we use the MODIS satellite-derived view-angle corrected surface reflectance data (MCD43A4) to document the four phenological phases in the high elevations of the Sikkim Himalaya and compared the phenological trends between below-treeline zones and above-treeline zones. This analysis of remotely sensed data for the study period (2001-2017) reveals considerable shifts in the phenology of the Sikkim Himalaya. Advances in the spring start of the season phase (SOS) were more pronounced than delays in the dates for maturity (MAT), senescence (EOS), and advanced dormancy (DOR). The SOS significantly advanced by 21.3 days while the MAT and EOS were delayed by 15.7 days and 6.5 days respectively over the 17-year study period. The DOR showed an advance of 8.2 days over the study period. The region below the treeline showed more pronounced shifts in phenology with respect to an advanced SOS and a delayed EOS and DOR that above treeline. The MAT, however, showed a greater delay in the zone above the treeline than below. Lastly, unlike other studies from high elevations, there is no indication that winter chilling requirements are driving the spring phenology in this region. We discuss four possible explanations for why vegetation phenology in the high elevations of the Eastern Himalaya may exhibit trends independent of chilling requirements and soil moisture due to mediation by snow cover.


Asunto(s)
Cambio Climático , Nieve , Estaciones del Año , Temperatura
3.
Proc Biol Sci ; 289(1973): 20212650, 2022 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-35473372

RESUMEN

The collection of caterpillar fungus accounts for 50-70% of the household income of thousands of Himalayan communities and has an estimated market value of $5-11 billion across Asia. However, Himalayan collectors are at multiple economic disadvantages compared with collectors on the Tibetan Plateau because their product is not legally recognized. Using a customized hybrid-enrichment probe set and market-grade caterpillar fungus (with samples up to 30 years old) from 94 production zones across Asia, we uncovered clear geography-based signatures of historical dispersal and significant isolation-by-distance among caterpillar fungus hosts. This high-throughput approach can readily distinguish samples from major production zones with definitive geographical resolution, especially for samples from the Himalayan region that form monophyletic clades in our analysis. Based on these results, we propose a two-step procedure to help local communities authenticate their produce and improve this multi-national trade-route without creating opportunities for illegal exports and other forms of economic exploitation. We argue that policymakers and conservation practitioners must encourage the fair trade of caterpillar fungus in addition to sustainable harvesting to support a trans-boundary conservation effort that is much needed for this natural commodity in the Himalayan region.


Asunto(s)
Hongos , Asia , Geografía
5.
Ambio ; 51(6): 1474-1484, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34962639

RESUMEN

As the two largest countries by population, China and India have pervasive effects on the ecosphere. Because of their human population size and long international boundary, they share biodiversity and the threats to it, as well as crops, pests and diseases. We ranked the two countries on a variety of environmental challenges and solutions, illustrating quantitatively their environmental footprint and the parallels between them regarding the threats to their human populations and biodiversity. Yet we show that China and India continue to have few co-authorships in environmental publications, even as their major funding for scientific research has expanded. An agenda for collaboration between China and India can start with the shared Himalaya, linking the countries' scientists and institutions. A broader agenda can then be framed around environmental challenges that have regional patterns. Coordinated and collaborative research has the potential to improve the two countries' environmental performance, with implications for global sustainability.


Asunto(s)
Ciencia Ambiental , Biodiversidad , China , Humanos , India
6.
Science ; 374(6563): 42, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34591634

RESUMEN

A history of tropical ecosystems emphasizes the importance of including human inhabitants in conservation conversations.

7.
Curr Biol ; 31(16): 3671-3677.e3, 2021 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-34237267

RESUMEN

Most new infectious diseases emerge when pathogens transfer from animals to humans.1,2 The suspected origin of the COVID pandemic in a wildlife wet market has resurfaced debates on the role of wildlife trade as a potential source of emerging zoonotic diseases.3-5 Yet there are no studies quantitatively assessing zoonotic disease risk associated with wildlife trade. Combining data on mammal species hosting zoonotic viruses and mammals known to be in current and future wildlife trade,6 we found that one-quarter (26.5%) of the mammals in wildlife trade harbor 75% of known zoonotic viruses, a level much higher than domesticated and non-traded mammals. The traded mammals also harbor distinct compositions of zoonotic viruses and different host reservoirs from non-traded and domesticated mammals. Furthermore, we highlight that primates, ungulates, carnivores, and bats represent significant zoonotic disease risks as they host 132 (58%) of 226 known zoonotic viruses in present wildlife trade, whereas species of bats, rodents, and marsupials represent significant zoonotic disease risks in future wildlife trade. Thus, the risk of carrying zoonotic diseases is not equal for all mammal species in wildlife trade. Overall, our findings strengthen the evidence that wildlife trade and zoonotic disease risks are strongly associated, and that mitigation measures should prioritize species with the highest risk of carrying zoonotic viruses. Curbing the sales of wildlife products and developing principles that support the sustainable and healthy trade of wildlife could be cost-effective investments given the potential risk and consequences of zoonotic outbreaks.


Asunto(s)
Animales Salvajes/virología , Comercio , Mamíferos/virología , Pandemias/prevención & control , Zoonosis/transmisión , Animales , Reservorios de Enfermedades/veterinaria , Reservorios de Enfermedades/virología , Humanos , Desarrollo Sostenible , Zoonosis/epidemiología , Zoonosis/prevención & control , Zoonosis/virología
10.
PhytoKeys ; 163: 1-560, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-37397271

RESUMEN

A checklist of the grasses of India is presented, as compiled from survey of all available literature. Of the twelve subfamilies of grasses, ten are represented in India. Most subfamilies have been examined by taxonomic experts for up-to-date nomenclature. The list includes 1506 species plus infraspecific taxa and presents information on types, synonyms, distribution within India, and habit. Twelve new combinations are made, viz. Arctopoa tibetica (Munro ex Stapf) Prob. var. aristulata (Stapf) E.A. Kellogg, comb. nov.; Chimonocalamus nagalandianus (H.B. Naithani) L.G. Clark, comb. nov.; Chionachne digitata (L.f.) E.A. Kellogg, comb. nov.; Chionachne wallichiana (Nees) E.A. Kellogg, comb. nov.; Dinebra polystachyos (R. Br.) E.A. Kellogg, comb. nov.; Moorochloa eruciformis (Sm.) Veldkamp var. divaricata (Basappa & Muniv.) E.A. Kellogg, comb. nov.; Phyllostachys nigra (Lodd. ex Lindl.) Munro var. puberula (Miq.) Kailash, comb. & stat. nov.; Tzveleviochloa schmidii (Hook. f.) E.A. Kellogg, comb. nov.; Urochloa lata (Schumach.) C.E. Hubb. var. pubescens (C.E. Hubb.) E.A. Kellogg, comb. nov.; Urochloa ramosa (L.) T.Q. Nguyen var. pubescens (Basappa & Muniy.) E.A. Kellogg, comb. nov.; Urochloa semiundulata (Hochst. ex A. Rich.) Ashalatha & V.J. Nair var. intermedia (Basappa & Muniy.) E.A. Kellogg, comb. nov.

11.
Ann Bot ; 123(1): 181-190, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30165602

RESUMEN

Background and Aims: Kin selection theory predicts that a parent may minimize deleterious effects of competition among seeds developing within ovaries by increasing the genetic relatedness of seeds within an ovary. Alternatively, the number of developing seeds could be reduced to one or a few. It has also been suggested that single or few seeded fruits may be correlated with small flowers, and multi-ovulate ovaries or many seeded fruits may be associated with large flowers with specialized pollination mechanisms. We examined the correlation between flower size and seed number in 69 families of monocotyledons to assess if correlations are significant and independent of phylogeny. Methods: We first examined the effect of phylogenetic history on the evolution of these two traits, flower size and seed number, and then mapped correlations between them on the latest phylogenetic tree of monocotyledons. Results: The results provide phylogenetically robust evidence of strong correlated evolution between flower size and seed number and show that correlated evolution of traits is not constrained by phylogenetic history of taxa. Moreover, the two character combinations, small flowers and a single or few seeds per fruit, and large flowers and many seeded fruits, have persisted in monocotyledons longer than other trait combinations. Conclusions: The analyses support the suggestion that most angiosperms may fall into two categories, one with large flowers and many seeded fruits and the other with small flowers and single or few seeded fruits, and kin selection within ovaries may explain the observed patterns.


Asunto(s)
Evolución Biológica , Flores/anatomía & histología , Magnoliopsida/anatomía & histología , Magnoliopsida/fisiología , Semillas/fisiología , Flores/crecimiento & desarrollo , Magnoliopsida/crecimiento & desarrollo , Filogenia
14.
Proc Natl Acad Sci U S A ; 113(44): 12337-12340, 2016 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-27803372
15.
Proc Biol Sci ; 283(1842)2016 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-27852800

RESUMEN

Competition among developing seeds and sibling rivalry within multiovulated ovaries can be deleterious for both the maternal parent and the siblings. Increased genetic relatedness of seeds within the ovary may foster kin selection and reduce the deleterious consequences of sibling competition. The pollen parent may also be selected for siring all progeny within a fruit. I propose a series of hypotheses to explain the evolution of a number of reproductive traits in angiosperms in the context of kin selection and sibling rivalry within the ovaries of angiosperms. I present evidence to show that a single-pollen parent, indeed, often sires seeds within multiovulated ovaries. Various types of pollen aggregations and transfer of such pollen masses to the stigmas of flowers by specialized pollinators make this increased genetic relatedness possible. An alternative mode to reduce sibling rivalry may be the reduction of ovule number to one, an evolutionary trend that has independently occurred many times in flowering plants. Finally, I build on previously established correlations to predict two sets of correlations among reproductive traits. In the first case, large showy flowers, transfer of pollen en masse by specialized pollinators, and multiovulated ovaries and multisided fruits seem to be correlated. In the second case, the previously established correlations among small and inconspicuous flowers, pollination by wind, water or generalist insects, flowers and fruits with few or single ovules and seeds, respectively, may also include monoecy or dioecy. Although correlations among many of these traits have been established in the past, I invoke kin selection and sibling competition to explain the evolution of correlated traits as two distinct evolutionary pathways in angiosperms.


Asunto(s)
Evolución Biológica , Fenómenos Fisiológicos de las Plantas , Plantas/genética , Polinización , Semillas/genética , Flores/genética , Fenotipo , Polen/genética , Reproducción
16.
PLoS One ; 9(9): e106405, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25180515

RESUMEN

Climate change has already impacted ecosystems and species and substantial impacts of climate change in the future are expected. Species distribution modeling is widely used to map the current potential distribution of species as well as to model the impact of future climate change on distribution of species. Mapping current distribution is useful for conservation planning and understanding the change in distribution impacted by climate change is important for mitigation of future biodiversity losses. However, the current distribution of Chinese caterpillar fungus, a flagship species of the Himalaya with very high economic value, is unknown. Nor do we know the potential changes in suitable habitat of Chinese caterpillar fungus caused by future climate change. We used MaxEnt modeling to predict current distribution and changes in the future distributions of Chinese caterpillar fungus in three future climate change trajectories based on representative concentration pathways (RCPs: RCP 2.6, RCP 4.5, and RCP 6.0) in three different time periods (2030, 2050, and 2070) using species occurrence points, bioclimatic variables, and altitude. About 6.02% (8,989 km2) area of the Nepal Himalaya is suitable for Chinese caterpillar fungus habitat. Our model showed that across all future climate change trajectories over three different time periods, the area of predicted suitable habitat of Chinese caterpillar fungus would expand, with 0.11-4.87% expansion over current suitable habitat. Depending upon the representative concentration pathways, we observed both increase and decrease in average elevation of the suitable habitat range of the species.


Asunto(s)
Cambio Climático , Ecosistema , Hongos/fisiología , Altitud , Animales , China , Geografía , Larva/microbiología , Nepal
18.
PLoS One ; 7(5): e36741, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22615804

RESUMEN

BACKGROUND: Climate change in the Himalayas, a biodiversity hotspot, home of many sacred landscapes, and the source of eight largest rivers of Asia, is likely to impact the well-being of ~20% of humanity. However, despite the extraordinary environmental, cultural, and socio-economic importance of the Himalayas, and despite their rapidly increasing ecological degradation, not much is known about actual changes in the two most critical climatic variables: temperature and rainfall. Nor do we know how changes in these parameters might impact the ecosystems including vegetation phenology. METHODOLOGY/PRINCIPAL FINDINGS: By analyzing temperature and rainfall data, and NDVI (Normalized Difference Vegetation Index) values from remotely sensed imagery, we report significant changes in temperature, rainfall, and vegetation phenology across the Himalayas between 1982 and 2006. The average annual mean temperature during the 25 year period has increased by 1.5 °C with an average increase of 0.06 °C yr(-1). The average annual precipitation has increased by 163 mm or 6.52 mmyr(-1). Since changes in temperature and precipitation are immediately manifested as changes in phenology of local ecosystems, we examined phenological changes in all major ecoregions. The average start of the growing season (SOS) seems to have advanced by 4.7 days or 0.19 days yr(-1) and the length of growing season (LOS) appears to have advanced by 4.7 days or 0.19 days yr(-1), but there has been no change in the end of the growing season (EOS). There is considerable spatial and seasonal variation in changes in climate and phenological parameters. CONCLUSIONS/SIGNIFICANCE: This is the first time that large scale climatic and phenological changes at the landscape level have been documented for the Himalayas. The rate of warming in the Himalayas is greater than the global average, confirming that the Himalayas are among the regions most vulnerable to climate change.


Asunto(s)
Cambio Climático , Ecosistema , India
19.
Science ; 335(6076): 1573, 2012 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-22461593

Asunto(s)
Investigación , Ciencia
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