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1.
《Palaeoworld》2014,23(3-4):336-356
Lauraceae is among the largest and floristically most important woody plant families in subtropical and tropical zones. However, the Cenozoic fossil records of Lauraceae are mostly from mid-latitude regions. Here we described eight lauraceous species from the Oligocene of Ningming, Guangxi, South China on the basis of leaf compressions with cuticular structure, providing new evidence for high diversity of Lauraceae in the low latitude region of the northern hemisphere during the late Paleogene. The extant genera to which the Ningming Oligocene fossils are possibly closely related include Cinnamomum, Neolitsea, Litsea, Alseodaphne, Laurus, and Beilschmiedia. All of these extant genera except Laurus still exist in Guangxi today, whereas Laurus is currently distributed in the Mediterranean and adjacent regions. A cladistic analysis based on leaf architectural and leaf cuticular characters for Paleogene Lauraceae species in the world indicated a possible relationship between European and East Asian Paleogene species.  相似文献   

2.
As humans continue to explore the last uncharted regions of the planet, discoveries of previously unknown species of large vertebrates have become infrequent. Here, we report on the discovery of a spectacular new species of giant, secretive, frugivorous, forest monitor lizard (Genus: Varanus) from the forests of the northern Philippines. Using data from morphology and mitochondrial and nuclear DNA sequences, we demonstrate the taxonomic distinctiveness of this new 2 m long species and provide insight into its historical biogeography and systematic affinities. Our molecular phylogenetic analyses indicate that the new species is closely related to Varanus olivaceus (from southern Luzon and nearby islands), but it differs from this and other varanids with respect to characteristics of scalation, colour pattern, body size, anatomy of the reproductive organs and genetic divergence. The new species appears to be restricted to forests of the central and northern Sierra Madre mountain range; it is separated from the range of V. olivaceus by a more than 150 km stretch that includes at least three low-elevation river valley barriers to dispersal. This discovery identifies a seldom-perceived biogeographic boundary and emphasizes the need for continued biodiversity research in the megadiverse conservation hotspot of the Philippines. It is anticipated that the new species will serve as an important flagship species for conservation efforts aimed at preserving the remaining forests of northern Luzon.  相似文献   

3.
A new species of Lauraceae, Beilschmiedia vestita, from the Brazilian Atlantic forest, in Minas Gerais state, is described and illustrated. Its morphological similarities and differences in relation to other species of Beilschmiedia are discussed. Distribution, habitat, phenology, etymology, and the IUCN Red List category are also provided.  相似文献   

4.
Heavy natural disturbance in large protected areas of former commercial forests increasingly evokes European parliaments to call for management intervention because a loss of habitats and species is feared. In contrast, natural early successional habitats have recently been recognised as important for conservation. Current knowledge in this field mostly results from studies dealing only with selected taxa. Here we analyse the success of species across 24 lineages of three kingdoms in the Bavarian Forest National Park (Germany) after 15 years of a European spruce bark beetle (Ips typographus L.) outbreak that led to rapid canopy opening. Using indicator species analysis, we found 257 species with a significant preference for open forests and 149 species with a preference for closed forests, but only 82 species with a preference for the stand conditions transitional between open and closed forests. The large number of species with a preference for open forests across lineages supports the role of this bark beetle as a keystone species for a broad array of species. The slowdown of the outbreak after 15 years in the core zone of the national park resulted in less than half of the area being affected, due to variability in stand ages and tree species mixtures. Our case study is representative of the tree species composition and size of many large protected montane areas in Central European countries and illustrates that (1) natural disturbances increase biodiversity in formerly managed forests and (2) a montane protected area spanning 10,000 ha of low range mountains is likely sufficient to allow natural disturbances without a biased loss of closed-forest species.  相似文献   

5.
Sequence data from a broad geographical region and different habitats show that the Inocybe praetervisa clade is comprised of four closely related species. These species of section Marginatae are characterized by having nodulose spores and a stipe that is abundantly pruinose only in the upper half. Inocybe praetervisa occurs in Southern Europe in mountainous mixed coniferous forests, and is not confirmed from Northern Europe. Inocybe rivularis occurs in northern boreal forests up to the lower alpine zone, associated with Betula in moist habitats, and is not confirmed from Southern Europe. Inocybe taxocystis is confirmed as a later synonym of I. favrei. The species has a wide geographical distribution range in Europe, mainly restricted to the alpine zone and moist soils, associated with Salix herbacea. Inocybe arctica is here described as a new species. It occurs in the arctic and higher alpine zones, associated with Dryas octopetala, Salix polaris, S. reticulata and S. herbacea. All species except I. arctica are shown to have an intercontinental distribution range and are confirmed from North America. Sequence data suggest the occurrence of one additional species in the alpine zone of China. A key to the species in the I. praetervisa group is provided.  相似文献   

6.
Rampant deforestation has caused the loss and fragmentation of natural habitats, which has precipitated a global biodiversity crisis. Research on how land-use change contributes to a loss of biodiversity is urgently needed, especially in ecosystems that have undergone rapid anthropogenic changes. We sought to investigate the extent to which habitat loss, fragmentation, and habitat split (the separation of forest and aquatic habitats) negatively influenced taxonomic diversity, functional diversity, total abundance, and the individual abundances of five anuran species in the Brazilian Cerrado. We sampled anurans between December 2017 and March 2018 using pitfall traps at sites distributed along a gradient of habitat fragmentation/habitat split: unfragmented forest, forest fragments without habitat split, and forest fragments with habitat split. Forest cover was measured within a 1-km radius of each site. Sites within unfragmented forests had higher taxonomic and functional diversities than either fragment type. Taxonomic diversity was highly correlated with functional diversity, but we did not find a pattern to the loss of functional traits. Total anuran abundance and the abundances of Chiasmocleis albopunctata, Physalaemus cuvieri, and Rhinella diptycha were higher in unfragmented forests compared to forest fragments. No species was more abundant in fragments than in unfragmented forests. Our results indicate that the fragmentation of forests by agricultural land use is directly and indirectly responsible for the loss of taxonomic and functional diversity, as well as for reducing population sizes of ground-dwelling anurans. Although we did not find a distinct effect of habitat split on ground-dwelling anurans, our study underscores the importance of preserving continuous forest habitats for the maintenance of anuran diversity in the Cerrado.  相似文献   

7.
《Palaeoworld》2016,25(1):104-115
Roses (Rosa, Rosaceae) are arguably the most admired ornamental plants in the world. Southwestern China is the center of diversity for many extant native species of Rosa and fossils found in this region are critical for understanding the evolution of this genus. Herein, we report a leaf fossil record with good preservation from the late Miocene of Yunnan Province. The opposite and odd-pinnate leaf is composed of seven elliptical leaflets, with close, crenulate, and regular marginal teeth. The stipules are lanceolate and adnate to the petiole. Additionally, the secondary veins are semicraspedodromous, showing the same venation pattern as most living Rosa species in southwestern China. On the basis of the extensive morphological comparisons, we propose a new species, R. fortuita T. Su et Z.K. Zhou n. sp. This is the first confirmed Rosa leaf fossil record in China, and the discovery of R. fortuita n. sp. indicates that Rosa existed in southwestern China by the late Miocene. It suggests that Rosa was distributed in subtropical or temperate forests and shared a similar ecological niche as Rosa in Europe during the Oligocene and Miocene. The modern diversification of Rosa in southwestern China is thought to have been closely associated with the continuous uplift of the Qinghai-Tibet Plateau since the late Miocene, creating complex topography and a variety of climate conditions.  相似文献   

8.
Ectomycorrhizal (ECM) fungi historically were considered poorly represented in Neotropical forests but in the central Guiana Shield substantial areas are dominated by leguminous ECM trees. In the Upper Potaro Basin of Western Guyana, ECM fungi were sampled for 7?years during the rainy seasons of 2000–2008 in three 1-ha plots in primary monodominant forests of the ECM canopy tree Dicymbe corymbosa (Fabaceae subfam. Caesalpinioideae). Over the plot sampling period sporocarps of 126 species of putative or confirmed ECM fungi were recovered. These taxa represented 13 families and 25 genera of primarily Agaricomycetes, but also Ascomycota (Elaphomycetaceae), the majority of which are new to science. Russulaceae contained the most species (20 Russula; 9 Lactarius), followed by Boletaceae (8 genera, 25 spp.), Clavulinaceae (17 Clavulina), and Amanitaceae (16 Amanita). An additional 46 species of ECM fungi were collected in forests of the Upper Potaro Basin outside the study plots between 2000 and 2010, bringing the regional number of ECM species known from sporocarps to 172. This is the first long-term ECM macrofungal dataset from an ECM-dominated Neotropical forest, and sporocarp diversity is comparable to that recorded for ECM-diverse temperate and boreal forests. While a species accumulation curve indicated that ECM sporocarp diversity was not fully recovered inside of the plots,?~80% of the total species were recovered in the first year. Sequence data from ECM roots have confirmed the ECM status of 56 taxa represented by corresponding sporocarp data. However,?>50% of ECM fungal species from roots remain undiscovered as sporocarps, leading to a conservative estimate of?>?250 ECM species at the Potaro site. Dicymbe forests in Guyana are a hotspot for ECM fungal diversity in the Neotropics.  相似文献   

9.
Floodplain forests are characterized by high and increasing levels of invasions by plant species, but the factors that drive their spread are insufficiently understood. Using data from 708 plots surveyed twice (1998, 2008) supplemented with further data (management, stand age, distance to dispersal corridors, type of ecosystems invaded) we analyzed the factors which shape the local distribution, growth, persistence and spread of three invasive alien tree species (Acer negundo, Ailanthus altissima, Robinia pseudoacacia) in the National Park Donau-Auen in Austria. Using Generalized Linear Models (GLMs), we found that the distribution of the study species per plot is contingent on stand age (R. pseudoacacia), type of floodplain forest (A. negundo, A. altissima) and distance to the next water body (A. negundo). For all study species, colonization of new plots between both surveys is driven by short distance spread from already established invasion foci. Moreover, recipient habitats (softwood vs. hardwood floodplain forests) modify invasion success in species-specific ways. The probability of occurrence and colonization of plots located in softwood floodplain forests is higher for A. negundo, whereas A. altissima more frequently colonizes hardwood floodplain forests. Persistence of R. pseudoacacia decreases with stand age, whereas its growth rate is significantly higher in plots located in zones where management is allowed than in those which are not managed. Persistence and growth of the other two study species were not related to any explanatory variables analyzed. The on-going spread of the study species in the National Park Donau-Auen suggests that their local distribution is in disequilibrium, i.e. not all suitable habitat patches have yet been colonized. This implies that increased management efforts are necessary to reverse the spread of alien tree species in the study area and to maintain the high conservation value of this iconic area which protects one of the largest floodplain forests in Europe.  相似文献   

10.
Jens G. Rohwer 《Grana》2018,57(3):178-213
In this study, pollen grains of 74 taxa (84 specimens) of the Cryptocarya group, including 22 type collections, have been examined by scanning electron microscopy. Pollen grains of Aspidostemon, Endiandra, Hexapora, Potameia and Triadodaphne are described here for the first time. For the other genera (Beilschmiedia, Cryptocarya, Eusideroxylon, Potoxylon) the results of previous studies are largely confirmed, but a novel type of exine covered by clavate-baculate structures was found in a few Cryptocarya species (C. gracilis and C. macrodesme from New Caledonia, C. saligna from South America). A larger diversity of spinule morphology and density than hitherto known is documented among the African species of Beilschmiedia.  相似文献   

11.
The potential impact of new invasive tree pests and diseases is usually quantified in economic terms. The ecological and social impacts are less often assessed. Using a comprehensive literature review we assess the potential ecological and social impact of two non-native invasive species (the box tree moth, Cydalima perspectalis and the fungus Calonectria pseudonaviculata) that threaten the survival of box tree, Buxus spp. in forests in Europe and the Caucasus. A total of 132 fungi, 12 chromista (algae), 98 invertebrate and 44 lichens were found to use Buxus spp. Of these, 43 fungi, 3 chromista and 18 invertebrate species have only been recorded on Buxus spp., suggesting that these species are obligate on Buxus spp. and are most at risk from in the loss of Buxus spp. due to these invasive pest and disease species. Buxus spp. was shown to be important for soil stability and water quality but there was no information on other ecosystem functions provided by Buxus spp. Buxus was found to be of considerable historical cultural importance but there was very limited information on current social values and uses. Buxus trees, wood and leaves are associated with different folklore and sacred rites which are still particularly important in the Caucasus. While we could not find any assessment of the economic value of Buxus forests the biodiversity, cultural and social values of Buxus identified here indicate that its loss could have major indirect and non-market economic effects. This work highlights the importance of studying the ecological and societal implications of biological invasions.  相似文献   

12.
Understory vegetation plays a crucial role in carbon and nutrient cycling in forest ecosystems; however, it is not clear how understory species affect tree litter decomposition and nutrient dynamics. In this study, we examined the impacts of understory litter on the decomposition and nutrient release of tree litter both in a pine (Pinus sylvestris var. mongolica) and a poplar (Populus × xiaozhuanica) plantation in Northeast China. Leaf litter of tree species, and senesced aboveground materials from two dominant understory species, Artemisia scoparia and Setaria viridis in the pine stand and Elymus villifer and A. sieversiana in the poplar stand, were collected. Mass loss and N and P fluxes of single-species litter and three-species mixtures in each of the two forests were quantified. Data from single-species litterbags were used to generate predicted mass loss and N and P fluxes for the mixed-species litterbags. In the mixture from the pine stand, the observed mass loss and N release did not differ from the predicted value, whereas the observed P release was greater than the predicted value. However, the presence of understory litter decelerated the mass loss and did not affect N and P releases from the pine litter. In the poplar stand, litter mixture presented a positive non-additive effect on litter mass loss and P release, but an addition effect on N release. The presence of understory species accelerated only N release of poplar litter. Moreover, the responses of mass loss and N and P releases of understory litter in the mixtures varied with species in both pine and poplar plantations. Our results suggest that the effects of understory species on tree litter decomposition vary with tree species, and also highlight the importance of understory species in litter decomposition and nutrient cycles in forest ecosystems.  相似文献   

13.
郑维艳  曾文豪  唐一思  石慰  曹坤芳 《生态学报》2018,38(24):8676-8687
以中国大陆北热带及亚热带地区优势科樟科、壳斗科植物为研究对象,利用专著发表大量的样方数据和物种分布数据,分析樟科、壳斗科与群落构建的关系、它们各大属的地理分布格局,探讨影响其分布的可能历史原因。结果表明:中国大陆北热带及亚热带地区森林乔木层优势科为樟科、壳斗科、山茶科、杜鹃花科。樟科、壳斗科物种丰富度均与其所在群落的物种丰富度呈现一定的正相关,樟科对群落构建的贡献较大。樟科、壳斗科植物种的空间多样性分布中心均出现在我国亚热带中部偏南地区。樟科的厚壳桂属、琼楠属以及壳斗科的锥属物种多样性分布中心主要在南亚热带及北热带区域,以广西、云南省份的南部为主。樟科的樟属、新木姜子属、润楠属、木姜子属及壳斗科的柯属、青冈属主要分布在我国大陆北热带及亚热带中部偏南的地区,其多样性分布中心与樟科、壳斗科科水平的物种多样性分布中心极为相似。樟科的山胡椒属、楠属、黄肉楠属,壳斗科的栎属主要分布在研究区域中部以西的地区。研究结果佐证物种的生态学特性以及生物地理学历史综合作用导致目前樟科和壳斗科植物的生物多样性分布格局。  相似文献   

14.
Floral characters are important for the systematics of the Lauraceae. However, structure and development of the flowers remain poorly known in the family. In this study, we observed the variation and early development of flowers of Beilschmiedia appendiculata, which belongs to the Cryptocarya clade of the family. The results indicate that the shoot apical meristems (SAMs) of the floral buds are enlarged and become a platform for the programmed initiation of the floral organs; floral organs develop basically in an acropetal pattern; phyllotaxis is whorled, initiation of floral primordia within a whorl is asynchronous; floral merosity is extremely variable, for example, dimerous, trimerous, tetramerous, dimerous plus trimerous, and trimerous plus tetramerous. In addition, this species has lost the innermost staminal whorl and glands are not closely associated with stamens of the third staminal whorl, which is unusual in the family Lauraceae. Our new observations broaden our knowledge of the variation of floral structure in Beilschmiedia and pose a fundamental question regarding the ecology underlying the lability of floral organs in B. appendiculata.  相似文献   

15.
16.
Parablastocatena tetracerae gen. et sp. nov. and Corynesporella licualae sp. nov., collected on dead branches of Tetracera asiatica and Licuala fordiana, respectively, in tropical forests of China, are described and illustrated. Parablastocatena tetracerae is the type species for a new monotypic genus in possessing macronematous conidiophores forming distinct synnemata with holoblastic conidiogenesis and euseptate, short-chained conidia ending in a paler brown rostrum, whereas C. licualae is distinguished from described species by the smaller conidia with long appendages. A key to currently accepted species of Corynesporella is provided.  相似文献   

17.
Invasive species are widely recognized as altering species and community dynamics, but their impacts on biogeochemical cycling and ecosystem processes are less understood. The emerald ash borer (Agrilus planipennis Fairmaire) is a phloem feeding beetle that was inadvertently introduced to the US in the 1990s and relies solely on ash trees (Fraxinus spp.) to complete its life cycle. Ash trees have a wide geographic distribution and are an important component of many different forest types in the US. The larval feeding behavior of the emerald ash borer (EAB) effectively girdles the tree’s phloem tissue resulting in tree mortality in as little as 2 years and stand mortality in as little as 5 years. Using the forest inventory and analysis database, we found that forest lands in the lower 48 states hold approximately 8.7 billion ash trees and saplings, which represent ~2.5 % of the aboveground forest carbon mass. Furthermore, we measured tree growth in 7 EAB impacted and 5 non-EAB impacted temperate forests in the Midwestern United States to quantify the impacts of EAB induced tree mortality on tree growth. We hypothesized that the initial C lost would be partly compensated for by the enhanced non-ash tree growth in EAB-impacted regions relative to non-EAB impacted regions. The EAB disturbance enhanced growth of non-ash trees in the EAB impacted region relative to the non-EAB impacted region. Results also indicate that in EAB impacted areas, growth of trees from the genera Acer and Ulmus responded most positively. Finally, we quantified annual biometric net primary productivity of the EAB impacted forests and compared these quantities to modeled growth of these forests in the absence of EAB and found that large scale ash tree mortality has reduced short term regional forest productivity. The loss of ash biometric net primary productivity is, in part compensated by enhanced growth of non-ash species. As expected, EAB disturbance severity was greater in forests with higher basal areas of ash. This study illustrates the ecosystem and regional scale impacts of invasive pest-induced disturbance on biogeochemical cycling and forest species composition.  相似文献   

18.
The widespread cyanolichen genus Peltigera comprises many insufficiently known poorly delimited and/or undescribed species. Phylogenetic analysis of 252 Peltigera specimens from a wide range of habitat types in Estonia revealed 31 putative taxa (OTUs). Multivariate analysis revealed habitat-specific segregation between the Peltigera species along a gradient from humid eutrophic forests to dry oligotrophic forests and grasslands and along a soil pH gradient from alkaline soils of alvar grasslands to acidic soils of conifer forests. The diversity of Peltigera was the highest on roadsides and dunes and the lowest in alvar habitats which, however, supported the unique assemblage of undescribed Peltigera taxa. Deciduous broad-leaved forests, too, included several undescribed or rare and red-listed species. The results demonstrate that in Estonia many Peltigera species have narrow habitat requirements and are at present threatened by habitat loss and degradation.  相似文献   

19.
Floodplain forests in rapidly changing landscapes with increased urbanization may reshape habitat conditions to the detriment of native biota and favor invasive species. We assessed whether introduced Ligustrum sinense distribution and abundance are causally linked to urbanization and whether mechanisms that promote L. sinense cause the demise of native plant species. We surveyed vegetation in 12 independent floodplain forests along an urban to rural gradient in South Carolina, USA. We then used a seedling transplant experiment in nine watersheds to assess how increased urban development affects survival and growth of L. sinense and three native species over two growing seasons. Urban development ranged from 1 to 45% and L. sinense cover was positively associated with development. However, in our transplant experiment, growth and survival of L. sinense did not differ significantly among watersheds. Native species were able to survive at all sites, but performance varied greatly among sites and species but not as a function of urban development. Our results suggest that although L. sinense invasion and urbanization are related (likely due to proximity of propagules from urban sources), the demise of native species cannot be explained by increased urbanization or changes in edaphic conditions and points to L. sinense as an agent of change in our floodplain forests. These results indicate that all floodplain forests are at risk of invasion if propagules arrive and that land managers need to be vigilant against new species introductions regardless of the proximity to urban areas.  相似文献   

20.
Ligustrum lucidum is the major exotic tree in NW Argentina montane forests (Yungas). To assess the effects of its expanding invasion on avian communities we (1) measured different habitat properties (vertical forest structure and composition, vegetation cover, light availability, air temperature, air relative humidity and soil litter depth), (2) compared bird species composition and diversity in Ligustrum-dominated and native-dominated secondary forests and (3) analyzed seasonal patterns and changes in these variables between forest types. The study was conducted during 2010–2011 wet and dry seasons, at two altitudinal zones: 500–800 and 1100–1450 masl. Compared with native forests, Ligustrum dominated forests had a more homogeneous vertical forest structure and denser canopy cover (resulting in lower understory solar radiation), significantly lower understory cover and lower litter depth. Air temperature and relative humidity did not differ between forests in either season. Solar radiation was higher in the dry season in both forest types, but litter depth showed opposite patterns between seasons depending on forest type. We recorded 59 bird species in 21 families. Bird species abundance, richness and diversity indexes were significantly lower in Ligustrum-dominated relative to native forests of similar successional age, which had almost twice as many species as the former. Avian communities differed between altitudinal zones, but the difference was stronger between Ligustrum and native-dominated forests. Avian community composition was less variable in time and space in native forests than in Ligustrum-dominated ones. Our results suggest that L. lucidum invasion generates structurally homogeneous and simpler forests that represent a less suitable habitat for a diverse avifauna. This illustrates the wide ecological changes (from habitat properties and ecosystem functioning to vertebrate community composition) that the subtropical mountain forests of Argentina are experiencing with this invasion.  相似文献   

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