9 research outputs found

    Savannahs of Asia: Antiquity, biogeography, and an uncertain future

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    The savannahs of Asia remain locally unrecognized as distinctive ecosystems, and continue to be viewed as degraded forests or seasonally dry tropical forests. These colonial-era legacies are problematic, because they fail to recognize the unique diversity of Asian savannahs and the critical roles of fire and herbivory in maintaining ecosystem health and diversity. In this review, we show that: the palaeo-historical evidence suggests that the savannahs of Asia have existed for at least 1 million years, long before widespread landscape modification by humans; savannah regions across Asia have levels of C4 grass endemism and diversity that are consistent with area-based expectations for non-Asian savannahs; there are at least three distinct Asian savannah communities, namely deciduous broadleaf savannahs, deciduous fine-leafed and spiny savannahs and evergreen pine savannahs, with distinct functional ecologies consistent with fire- and herbivory-driven community assembly. Via an analysis of savannah climate domains on other continents, we map the potential extent of savannahs across Asia. We find that the climates of African savannahs provide the closest analogues for those of Asian deciduous savannahs, but that Asian pine savannahs occur in climates different to any of the savannahs in the southern continents. Finally, we review major threats to the persistence of savannahs in Asia, including the mismanagement of fire and herbivory, alien woody encroachment, afforestation policies and future climate uncertainty associated with the changing Asian monsoon. Research agendas that target these issues are urgently needed to manage and conserve these ecosystems. This article is part of the themed issue ‘Tropical grassy biomes: linking ecology, human use and conservation’

    TEMPERATURE EFFECTS ON THE ASH COLOUR OF FOREST LITTER / TEMPERATŪROS ĮTAKA MIŠKO PAKLOTĖS PELENŲ SPALVAI

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    Research was carried out to identify the influence of temperature (150, 250, 350, 450, 550ºC) on the ash colour of Acer platanoides L. leaf litter and Pinus sylvestris L. needle litter samples collected from deciduous coniferous mixed forest in Lithuania (54º43‘ N 25º19‘ E) in April 2010. To achieve the objective, a laboratory experiment was conducted to determine ash samples using the Munsell Colour Chart. The analysis of colours has demonstrated that considering all litter samples, an increase in the temperature of litter heating was found to increase ash colour values (r = 0.92; p = 0.01). All the samples (n = 50) of both litter species were divided into categories 2.5Y (5 samples), 7.5YR (10 samples) and 10YR (35 samples). The total black Munsell colour was observed at a temperature of 350ºC for both litter species. Needle ash started turning bright at a temperature of 550ºC while the complete consumption of leaf litter was visible at a temperature of 450ºC. We conclude that the Munsell Colour Chart used for predicting the colour of ash is an informative feature to have the primary classification of ash. It is imperative to analyse the colour of the litter ash of the selected tree species in order to quickly and easily assess and predict their possible impact on the surrounding environment. Santrauka Tyrimas atliktas siekiant nustatyti temperatūros įtaką (150, 250, 350, 450, 550 ºC) paprastosios pušies spyglių ir paprastojo klevo lapų, surinktų iš lapuočių ir spygliuočių mišraus miško Lietuvoje (54° 43 „N 25° 19 ‚E) 2010-ųjų balandį, pelenų spalvai. Laboratorijoje Munsell spalvų sistema buvo naudojama, norint nustatyti pelenų spalvos reikšmes. Tyrimas parodė, kad didinant degimo temperatūrą visų pelenų spalvų vertės atitinkamai didėjo (r = 0,92, p = 0,01). Pagal spalvų skalę visus mėginius (50) galima suskirstyti į kategorijas: 2.5Y (5 mėginiai), 7.5YR (10 mėginių) ir 10YR (35 mėginiai). Juoda spalva buvo stebima abiejų rūšių pelenuose, kurie buvo deginami 350 ºC temperatūroje. Spyglių pelenai tapo šviesūs esant 550 ºC temperatūrai, o šviesėjantys lapų pelenai pastebėti 450 ºC temperatūroje. Galime teigti, kad Munsell spalvų sistemos naudojimas pelenų spalvai nustatyti yra informatyvus pirminės pelenų klasifikacijos rodiklis. Raktiniai žodžiai: paprastoji pušis; paprastasis klevas; temperatūra; spalva; paklot

    Wildfires, Ecosystem Services, and Biodiversity in Tropical Dry Forest in India

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