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Plant communities and reproductive phenology in mountainous regions of northern Libya

Journal of Forestry Research 2017年第4期28卷 741-761页

作者： Ahmad K. Hegazy Hanan F. Kabiel Saud L. Al-Rowaily Lesley Lovett-Doust Abd El-Nasser S. Al Borki Department of Botany and Microbiology Faculty of ScienceCairo UniversityGiza 12613Egypt Department of Plant Production College of Food and Agricultural SciencesKing Saud UniversityRiyadhSaudi Arabia Department of Biology and Chemistry Nipissing UniversityNorth BayONCanada Department of Botany Faculty of Sciences and ArtsUniversity of BenghaziAgdabiaLibya

Within the semi-desert landscape of northern Libya, two sub-humid escarpments occur: Al-Akhdar in the east and Nafusa (Jabal Al-Gharbi) in the west. This study compares plant communities in the two regions, which are along an elevation gradient, in terms of species composition and diversity, frequency of different Raunkiaer life forms, and reproductive phenology. The two regions differed in species composition and life-form frequency between regions and between elevation zones within each region. Patterns were associated with the lower rainfall and lower moisture-holding capacity of soils at Nafusa, resulting in more xeric conditions. Only 13% of species were shared between the two regional landscapes. Species diversity, life-form frequency, and duration of the flowering-fruiting phenophase were all affected by elevation above sea level. The duration of flowering and fruiting in spring and fall was associated with environmental conditions, although there were different thresholds in the two regions. There was both a spring and fall episode of flowering at Nafusa, but only spring flowering at Al-Akhdar. It is anticipated that there will be a gradual shift of plant communities to higher elevations and loss of certain sensitive species in response to ongoing climate change.

关键词： Altitudinal gradient Raunkiaer life forms reproductive phenology Southern Mediterranean

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Patterns and drivers of plant sexual systems in the dry-hot valley region of southwestern China

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Plant Diversity 2024年第2期46卷 158-168页

作者： Rong Ma Qi Xu Yongqian Gao Deli Peng Hang Sun Bo Song State Key Laboratory of Plant Diversity and Specialty Crops/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China College of Life Sciences Shaanxi Normal UniversityXi'an 710119China Yunnan Forestry Technological College Kunming 650224China School of Life Science/Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment Yunnan Normal UniversityKunming 650500YunnanChina

Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and maintenance of plant biodiversity and predicting its responses to environmental change. In this study, we determined the patterns of plant sexual systems and their associations with geographic elements and various life-history traits in dry-hot valley region of southwestern China, an extremely vulnerable ecosystem. Of the 3166 angiosperm species recorded in this area, 74.5% were hermaphroditic,13.5% were monoecious and 12% were dioecious, showing a high incidence of diclinous species. Diclinous species were strongly associated with tropical elements, whereas hermaphroditic species were strongly associated with temperate and cosmopolitan elements. We also found that hermaphroditism was strongly associated with showy floral displays, specialist entomophily, dry fruits and herbaceous *** was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, fleshy fruits, and woody plants, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, dry fruits, and herbaceous plants. In addition, hermaphroditic species with generalist entomophily tended to flower in the dry season, whereas diclinous species with specialist entomophily tended to flower in the rainy season. However, independent of sexual systems, plants that produce dry fruits tended to flower in the rainy season and set fruits in the dry season, but the opposite pattern was found for fleshy fruit-producing plants. Our results suggest that in the dry-hot valleys, plant sexual systems are associated with geographic elements as well as various life-history traits that are sensitive to environmental change.

关键词： Floral traits Fruit type Growth form Pollination system reproductive phenology

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Flowering and seeding patterns in pure and mixed Nothofagus forests in Southern Patagonia

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Ecological Processes 2016年第1期5卷 261-272页

作者： Monica Toro Manriquez Luciana Mestre Maria Vanessa Lencinas Alvaro Promis Guillermo Martinez Pastur Rosina Soler National Scientific and Technical Research Council(CONICET) Austral Center for Scientific Research(CADIC-CONICET)Houssay 2009410 UshuaiaTierra del FuegoArgentina Department of Silviculture and Nature Conservation University of ChileAv.Santa Rosa 113159206 SantiagoLa PintanaChile

Introduction:Variation in reproductive phenology among species is an important mechanism for maintaining species *** mixed forests,the impact of limiting(biotic and abiotic)factors on tree reproductive success regulates the maintenance of species in balanced proportions or the conversion towards monospecific *** study offer a significant first approach to the reproductive phenology of mixed forests,assessing flowering,seeding and loss factors on reproductive success in three forest types(pure deciduous Nothofagus pumilio(Np),evergreen Nothofagus betuloides(Nb)and mixed(M)forests),comparing also between two geographical locations(coast and mountain),during one growing ***:Flowering falling started early in *** fall occurred first and more concentrated in Np,while in Nb,it was progressive during *** in M combined both patterns,but with better reproductive performance of both *** production was greater in Nb(42,900,000 ha^(−1))than in Np(710,000 ha^(−1)),while M presented intermediate values(31,900,000 ha^(−1)).Abortion was greatest in Np(19% of female flowers and 10% of immature fruits),while fruit predation was low(7-9%)in all forest *** seed was the main loss factor,but with low net values for each species in *** geographical location,sea proximity generated a quick starting of the growing season in coast compared to mountain ***,we detected forest types×location interactions in flowering and seeding patterns(*** male flower production and in empty and viable seeds),with differences in species response according to ***:Both deciduous and evergreen species have reproductive advantages in mixed compared to pure ***,mixed were more similar to pure evergreen forests in their reproductive traits and the incidence of the limiting *** study of only one growing season does not allow us to conclude whether mixed forests are stable communities,but we cont

关键词： Broadleaved Mixed forest Geographical location Leaf habit reproductive phenology Seed quality

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Species-specific phenological responses to long-term nitrogen fertilization in an alpine meadow

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Journal of Plant Ecology 2017年第2期10卷 301-309页

作者： Tan-Feng Yin Li-Li Zheng Guang-Min Cao Ming-Hua Song Fei-Hai Yu Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesA11Datun RoadChaoyang DistrictBeijing 100101China School of Nature Conservation Beijing Forestry University35 East Qinghua RoadHaidian DistrictBeijing 100083China University of Chinese Academy of Sciences No.19 Yuquan RoadBeijing 100039China Northwest Institute of Plateau Biology Chinese Academy of Sciences59 Xiguan DajieXining 810008China

Aims Long-term nitrogen(N)fertilization has profound impacts on com-munity structure and ecosystem function,but little is known about its effects on plant ***,no published study has examined effects of N chemical forms on plant *** in an alpine meadow on the Tibetan Plateau,we monitored reproductive phenology of six common plant species after 8 years of fertilization with different N chemical forms(addition of 7.5 g N m^(−2) yr^(−1) in the forms of ammonium,nitrate and ammonium nitrate),with no N addition as the *** Findings Eight years of N fertilization affected plant reproductive phenology,and such effects depended on the species,N form and phenological *** with ammonium generally delayed,advanced or did not change flowering and fruiting phases of the alpine ***,fertilization with ammonium affected the temporal dispersion of reproductive phenology among the six species,espe-cially among the late-flowering *** could reduce the overlap of flowering and fruiting and increase phenological *** with nitrate only delayed the senescence phase of Elymus nutans,and fertilization with ammonium nitrate did not affect reproductive phenology of the six alpine plants.N fertilization with any form increased the overlap in senescence among the six *** conclude that long-term N fertilization can cause shifts in plant phenology and such effects depend on N chemical *** results also suggest that phenological comple-mentarity could be a mechanism underlying resource partitioning and thus species coexistence in the face of changing N availability with different chemical forms.

关键词： reproductive phenology fertilization nitrogen forms temporal dispersion in phenology alpine meadow

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