Cyperus-dominated vegetation in the eastern Po river

The ephemeral vegetation dominated by Cyperus sp. pl. was surveyed and analyzed along the eastern trait of the Po River (Po Plain, Italy). Two formerly described communities were recognized: Cyperetum esculenti and Amaranthus tuberculatus-phytocoenon. A third greater cluster is assigned to a new association: Cyperetum micheliano-glomerati. It is characterized by Cyperus glomeratus, C. michelianus, C. odoratus and C. squarrosus, that have been detected on over 75 % of the relevés. The main floristic and ecological traits of these detected vegetation types are discussed.

The environmental forming and productional functions of the haloxylon aphyllum in the Karnabchul desert

We have conducted investigation of the environmental function of the desert tree of black saxaul (Haloxylon aphyllum) in the Karnabchul desert. As a result, it was found that different age plants of black saxaul had different effects on the degree of illumination. The greatest influence on the intensity of solar radiation was exerted by the saxaul plant of the black middle-aged state, the least the old generative individuals. Saxaul black had a significant impact on the temperature of the air: in the daytime, especially in the period 13-16 h, reducing the temperature under the crown and on the edge of the crown, and at night increasing it in the same areas. It also had a noticeable effect on the temperature of the soil. The temperature of the soil surface under the crown at night is higher, and during the day the warming was slower than in the outer part of the saxaul crown. Under the influence of black saxaul and soil moisture changed. Under the saxaul crown soil moisture is significantly higher compared to the control (open natural pastures). The highest soil moisture was observed in the upper soil layers at the base of the saxaul trunk. As a result, under the environmental action of black saxaul more favorable hydrothermal conditions for the growth and development of natural wormwood-ephemeral vegetation under the protection of strips and adjacent areas of pastures are formed. The result of production activities chemotaxonomic postbestowal bands consists of two following components: production of fodder mass of the Haloxylon and fodder productivity of wormwood-ephemeral vegetation of natural pastures. By increasing the yield of natural pastures under the protection of pasture protection strips and the harvest of the black saxaul fodder productivity of desert pastures increases more than twice.

The phytogenic effect of different-aged black saxaul plants on the productivity of wormwood-ephemeral vegetation under the conditions of Karnabchul

The aim of the study is to determine the effect of different-age black saxaul plants on the productivity of wormwood-ephemeral vegetation through the study of the phytogenic field of this ephemeroid species. The phytogenic field of black saxaul has been studied by the phytomer method in the desert Karnabchul. The study showed that its influence in the minimum phytogenic field on the productivity of wormwood-ephemeral vegetation is negative, in the external part of the phytogenic field on bluegrass and forbs is positive, and on wormwood and sedge remains negative. The highest productivity indices are observed in them between the outer and inner and outer parts of the phytogenic field of the middle-aged generative plants of the edificator.

Recent increase in aerosol loading over the Australian arid zone

Collocated sun photometer and nephelometer measurements at Tinga Tingana in the Australian Outback over the decade 1997–2007 show a significant increase in aerosol loading following the onset of severe drought conditions in 2002. This increase is confined to the season of dust activity, particularly September to March. In contrast, background aerosol levels during May, June and July remained stable. The enhanced aerosol loadings during the latter 5 years of the study period can be understood as a combination of dune destabilisation through loss of ephemeral vegetation and surface crust, and the changing supply of fluvial sediments to ephemeral lakes and floodplains within the Lake Eyre Basin. Major dust outbreaks are generally highly localised, although significant dust activity was observed at Tinga Tingana on 50% of days when a major event occurred elsewhere in the Lake Eyre Basin, suggesting frequent basin-wide dust mobilisation. Combined analysis of aerosol optical depth and scattering coefficient shows weak correlation between the surface and column aerosol (R2=0.24). The aerosol scale height is broadly distributed with a mode typically between 2–3 km, with clearly defined seasonal variation. Climatological analysis reveals bimodal structure in the annual cycle of aerosol optical depth, with a summer peak related to maximal dust activity, and a spring peak related to lofted fine-mode aerosol. There is evidence for an increase in near-surface aerosol during the period 2003–2007 relative to 1997–2002, consistent with an increase in dust activity. This accords with an independent finding of increasing aerosol loading over the Australian region as a whole, suggesting that rising dust activity over the Lake Eyre Basin may be a significant contributor to changes in the aerosol budget of the continent.

Association Dichostylidi—Heleochloetum alopecuroidis (Tímár 1950) Pietsch 1973 (Isoёto-Nanojuncetea) in Volga river delta

Bank communities of ephemeral vegetation, co-dominated by Dichostylis micheliana and Cyperus fuscus, were found in the Volga River delta within the area of Astrakhan city and the Astrakhan biosphere reserve in October 2004. They were identified as belonging to the ass. Dichostylidi—Heleochloetum alopecuroidis (Tímár 1950) Pietsch 1973 (Heleochloo—Cyperion micheliani, Cyperetalia fusci, Isoёto-Nanojuncetea), described from Hungary. The Astrakhan stands can be distinguished as a new subassociation D.—H. a. riccietosum frostii Taran subass. nov.

Implementing Satellite-Based Grazing Gradient Methods for Rangeland Assessment in South Australia.

This paper reports on a project to adapt grazing gradient methods, which use satellite data, to assess the condition of the northern rangelands of South Australia. Within this region, cattle graze in large paddocks on mainly ephemeral vegetation that responds in often unpredictable ways to erratic rainfall. Two methods were tested: one calculates average cover levels at increasing distance from watering points while the other produces a map showing where vegetation response to rainfall is different to that which might be expected. Before using the methods, it was necessary to rapidly produce a map of landscape types reflecting grazing preference and we show how this was obtained from classified satellite data. It was not possible to derive an accurate index of vegetation cover from the satellite data for areas with a dark stone mantle and these areas were excluded from grazing gradient analyses. We describe how analysis software was adapted to the needs of a client (SA Department of Environment and Natural Resources) and how training was provided. Testing of the grazing gradient technology as a suitable method for determining lease condition in northern South Australia is continuing and is supported by both pastoralists in the region and the Pastoral Board. Key words: land condition, pastoral lease assessment, satellite data, thematic mapper, grazing gradients, technology transfer

Miscellaneous notes

DESCRIPTIVE ECOLOGICAL ACCOUNT OF INTENSIVE SPRING FLOWERING OF EPHEMERAL VEGETATION IN THE BOSHOF AREA, ORANGE FREE STATE, SOUTH AFRICA