Net primary productivity and species diversity of herbaceous vegetation of banj-oak （Quercus leucotrichophora A. Camus） forest in Kumaun Himalaya, India were analyzed. Across different growth forms （tall forbs, sho...Net primary productivity and species diversity of herbaceous vegetation of banj-oak （Quercus leucotrichophora A. Camus） forest in Kumaun Himalaya, India were analyzed. Across different growth forms （tall forbs, short forbs, cushion and spreading forbs, grasses）, short forbs were most dominant component during rainy season （1VI=152） and winter season （IVI=167） and grasses during the winter season （IVI=148）. Maximum above-ground production occurred during rainy season （132.5 g m-2） and minimum during winter season （2.8 g m-~）. Below-ground production was maximum （85.9 g m-x） during winter season and minimum （14.9 g m-x） during summer season. Annual net shoot production was 15o g m-~ and below-ground production was 138 g m-~. Of the total input 61% was channeled to above- ground parts and 39% to below-ground parts.展开更多
The experiment was conducted during the short dry and the short rainy seasons in 2008. A botanical inventory and relative frequencies of forage selected by Djallonke sheep grazing were developed by observation and han...The experiment was conducted during the short dry and the short rainy seasons in 2008. A botanical inventory and relative frequencies of forage selected by Djallonke sheep grazing were developed by observation and hand-plucking. Chemical composition and in vitro organic matter digestibility （IVOMD） of hand-plucked material was determined. From July to October, woody plants are a major component of the sheep diet. Sheep selected 40 woody plants and 21 species of herbaceous. During the dry season, grazing occurred more frequently in the fallows. The most frequent woody species belonged to Elaeis guineensis and Fagara zanthoxyloides. At the rainy season, a high proportion of Panicum maximum and Eleucine indica were sampled. Crude protein was high in woody leaves at the dry season. Crude fibre were more variable in herbaceous than in woody and herbaceous were generally higher in the levels of fibre. Chromolaena odorata, Citrus sinensis, Vitex doniana were very high in IVOMD. Spondias mombin, Moringa oleifera, Persea americana, Psidium guajava, Dialium guineense presented lowest values in IVOMD. Among herbaceous, Andropogon gayanus and Panicum maximum still presented a high value of IVOMD at the dry season. High proteins suggest woody with potential as nitrogen supplements to ruminants fed low quality forage during the dry season.展开更多
In the Eurasian forest-steppe,with increasing aridity,the balance between naturally co-existing forest and grassland patches is expected to shift towards grassland dominance in the long run,although feedback mechanism...In the Eurasian forest-steppe,with increasing aridity,the balance between naturally co-existing forest and grassland patches is expected to shift towards grassland dominance in the long run,although feedback mechanisms and changes in land-use may alter this process.In this study,we compared old and recent aerial photographs of Hungarian forest-steppes to find out whether and how the forest proportion and the number of forest patches change at the decadal time scale.The percentage area covered by forest significantly increased in all study sites.The observed forest encroachment may be a legacy from earlier land-use:due to ceased or reduced grazing pressure,forests are invading grasslands until the potential forest cover allowed by climate and soil is reached.The number of forest patches significantly increased at one site(Fülöpháza),while it decreased at two sites(Bugac and Orgovány)and showed no significant change at the fourth site(Tázlár).This indicates that forest encroachment can happen at least in two different ways:through the emergence of new forest patches in the grassland,and through the extension and coalescence of already existing forest patches.Though the present work revealed increasing tree cover at a decadal time scale,the dynamic process should be monitored in the future to see how the vegetation reacts to further aridification.This could help devise a conservation strategy,as the woody/non-woody balance has a profound influence on basic ecosystem properties.展开更多
文摘Net primary productivity and species diversity of herbaceous vegetation of banj-oak （Quercus leucotrichophora A. Camus） forest in Kumaun Himalaya, India were analyzed. Across different growth forms （tall forbs, short forbs, cushion and spreading forbs, grasses）, short forbs were most dominant component during rainy season （1VI=152） and winter season （IVI=167） and grasses during the winter season （IVI=148）. Maximum above-ground production occurred during rainy season （132.5 g m-2） and minimum during winter season （2.8 g m-~）. Below-ground production was maximum （85.9 g m-x） during winter season and minimum （14.9 g m-x） during summer season. Annual net shoot production was 15o g m-~ and below-ground production was 138 g m-~. Of the total input 61% was channeled to above- ground parts and 39% to below-ground parts.
文摘The experiment was conducted during the short dry and the short rainy seasons in 2008. A botanical inventory and relative frequencies of forage selected by Djallonke sheep grazing were developed by observation and hand-plucking. Chemical composition and in vitro organic matter digestibility （IVOMD） of hand-plucked material was determined. From July to October, woody plants are a major component of the sheep diet. Sheep selected 40 woody plants and 21 species of herbaceous. During the dry season, grazing occurred more frequently in the fallows. The most frequent woody species belonged to Elaeis guineensis and Fagara zanthoxyloides. At the rainy season, a high proportion of Panicum maximum and Eleucine indica were sampled. Crude protein was high in woody leaves at the dry season. Crude fibre were more variable in herbaceous than in woody and herbaceous were generally higher in the levels of fibre. Chromolaena odorata, Citrus sinensis, Vitex doniana were very high in IVOMD. Spondias mombin, Moringa oleifera, Persea americana, Psidium guajava, Dialium guineense presented lowest values in IVOMD. Among herbaceous, Andropogon gayanus and Panicum maximum still presented a high value of IVOMD at the dry season. High proteins suggest woody with potential as nitrogen supplements to ruminants fed low quality forage during the dry season.
基金supported by the National Research,Development and Innovation Office,Hungary[grant number FK 134384 to L.E.,KKP 144068 and K 137573 to P.T.,and FK 142428 to Z.B.]the János Bolyai Research Scholarship of the Hungarian Academy of Sciences(to L.E.and Z.B.)the Stipendium Hungaricum Scholarship(to K.V.H.and I.P.)。
文摘In the Eurasian forest-steppe,with increasing aridity,the balance between naturally co-existing forest and grassland patches is expected to shift towards grassland dominance in the long run,although feedback mechanisms and changes in land-use may alter this process.In this study,we compared old and recent aerial photographs of Hungarian forest-steppes to find out whether and how the forest proportion and the number of forest patches change at the decadal time scale.The percentage area covered by forest significantly increased in all study sites.The observed forest encroachment may be a legacy from earlier land-use:due to ceased or reduced grazing pressure,forests are invading grasslands until the potential forest cover allowed by climate and soil is reached.The number of forest patches significantly increased at one site(Fülöpháza),while it decreased at two sites(Bugac and Orgovány)and showed no significant change at the fourth site(Tázlár).This indicates that forest encroachment can happen at least in two different ways:through the emergence of new forest patches in the grassland,and through the extension and coalescence of already existing forest patches.Though the present work revealed increasing tree cover at a decadal time scale,the dynamic process should be monitored in the future to see how the vegetation reacts to further aridification.This could help devise a conservation strategy,as the woody/non-woody balance has a profound influence on basic ecosystem properties.
