WOOD OF GINKGO IN THE TERTIARY OF WESTERN NORTH AMERICA

Scott , R. A., E. S. Barghoorn , and U. Prakash . (U.S. Geol. Sur., Denver, Colo.) Wood of Ginkgo in the Tertiary of western North America . Amer. Jour. Bot. 49(10): 1095–1101. Illus. 1962. —Woods of Ginkgo and extinct related genera are very rare in the fossil record in contrast to the numerous ginkgoalean leaves. Ginkgo wood may be distinguished from other gymnosperms by a combination of anatomical features herein described. Ginkgo wood from beds of Miocene age at Vantage, Washington, first identified by Beck, is assigned to a new species, G. beckii. Ginkgo wood from the upper Eocene Clarno Formation, John Day Basin, Oregon, is described as G. bonesii sp. nov. Scarcity of fossil ginkgoalean woods may reflect unusual susceptibility to degradation of their cell walls in contrast to the greater chemical resistance to degradation which features many coniferous woods.     

FOSSIL WOOD OF ROBINIA AND GLEDITSIA FROM THE TERTIARY OF MONTANA

Prakash , U., E. S. Barghoorn , and R. A. Scott . (Harvard U., Cambridge, Mass.) Fossil wood of Robinia and Gleditsia from the Tertiary of Montana . Amer. Jour. Bot. 49(7): 692–696. Illus. 1962.—Fossil woods representing 2 genera of the Leguminosae, Robinia Linnaeus and Gleditsia Clayton, have been identified from Tertiary beds in southern Montana. These woods are noteworthy owing to their exceptionally fine structural preservation and from the standpoint of their paleogeographical distribution. Neither genus now lives in the region of Montana.     

Ecosystem legacy of the introduced N2-fixing tree Robinia pseudoacacia in a coastal forest

Habitat invasibility has been found to increase dramatically following the alteration of ecosystem properties by a nonnative species. Robinia pseudoacacia, black locust, is a nitrogen-fixing, clonal tree species that aggressively invades open habitats and expands outside of plantations worldwide. Robinia pseudoacacia stands in Cape Cod National Seashore were particularly susceptible to a hurricane in 1991 that caused widespread blowdown and a dramatic reduction in Robinia in some stands. We used this change to investigate the lasting ecological effects of this nonnative species on this upland coastal ecosystem. We established replicate clusters of 20 × 20 m field plots within 50 m of each other that contained native pitch pine (Pinus rigida) and oak (Quercus velutina, Q. alba) forest, living Robinia stands, and stands in which Robinia was eliminated or reduced to less than 5 % cover by the hurricane. Net nitrification and extractable soil nitrate concentration differed significantly between stand types, in the order Robinia > former Robinia > pine-oak. Nonnative species cover differed significantly between each stand type, in the order Robinia > former Robinia > pine-oak. Invasion of Robinia pseudoacacia increased soil net nitrification and nitrogen availability and precipitated a change in forest species composition that favored nonnative species. The presence of elevated soil nitrogen and nonnative species persisted at least 14 years after the removal of the original invading tree species, suggesting that the invasion of a tree species left a legacy of altered soil biogeochemistry, a higher number of nonnative species, and greater nonnative species cover.     

MULTIVARIATE COMPARISON OF FOSSIL AND RECENT GINKGO WOOD

Multivariate statistical analysis of the anatomical structure of the wood of Recent Ginkgo biloba L. and of fossil Ginkgo beckii Scott, Barghoorn, & Prakash revealed significant differences not apparent through general microscopic observation. On the basis of a multiple discriminant analysis by computer of 10 anatomical characters, the living and fossil Ginkgo woods were separated into two distinct groups. All Recent wood specimens were classified into a single disjoint group by the computer, and all fossil wood specimens were classified into another without misclassifications when all 10 characteristics were included in the analysis. Three characters—number of pits per millimeter of tracheid length on radial wall, ray height, and tangential diameter of late wood tracheids—accounted for most of the discrimination between the two groups.     

Gleditisioxylon riojana nov. sp. en el Neógeno de Argentina: sus relaciones paleoambientales y biogeográficas

A new fossil species of Leguminosae is described from Neogene of northwest of Argentina. The good preservation of tissues and the diagnostic characters present in this fossil wood let assigning it to a new species of Gleditisioxylon Müller-Stoll and Madel. Gleditisioxylon riojana nov. sp. (Caesalpinoideae) has diagnostic features such as: growth rings distinct, semi-annular porosity, vestured pits, helical thickenings, simple plates, paratracheal parenchyma and rays 1-6 seriate. The possible climatic conditions of Toro Negro Formation were inferred by the use of xylological characters presents in this fossil wood. The presence of Gleditsioxylon added to other data, suggest a new hypothesis to explain the disjunction of Gleditsia L. genus and the occurrence of a single extant species in tropical and subtropical South America.     

Arthropod diversity of exotic vs. native Robinia species in northern Arizona

1 Arthropods were collected on native locust, Robinia neomexicana A. Gray, and exotic Robinia pseudoacacia L. in northern Arizona over a 2‐year period to determine the number of arthropod species and number of individuals present. 2 More arthropod species were found on the native (251) than on the exotic Robinia (174). 3 Greater species diversity was likewise found on the native than the exotic. The five most numerous insects collected each year accounted for 81% to 91% of the total number collected on the exotic and native Robinia in 1997 and 1998. Only 12 species occurred on both the native and exotic Robinia in both years. 4 These findings are discussed in the context of using exotic trees in plantations and ecological theory regarding rates of arthropod species accumulation on exotic hosts.     

A review of the genus Paraphyllanthoxylon

Thirteen species of petrified wood have been assigned previously to the genus Paraphyllanthoxylon which was established by Bailey (1924) as representative of the section Phyllanthoideae of the family Euphorbiaceae. Mädel (1962) considered the genus Paraphyllanthoxylon representative of only the Glochidion wood group of the section Phyllanthoideae. This necessitates the establishment of a new genus, Phyllanthoideoxylon, for fossil woods which have characteristics in common with several of the other wood groups in the section Phyllanthoideae. The thirteen previously identified species of Paraphyllanthoxylon are reviewed and compared with the characteristics of the genus. Eleven of these species are retained in Paraphyllanthoxylon Bailey (emend. Mädel), one (P. bangalamodense) is assigned to Phyllanthoideoxylon nov. gen. and one (P. keriense) is transferred to Bridelioxylon Ramanujam.     

Some fossil woods from the Palaeogene of Northern Kyushu,II

Four new species of petrified dicotyledonous woods obtained from the Oligocene of Tsuyazaki, fukuoka Prefecture have been described in a continuation of work from the previous paper;Acer palmatoxylum (Aceraceae),Cornus tsuyazakiensis (Cornaceae),Fraxinus oligocenica (Oleaceae) andHovenia palaeodulcis (Rhamnaceae). The fossil woods of those families are new records from the Palaeogene of Japan.     

Human impact on the forest vegetation in the western part of the Pannonic Plain (Yugoslavia)

A comparative phytosociological study was made out on two types of forest on the southern slopes of Moslavaka gora in the western part of the Pannonic Plain, Yugoslavia: acidophilic oak forest of Festuco-Quercetum petraeae Hruka 1975 and areas where Robinia pseudoacacia has been introduced by man. After cutting, the oakforest reestablishes spontaneously. Reafforestation with Robinia leads to changes irreversible in species composition and vegetational structure and prevents reestablishment of oak forest. The introduction of this allochthonous species prevents the primary wood from being restored. Forestry planting projects with a view to reducing the Robinia have so far proved ineffective.     

Facilitations between the Introduced Nitrogen-fixing Tree, Robinia pseudoacacia, and Nonnative Plant Species in the Glacial Outwash Upland Ecosystem of Cape Cod, MA

Robinia pseudoacacia, a nitrogen-fixing, clonal tree species native to the central Appalachian and Ozark Mountains, is considered to be one of the top 100 worldwide woody plant invaders. We initiated this project to determine the impact of black locust (Robinia pseudoacacia) on an upland coastal ecosystem and to estimate the spread of this species within Cape Cod National Seashore (CCNS). We censused 20 × 20 m plots for vegetation cover and environmental characteristics in the center of twenty randomly-selected Robinia pseudoacacia stands. Additionally, paired plots were surveyed under native overstory stands, comprised largely of pitch pine (Pinus rigida) and mixed pitch pine–oak (Quercus velutina and Quercus alba) communities. These native stands were located 20 m from the edge of the sampled locust stand and had similar land use histories. To determine the historical distribution of black locust in CCNS, we digitized and georeferenced historical and current aerial photographs of randomly-selected stands. Ordination analyses revealed striking community-level differences between locust and pine–oak stands in their immediate vicinity. Understory nonnative species richness and abundance values were significantly higher under Robinia stands than under the paired native stands. Additionally, animal-dispersed plant species tended to occur in closer stands, suggesting their spread between locust stands. Robinia stand area significantly decreased from the 1970’s to 2002, prompting us to recommend no management action of black locust and a monitoring program and possible removal of associated animal-dispersed species. The introduction of a novel functional type (nitrogen-fixing tree) into this xeric, nutrient-poor, upland forested ecosystem resulted in ‘islands of invasion’ within this resistant system.     

Specific activation of human T lymphocytes by Robinia pseudoacacia seeds' lectin.

Human peripheral blood and tonsil lymphocytes were fractionated into T and B cells by centrifugation after rosetting with native sheep erythrocytes and tested with Robinia pseudoacacia lectin. The purity of B- and T-enriched populations was checked by E-rosette formation or heterologous antisera specific for B or T lymphocytes. The proliferative response of T cells to Robinia lectin from all the donors tested was not found to differ from that of unfractionated cells, whereas no response of highly purified B cells could be observed to the lectin even with different concentrations of the lectin and different culture periods. B cells, however, were found to bind as much ³H labeled Robinia lectin as unfractionated lymphocytes. In addition, treatment of cells by antihuman T-lymphocyte antigen (HTLA) serum and complement before addition of Robinia lectin completely abolished their response, whereas similar treatment by antihuman B lymphocyte and monocyte antigen (HBLMA) serum did not prevent the T cells from incorporating thymidine. The Robinia lectin, like the other phytomitogens, thus appears to be a specific T-cell activator.     

Robinia pseudoacacia L.: A Lesser Known Tree Species for Biomass Production

Experiments with fast-growing tree species for biomass production in Germany have been mainly focused on the growth performance of Populus and Salix spp. Among the lesser-known species for energy plantations is Robinia pseudoacacia L. Special features of this species are its drought tolerance and its ability to fix nitrogen. Given the large share of marginal arable land in NE-Germany and the predicted climate change, R. pseudoacacia is expected to grow in importance. In order to evaluate the growth performance of this species under extreme conditions, four experiments were established in the post-mining landscape of the Lusatian lignite-mining district (NE-Germany). Biomass production was estimated for 3- to 14-year-old shoots on 4- to 14-year-old roots. Results for the annual production of oven-dried biomass of R. pseudoacacia ranged between 3 and 10 t ha^?1, which was substantially greater than the biomass of poplar and willow clones established on the same site. Economic analysis results show that the rotation period, the duration of the plantation, and the harvesting costs are important parameters for the economic return and cash flow in short-rotation coppice cultivation. The results show that the cultivation of R. pseudoacacia is an economically competitive land-use strategy for the post-mining landscapes considered in our study.     

Recovery of grassland after clear-cutting of invasive Robinia pseudoacacia – Long-term study in Prague (Czech Republic)

Invasive species belong to the main threats to dry grassland biodiversity. That́s why nature conservation managers seek the best ways to remove them and to support the restoration process of original natural habitats. We studied the effect of clear-cutting of invasive black locust (Robinia pseudoacacia L.) on the recovery of former species rich dry grassland vegetation. Ten permanent plots where R. pseudoacacia was cut down were long-term monitored in nature reserves protecting dry grasslands. The representation of dry grassland plants has been increased four times and the representation of synanthropic plants has been decreased two times during 40 years of succession even though R. pseudoacacia still relatively successfully resisted eradication efforts. During the succession after R. pseudoacacia cutting down, the Ellenberg indicator values for nutrients have decreased significantly, but no decrease in the nitrate content of the soil was observed. The long-term monitoring revealed that the restoration of dry grasslands invaded by R. pseudoacacia is possible but very time consuming.     

Bois plio-pléistocènes du gisement de saropée plateau de khorat, est de la Thaïlande

Alluvial deposits from the Mue Nam Mum river at Saropée, Khorat Region, Thailand, yielded about 60 wood specimens, attributed to Araucarioxylon sp., Shoreoxylon thaïlandense n.sp., Careyoxylon pondicherriense Awasthi, Terminalioxylon coriaceum Prakash and Awasthi, Terminalioxylon burmense Mädel-Angeliewa and Müller-Stoll, Pahudioxylon sahnii Ghosh and Kazmi, Cynometroxylon schlagintweitii Müller-Stoll and Mädel, and Albizzinium eolebekkianum Prakash. This association, attributed to a Plio-Pleistocene age, evokes a mixed deciduous forest, probably not far from a river and ancient volcanoes. The presence of Araucariaceae in South-Eastern Asia at a relatively recent epoch is pointed out. A comparison with other fossil wood localities reveals close floristic resemblance with Burma, Western Bengal and Kachchh.

Résumé

Une nappe fluviatile de la rivière Mue Nam Mum, gisement de Saropée, région de Khorat, en Thaïlande, a livré une soixantaine de bois fossiles, déterminés comme: Araucarioxylon sp.,Shoreoxylon thaïlandense n.sp., Careyoxylon pondicherriense Awasthi, Terminalioxylon coriaceum Prakash et Awasthi, Terminalioxylon burmense Mädel-Angeliewa et Müller-Stoll, Pahudioxylon sahnii Ghosh et Kazmi, Cynometroxylon schlagintweitii Müller-Stoll et Mädel et Albizzinium eolebekkianum Prakash. Cette association, évoquant une forêt semi-dense, s'est vraisemblablement développée à proximité d'un cours d'eau et d'anciens volcans. Elle est attribuée au Pliocène ou au Quaternaire ancien. La question de la présence d'Araucariaceae dans le Sud-Est asiatique à une époque relativement récente est évoquée. Une comparaison avec d'autres gisements à bois fossiles révèle des ressemblances floristiques avec la Birmanie, le Bengale occidental et le Kachchh.     

Activities of some enzymes of lignin formation in reaction wood of Thuja orientalis,Metasequoia glyptostroboides and Robinia pseudoacacia

The activities of the following five enzymes which are involved in the formation of lignin have been compared in reaction wood and in opposite wood: phenylalanine ammonia lyase (EC 4.3.1.5), caffeate 3-O-methyltransferase (EC 2.1.1.-), p-hydroxycinnamate: CoA ligase (EC 6.2.1.12), cinnamyl alcohol dehydrogenase (EC 1.1.1.-) and peroxidase (EC 1.11.1.7). The activities of the four first-named enzymes in the compression wood of Thuja orientalis L. and Metasequoia glyptostroboides Hu et Cheng were 2.8±1.4-fold and 2.6±1.5-fold higher than those in opposite wood, respectively, whereas peroxidase had the same level of activity in either type of wood. On the other hand, no differences were observed in the activities of the five enzymes between tension and opposite woods of Robinia pseudoacacia L. These findings are well in accord with the chemical structure of lignin in the compression and tension woods of the three species studied: high content of lignin rich in condensed units in compression wood, and little difference in lignin between tension and opposite woods.Abbreviations CAD cinnamyl alcohol dehydrogenase (EC 1.1.1.-) - OMT caffeate O-methyltransferase (EC 2.1.1-) - PAL phenylalanine ammonia lyase (EC 4.3.1.5) - PCL p-hydroxycinnamate: CoA ligase (EC 6.2.1.12) - PO peroxidase (EC 1.11.1.7)     

Competition and soil fungi affect the physiological and growth traits of an alien and a native tree species

Competition plays an important role in the replacement of native species by alien plants. A greenhouse experiment was conducted to investigate whether the competition pattern of alien Robinia pseudoacacia L. and native Quercus acutissima Carr. is affected by soil sterilization. Physiological traits, such as gas-exchange parameters and chlorophyll (Chl) content, and growth traits, such as the biomass accumulation of the two species, were examined in natural soil or in soil sterilized with benomyl. The results show that native Q. acutissima inhibits the growth of R. pseudoacacia in natural soil. When the two plants coexisted and competed under sterilization treatment, R. pseudoacacia was less inhibited by Q. acutissima and the competition of R. pseudoacacia decreased the growth of Q. acutissima in terms of biomass, Chl a, Chl b, total Chl, and Chl a/b. These results suggest that soil sterilization benefits the growth of R. pseudoacacia and changes the competition pattern by the changed soil biota. Soil sterilization increased the biomass of root nodules, which ultimately benefits the growth of R. pseudoacacia and root nodule bacteria may be important in the dispersal and invasion process of nitrogen-fixing alien plants such as R. pseudoacacia.     

The influence of black locust (Robinia pseudoacacia) flower and leaf fall on soil phosphate

To investigate the influence of black locust (Robinia pseudoacacia) flower and leaf fall on soil phosphate, we monitored litterfall, litter decomposition, and soil membrane phosphate in a R. pseudoacacia forest on Mt. Ilzasan, Seoul, Korea. R. pseudoacacia flower litter was 30–50% of total litter production in May and the flowers decomposed rapidly. More than 11% of R. pseudoacacia leaf litter decomposed from February to May, while that of Quercus spp. decomposed very little. Fast decomposition of R. pseudoacacia flower and leaf litter significantly increased membrane phosphate in the soil. The rapid nutrient-cycling of R. pseudoacacia through flower litterfall and rapid decomposition benefits the plant itself in the growing season when nutrients demand is increasing. Rapid nutrient-cycling might be a strategy that helps R. pseudoacacia to persist in poor soil environments.     

Effects of a Major Tree Invader on Urban Woodland Arthropods

Biological invasions are a major threat to biodiversity; however, the degree of impact can vary depending on the ecosystem and taxa. Here, we test whether a top invader at a global scale, the tree Robinia pseudoacacia (black locust or false acacia), which is known to profoundly change site conditions, significantly affects urban animal diversity. As a first multi-taxon study of this kind, we analyzed the effects of Robinia dominance on 18 arthropod taxa by pairwise comparisons of woodlands in Berlin, Germany, that were dominated by R. pseudoacacia or the native pioneer tree Betula pendula. As a negative effect, abundances of five arthropod taxa decreased (Chilopoda, Formicidae, Diptera, Heteroptera, Hymenoptera); 13 others were not affected. Woodland type affected species composition of carabids and functional groups in spiders, but surprisingly did not decrease alpha and beta diversity of carabid and spider assemblages or the number of endangered species. Tree invasion thus did not induce biotic homogenization at the habitat scale. We detected no positive effects of alien dominance. Our results illustrate that invasions by a major tree invader can induce species turnover in ground-dwelling arthropods, but do not necessarily reduce arthropod species abundances or diversity and might thus contribute to the conservation of epigeal invertebrates in urban settings. Considering the context of invasion impacts thus helps to set priorities in managing biological invasions and can illustrate the potential of novel ecosystems to maintain urban biodiversity.     

New species of pinaceous fossil wood from the Pliocene of southern Primorye (Russian Far East)

New species of the Pinaceae, Abies chavchavadzeae and Piceoxylon ussuriense, are described on the basis of fossil woods from the Pliocene of the Pavlovka lignite field (southern Primorye). For the first time, fossil wood of Abies is reported from the Russian Far East.