Life Form Spectrum Research Articles

Collembolan communities of the Ubsu-Nur Basin and adjacent mountains (Russia, Tuva)

Collembolan communities were investigated in different mountain soils of tundra, forest and steppe belts on the southern macroslope of the Eastern Tannu-Ola Mountain Range as well as in some dry and psammophytic steppes in the arid Ubsu-Nur Basin of the Tuva Republic. The fauna of these areas is unique with many species new to science and some species shared with the Mongolian fauna. A total of 95 springtail species were recorded in the 16 sites studied. Of this number, 81 species inhabited sites along altitudinal gradients. Specifically, 38, 50 and 49 species were recorded in alpine tundra, mountain forests and mountain steppes, respectively. In plain steppes 34 species (23 in dry and 23 in psammophytic steppes) were noted. The highest density was found in high altitude pine-larch forest, in the zone of maximum annual precipitation. Along the altitudinal gradient, with increasing aridity from the alpine tundra to steppe sites, dominance structure, spectrum of life forms and spatial distribution of collembolan communities changed markedly. Furthermore, levels of diversity and density decreased while Lexis's aggregation index increased gradually with increasing aridity both in forest and steppe sites. In dry larch forests euedaphic forms were dominant. Collembolan communities of the dry and psammophytic plain steppes of Southern Tuva were characterised by the superdominance of one or two specific species. Decreasing collembolan diversity and density were observed with increasing distance from the latitudinally oriented Tannu-Ola Range, which trapped precipitation (dry plain steppe) and also with penetration into the depth of the sand massif (psammophytic steppe). In Tuva steppes, collembolan populations, especially xerophilous or psammophilous species (Folsomides aridoviato, Brachystomella parvula, Isotomodella psammophila and Xenylla spp.) were most numerous in the summer due to increased precipitation during this period. Patchy distribution of Collembola in steppes is associated with favourable microhabitats (i.e. rhizospheres of certain plants).

Vegetation analysis of the down-stream part of Wadi Gaza, Palestine

The analysis of the life form and chorotype spectra of the vegetation of the down-stream part of Wadi Gaza, Palestine, indicated that the Mediterranean component was the highest represented chorotype in most life forms. A data set of 41 stands was analyzed using multivariate techniques (TWINSPAN and DCA) to classify the vegetation of this wadi, and to determine the relationship between the identified plant communities and the prevailing environmental factors. Seven habitat types were distinguished and six plant communities represented by 12 indicator species were identified after TWINSPAN analysis. The axes of the DCA-ordination separated the halophytic species of the moist saline sites of the wadi bed from those of the relatively dry wadi terrace (along the soil moisture, salinity, chloride, carbonate, bicharbonate, silt and K gradients). The species diversity of the plant communities and habitat types were assessed and discussed.

照葉人工林の種多様化に関する研究

In order to find out the methods of increasing species richness of lucidophyllous-artificial forest, we investigated that forest in Nanko power station on littoral district, Osaka city. As the result of comparison of life form spectrum between lucidophyllous-artificial forest and lucidophyllous-natural forest, it became clear that lucidophyllous-artificial forest lacks in dwarf shrub, perenial herb, climber, epiphyte and others. The 693 plants of 44 species belonging to those life forms were planted on three testing sites as a seed sources in plant species flow for species richness in the forest from November 1999 to June 2002. We investigated growth condition of those plants. By the reason of little precipitation in summer in 2000, 2001 and 2002 or winter in 1999, 48% of the plants withered. The withering ratio of Cymbidium goeringii, Ardisia japonica, Ardisia crenata, Liriope platyphylla and others were low. It seemed that planting of dwarf shrubs and perenial herbs which had tolerance to aridity was effective, as a method of increasing species richness of lucidophyllous-artificial forest.

Floristic features of Damietta area in the north east Nile Delta, Egypt.

Floristic features of three habitat types in the Damietta Governorate namely: field crops, orchards and canal banks aredescribed. The study habitats include 171 species related to 128 genera, grouped under 44 families with Gramineaeattaining 36 species (21.05%), Compositae 21 species (12.28%) and Chenopodiaceae 15 species (8.77%), these arethe main families. The recorded species comprise 98 annual species (57.31%), 8 biennial species (4.68%) and 65perennial species (38.01%). The annual species are classified under three categories as follows: a) all year activeannuals (14 species, b) winter-spring active annuals (64 species) and c) summer-autumn active annuals (20 species).According to the life-form spectrum the recorded species are classified into: therophytes (60.23%),cryptophytes (22.22%), chamaeophytes (7.60%), hemicryptophytes (7.02%), nanophanerophytes (1.75%) andparasites (1.17%).The floristic analysis of the study area reveals that, the Mediterranean elements (mono, bi - pluriregional)include 81 taxa (47.36%), Cosmopolitan element 28 species (16.37%), Palaeotropical 22 species (12.68%) andPantropical 21 species (12.28%). These represent the major chorotypes. The other floristic categories are poorlyrepresented. This indicates that, the study area is obviously belong to the Mediterranean Territory with the enteranceof other elements to the area.

Elevational diversity of arrow bamboo (Fargesia spathacea) communities on Mount Shennongjia in Central China

Altitudinal changes in species richness, species diversity, species evenness, life-form spectrum, and community structure of arrow bamboo (Fargesia spathacea) were studied within 11 plots from 1 500 m to 2 600 m asl on Mount Shennongjia in Central China. From the lowest plot (1 680 m) to the highest one (2 570 m), vascular plants declined from 30 to 7 species, following a linear model ofY=55.99-1.83X (d.f.=9,F-value=48.64,r 2=0.84,P<0.001); species diversity, reduced from 3.13 to 1.78, following a linear model ofY=4.67–0.10X (d.f.=9,F-value=22.82,r 2=0.72,P=0.001); species evenness varied from 0.83 to 0.99, but presented little relationship to the altitude (r=0.112,P=0.742). In the life-form spectra, with the increase of altitude, the percentage of annual plants (r=0.60), underground bulb perennials (r=0.40), and big trees (r=0.35) tended to increase; shrubs (r=−0.52) and middle-sized trees (r=−0.45) tended to decline; perennial grasses (r=0.04) and semi-shrubs (r=0.03) were not strongly related to the altitudinal gradient. Arrow bamboo communities could be classified into five groups: bamboo under evergreen broad-leaved forest, under deciduous broad-leaved forest, under temperate coniferous forest, under cold-temperate coniferous and mixed forest, and pure bamboo community.

SEEING OURSELVES AS PRIMATES

There has been a marked expansion in our human knowledge in recent decades, and much of this new information about ourselves and our world has yet to be integrated into our human self-image. I maintain that understanding how we fit within the spectrum of lifeforms as the primates that we are will enable us to take a more active role in choosing ecologically responsible behavior and will allow us to address more effectively our major problems of overpopulation, overconsumption, and militarism.

Life-form spectra of Brazilian cerrado sites

Summary The cerrado, the second largest vegetation type in Brazil, presents a wide physiognomic range, from grasslands to tall woodlands, but with most of its physiognomies fitting the definition of tropical savanna. We compiled Raunkiaer’s life-form spectra from cerrado sites and from other vegetation types, comparing them among themselves with ordination analyses. In all cerrado life-form spectra, the main life-form classes were the hemicryptophytes and the phanerophytes, the former prevailing in sites with open physiognomies and the latter prevailing in sites with closed physiognomies. When compared with life-form spectra from other vegetation types, the cerrado sites formed a distinct group, with scores closer to those of the hemicryptophytes and phanerophytes. The cerrado sites distinguished themselves from the savanna sites by their under-representation of therophytes. The ordination plot indicated the likeliness of two gradients in the determination of biological spectra in the world, one from wet to dry, the other from hot to cold, thus stressing the role of precipitation and temperature on plant forms. Even if sometimes criticized in its application on tropical communities, Raunkiaer’s system was useful to characterize the cerrado floras and to separate them from other vegetation types.

Seeing Ourselves as Primates

There has been a marked expansion in our human knowledge in recent decades, and much of this new information about ourselves and our world has yet to be integrated into our human self-image. I maintain that understanding how we fit within the spectrum of lifeforms as the primates that we are will enable us to take a more active role in choosing ecologically responsible behavior and will allow us to address more effectively our major problems of overpopulation, overconsumption, and militarism.

The vegetation of ash disposal sites at Hendrina Power Station II: Floristic composition

An important component of any ecosystem is the species it contains. Species also serves as good indicators of the ecological condition of a system. A list of all species collected during the three-year period was therefore compiled together with their life form spectra. The floristic composition of the ash disposal area at Hendrina Power Station was also compared with the floristic composition of an adjacent natural grassland. A total of 278 species were identified of which 151 occurred on the ash disposal sites and 163 in the natural grassland. Of all the species, 35 occurred in both areas of which most were annual pioneer species. The species composition and life form spectra of the two areas were considerably different. Therophytes were, for example, more abundant on the ash disposal areas. The reconstruction of an ecosystem on ash disposal sites with a species composition similar to that of the natural grassland will require far more financial inputs and habitat amelioration than is presently the situation.

Ecology of the Pteridophytes on the Southern Slopes of Mt. Kilimanjaro. Part II: Habitat Selection

Abstract: Based on the evalutation of 957 vegetation plots on the southern slope of Mt. Kilimanjaro, habitat preferences for 140 species of pteridophytes were evaluated. Using the average percentage cover value, and taking into account the pteridophyte flora's composition, life form spectra and its spectra of seasonal growth pattern, eight vegetation formations were recognized. Ferns contributed less than 1 % of the vegetation cover of salt marshes, ruderal vegetation, grasslands and (sub‐)alpine heathlands. In contrast, pteridophytes constituted the most important vascular plant group on rocks, where 64 species were found, forming about two‐thirds of the vegetation cover. With respect to alpha and beta diversity and fern biomass, luxuriant montane forest was the main habitat for pteridophytes on Mt. Kilimanjaro. Here 130 pteridophyte species (93 % of the whole pteridophyte flora of the study area), on average, contributed 16 % of the total vegetation cover. Epiphytic ferns, tree ferns and filmy ferns had their main distribution between 1900 and 2400 m, in a zone coinciding with the maximum rainfall on Mt. Kilimanjaro's southern slope.Poikilohydrous species were typical of dry habitats, such as on rocks, in meadows or along roadsides, but they also occurred in the often sun‐exposed epiphyte layer in moist montane forests. Deciduous species, which were in many cases fire resistant, had a similar distribution; however, inside the forest belt they were restricted to the lower and upper parts, where fires are a common phenomenon. Evergreen species were the dominant group in swamps, forests and forest clearings.Compared to other volcanoes in East Africa, Mt. Kilimanjaro is distinctly richer in fern species in general and in filmy ferns, tree ferns and epiphytic ferns in particular, suggesting that the forest belt of the southern slope of Mt. Kilimanjaro is wetter than those of other high mountains in East Africa.

Community features ofIndocalamus wilsoni in the Shennongjia National Nature Reserve, China

Four vegetation types, namely coniferous and broadleaved mixed forest, secondary deciduous broadleaved forest, open shrubs and meadow, with dwarf bamboo (Indocalamus wilsoni) are compared on their floristic composition, life form, community structure, and survivorship of bamboos. Disturbance of conifer-logging two decades ago promoted the species diversity, but negatively influenced the survivorship of dwarf bamboo which is dominate on the forest floor. Open shrubs bear more species diversity and more geophytes in its life-form spectrum than its background vegetation subalpine meadow, however, dwarf bamboo is growing much better in the open shrubs than in the meadow. It seems dwarf bamboo probably favorites to occur in the vegetation at gentle slopes with a mediate canopy cover. Its mass flowering in the secondary deciduous forest suggests that a simultaneous flowering and following dieback maybe irrupt in the recently coming years over the subalpine Shennongjia in China, which will be not only alter the floristic composition and community structure of the old bamboo stands, but also influence the survivorship of this rare species.

Evaluation and monitoring of the flora in a nature reserve by estimation methods

We tested the use of non-parametric estimators of species richness to evaluate the flora of a relatively large (431 ha) nature reserve, using a sampling area much lower than that used in previous studies. Different estimation methods were applied to floristic data obtained from 50 random plots: the number of observed species, the extrapolated accumulation curves based on the Michaelis–Menten model and the non-parametric estimators based on incidence data (Chao2, first-order Jackknife, second-order Jackknife and bootstrap). To test the performance of the estimators, five data sets were created on the basis of life-forms. The estimates were compared with reference values obtained by traditional floristic and vegetation sampling. The power of the different estimation methods could not definitively be determined, but the first- and second-order Jackknives seem to be the most precise. Although total species richness was underestimated, the sample-based approach provided accurate information for quantitative comparison of time series of data related to ecological changes, vegetation dynamics and environmental changes. This sample-based data included basic statistics on species richness and species frequency distributions as well as the life-form spectrum, at the plot and the whole site scales.

Plant species diversity changes in abandoned chestnut (Castanea sativa) groves in southern France

Over the last few decades, marked land use changes have taken place in many Mediterranean ecosystems. For example, many chestnut groves in France are now abandoned and have turned into 'natural' coppice stands while others are now clear-cut every 10 or 15 years for wood. Species composition and life form diversity of the plant communities have changed markedly both in the abandoned groves and in the periodically clear-cut coppice stands. What are the consequences of these changes on biodiversity at local and regional scales, and what are the implications for 'new forestry' management intended to conserve biodiversity at the same time as it optimizes productivity and profitability? To answer these questions we studied plant species diversity in the understorey strata along a successional gradient including cultivated grove; abandoned grove; young (15 years old), medium (40 years), and old (>55 years) coppice stands. The results showed that species richness decreased quickly but not steadily along this gradient, but life-form spectra data highlighted that the high levels of plant species biodiversity in cultivated groves were due primarily to the large number of therophytes (annual plants). At a shorter time scale, we also studied the consequences of experimental clear-cutting on plant species biodiversity. Direct measurements over four years showed that species richness and diversity in the understorey increased in the first two years after clear-cutting, but decreased during the 3rd and 4th years. This decrease corresponded closely with a steady increase in Leaf Area Index of the forest canopy. These results have been used to suggest some possible ways to manage the biodiversity in these ecosystems.

Plant species richness responses to management practices in chestnut (Castanea sativa Mill.) forests and coppice stands in the Cévennes mountains (southern France)

We compared plant species diversity in cut (coppiced) and uncut (22 yrs old) chestnut stands of the Cévennes in southern France over a 6-year period by measuring species richness, Shannon-Weaver biodiversity index, Leaf Area Index (LAI), and life form spectra. Species richness increased six-fold immediately after the clear-cut from 5 species in the old coppice stand before the clear-cut to 30 species 2 years after the cut, but subsequently decreased over the 6-year period to reach 15-16 species in a 100 m" plot (n = 15). The Shannon-Weaver diversity index behaved like species richness. LAI increased during this period, but there were no statistically significant relationships between the diversity indices and LAI. The life form spectra were also greatly modified after the clear-cut. These changes mainly concerned the number of hemicryptophytes which increased significantly. This behavior is very different from that observed in old field succession where therophytes (annuals) are the first invaders of the open areas. Finally we discuss the consequences of various land use practices on the conservation of plant species diversity in these two types of chestnut dominated ecosystems.

COMPARATIVE STUDY ON THE PLANT LIFE OF TWO MEDITERRANEAN DELTAIC LAKES IN EGYPT دراسة مقارنة على حياة النبات فى اثنين من بحيرات الدلتا - مصر المطلة على ساحل البحر األبيض المتوسط

The terrestrial and aquatic flora of the two largest natural lakes of Egypt (Lake Manzala and Lake Burollos) were studied. Lake Manzala is located on the eastern side of Damietta branch of the Nile, whereas, Lake Burollos lies on the eastern side of Rosetta branch of the Nile, occupying the central position along the Mediterranean coast of the Nile delta . Despite the two times larger area of Lake Manzala compared with Lake Burollos and physiographic similarity, Lake Burollos is floristically rich (135 species, 41 families) as compared with Lake Manzala (102 species, 36 families). Both lakes have many floristic differences. Lake Burollos is characterized with lower number of euhydrophytes (7 species) compared to 16 species recorded in Lake Manzala. The highest number of species are belonging to Gramineae and Chenopodiaceae, respectively in both lakes. The life form spectrum of both lakes showed that therophytes are highly represented followed by geophytes . The islands in both lakes are floristically rich. However, islands of Lake Burollos seem to be suitable habitat for some plant species absent from the islands of Lake Manzala e.g. Lycium schweinfurthii, Pancratium maritimum, Allium roseum, Silene succulenta, Asparagus stipularis and several annuals, some plant species recorded in one site in Lake Burollos, are considered as rare species such as Ipomoea imperati and Limonium narbonense which are threatened and need protection . In the present paper, the authors compared the floristic composition of the different habitats of both lakes.

Flowering plant biodiversity of Augrabies Falls National Park: a comparison between Augrabies Falls National Park, Kalahari Gemsbok National Park, Vaalbos National Park and Goegap Nature Reserve

A list of flowering plants has been compiled for the Augrabies Falls National Park, which occupies an area of approximately 18 600 ha. This list of 364 species represents 210 genera and 74 families. The Monocotyledonae are represented by 76 species (20.9 of the total number of species) and the Dicotyledonae by 288 (79.1 ). Approximately 54 of these species occur only in the Augrabies Falls National Park and not in one of the other conservation areas with which it was compared. According to the life form spectrum, the Augrabies Falls National Park is a therophyte-hemicryp- tophyte area. Five of these spesies are endemic to the Southern African floristic region. One of them is a rare species.

Floristic composition and phytogeography in a Mediterranean deltaic lake (Lake Burollos), Egypt

The flora of twenty islands and eighty shoreline sites at Lake Burollos, Egypt, was surveyed and classified in terms of life form spectrum and phytogeography. Distribution and abundance values were determined. A total of 135 flowering plants species, in 41 families characteristic of the Mediterranean coastal region of Egypt was observed. Annuals (48.1%) and cryptophytes (32.8%) predominated. The mono-regional Mediterranean species constitute 10.4% of the other flora. Species which are primarily Mediterranean but in some cases bi-regional or pluri-regional account for 43.9%. The number of plant species recorded on the shorelines was relatively higher than that on islands within the lake. In contrast, aquatic macrophytes such as Najas marina v. armata and Ruppia maritima were restricted to the lake water and were absent in the drainage channels emptying into the lake.

Environmental correlates of species distribution in arid desert ecosystems of eastern Egypt

This paper gives a quantitative account of a recent study of vegetation–environment relationships along four transects crossing the northern part of the inland arid desert of Egypt. The vegetation data set was based on cover values from 200 stands; environmental analysis included percentages of surface sediments of different size classes, soil pH, total soluble salts, soil moisture, organic carbon and calcium carbonate. TWINSPAN classification and complementary DCA analysis of the data set yielded 21 vegetation clusters, assigned to six vegetation types dominated by 27 indicator species: some are characteristic of specific habitats, and others indicate transitions between groups of habitats. Application of Detrended Canonical Correspondence Analysis (DCCA) indicated that silt, clay, moisture content, organic carbon and calcium carbonate were the main abiotic environmental variables correlated with species distribution in the study area. A total of 141 plant species belonging to 32 different families were recorded in this study, mostly of Saharo-Arabian distribution, with therophytes followed by chamaephytes dominating the life-form spectra. High species richness was recorded in vegetation of sand plains, moist muddy flats and runnels, contrasting with salinized and limestone plains. Soil texture, organic carbon and moisture content are correlated with species diversity in the richer habitats, while high salinity and calcium carbonate are the main factors associated with lower species diversity.

Checklist das macrófitas aquáticas do Pantanal, Brasil

O Pantanal, por ser alagável, é ambiente favorável ao desenvolvimento de muitas plantas aquáticas. Para atender demandas de levantamentos florísticos regionais, fez-se a listagem das macrófitas aquáticas do Pantanal, com base em coletas depositadas nos Herbários CPAP (EMBRAPA), COR (Universidade Federal de Mato Grosso do Sul), CH (Universidade Federal de Mato Grosso) e K (Kew). Até o momento, foram levantadas 242 espécies, distribuídas em 106 gêneros e 54 famílias. As famílias mais numerosas são Poaceae (22 espécies), Cyperaceae(17), Leguminosae e Scrophulariaceae(14), Alismataceae e Onagraceae(13), Pontederiaceae(11), Lentibulariaceae(10), Characeae(9), emnaceae, Malvaceae e Nymphaeaceae(8). A maioria das demais famílias apresentam uma ou duas espécies cada. Quanto à forma biológica, 39% são plantas emergentes, 28% anfíbias, 11,5% flutuantes fixas, 8% flutuantes livres, 8% submersas fixas, 3,8% submersas livres e 1,7% epífítas. Os principais gêneros em número de espécies são Nymphaea, Utricularia, Echinodorus, Ludwigia, Polygonum, Aeschynomene, Cyperus, Eleocharis e Bacopa.

Species and life-forms composition of Mediterranean mountain pastures in two years of contrasting precipitation

Summary Twenty sites, representing different pasture types in NW Spain, were sampled with respect to their floristic composition and structural characteristics for two years of contrasting precipitation. The first year was characterised by a severe regional drought and the second year had normal precipitation. Four plant community types were identified by consensus classification techniques of plant species composition. These community types were associated with grazing regime, percentage cover of herbaceous vegetation, rocks and bare ground, and soil characteristics. One community type included mesic sites on acidic parent materials with low grazing, whereas the other three were all intensely grazed, and included either xeric or mesic sites on calcareous parent materials, or mesic sites on acidic parent materials. Species composition varied between years according to well defined directional trends within the intensely grazed communities. Compositional differences between calcareous and acidic pastures increased in the normal year. On average 49 to 73% of the species appeared only in one year. This high species turnover was also high when analysed separately for different life-forms, namely annuals, perennial grasses, perennial forbs and undershrubs. In spite of this, both the life-form spectrum, and the relative abundance of each life-form remained unaltered for each community type in both years. This suggests that such characteristics of the communities' structure are in equilibrium with habitat characteristics, as well as the existence of a deterministic structure in the grasslands studied.