scholarly journals Changes within oribatid mite communities associted with Scots pine regeneration

Web Ecology ◽  
2000 ◽  
Vol 1 (1) ◽  
pp. 76-81 ◽  
Author(s):  
J. A. Horwood ◽  
K. R. Butt

Abstract. Compositions of oribatid mite communities were compared under five stages of native Scots pine regeneration (spanning 100 yr) within the Abernethy Forest Reserve, U.K. Sampling was conducted during autumn and spring, and oribatid mites identified using the morphospecies technique. Results showed the oribatid mite fauna to be abundant and diverse. Density of mites generally decreased with soil depth, however in the woodland sites the upper 10 cm of soil contained more individuals than the litter layer. Eleven morphospecies showed significant differences (p < 0.05) in abundance between sites, with marked preferences shown for either mature woodland or tree-less moorland. During spring, morphospecies richness and mite density were highest at the woodland sites, but during autumn they were greater at the moorland sites. Shannon Wiener diversity indices and measures of evenness, calculated for each site, showed that despite having a high morphospecies richness, sites were often dominated by a few very abundant morphospecies. A greater number of mites were collected during autumn, but only one morphospecies showed significant seasonal differences in numbers. Factors influencing differences in oribatid communities at each site are discussed and the use of morphospecies as an identification tool is also assessed.

Author(s):  
Rebeka Šķērstiņa ◽  
Uģis Kagainis

Abstract Prescribed burning is used to maintain and restore habitats, to protect and increase species bio-diversity. Knowledge about soil fauna is limited, especially on community responses to fire disturbances. The aim of this study was to determine the immediate effects of prescribed burning on soil armoured mite (Acari: Oribatida) communities, vegetation cover and soil physiochemical properties in a boreal Scots pine forest in Latvia. Soil samples were collected on the day of the prescribed burning in the protected landscape area “Ādaži” and 16 days after. No significant changes in abiotic factors were found. Fire significantly decreased the vegetation cover. After the burning, the total number of oribatid mites decreased by 93%, and the number of species by 77%. Changes in oribatid mite communities were significantly influenced by fire severity. The number of individuals decreased among all taxa, except Brachychthonioidea spp. and Cosmochthonius lanathus. A significant decrease in abundance was observed in previously abundant species — Suctobelbella spp., Oppiella nova and Tectocepheus velatus. After the burning, Suctobelbella spp. was an eudominant and Tectocepheus spp. was a dominant genus.


1992 ◽  
Vol 57 ◽  
Author(s):  
D. Maddelein ◽  
N. Lust

The  study of a seventy years old stand of Scots pine on drift sands proves that  Scots pine growth on these sites was and is still relatively good: average  diameter 27.6 cm, average height 19.4 m, standing volume 213 m3 and an annual increment  of 4.9 m3.ha-1.yr-1. All Scots pines  belong to the upper storey. Yet considerable differences in crown development  and vitality are observed. The current growth rate and the spontaneous  settlement of pine seedlings under canopy show the ideal conditions for the  creation of a high forest with reserves. Anyway a rotation period of more  than 70 years is recommendable.     On several places a consolidated regeneration of Scots pine seedlings under  canopy occur. Groups with a stem number of 700 to 3,500 seedlings per are, ranging  in age from 3 to 11 years and in height from 10 to 170 cm, are present. This  Scots pine regeneration has developed in a normal mor humus layer and in a  dense Deschampsia mat.      Broadleaved regeneration is not so abundant, and consists for 75 % of black  cherry. Absence of seed trees, browsing damage and the exclusive character of  black cherry are the limiting factors for the installation and survival of  valuable indigenous species, such as pedunculate oak.     Provided that black cherry is removed and that the regeneration is  protected against wild damage, it is possible to create a mixed forest  dominated by Scots pine but with a considerable admixture of indigenous  broadleaved trees. However, if black cherry will not be sufficiently  controlled, it can be expected that in a first phase black cherry will  dominate the understorey, that it will prevent the regeneration of all other  species and that, very soon, it will form an almost single-species dominated  stage in forest succession.


Koedoe ◽  
1997 ◽  
Vol 40 (2) ◽  
Author(s):  
C.M. Smit ◽  
G.J. Bredenkamp ◽  
N. Van Rooyen ◽  
A.E. Van Wyk ◽  
J.M. Combrinck

A vegetation survey of the Witbank Nature Reserve, comprising 847 hectares, was conducted. Phytosociological data were used to identify plant communities, as well as to determine alpha and beta diversities. Eleven plant communities were recognised, two of these are subdivided into sub- communities, resulting in 14 vegetation units. These communities represent four main vegetation types, namely grassland, woodland, wetland and disturbed vegetation. Grassland communities have the highest plant diversity and wetland vegetation the lowest. Floristic composition indicates that the vegetation of the Rocky Highveld Grassland has affinities to the grassland and savanna biomes and also to the Afromontane vegetation of the Great Escarpment. An ordination scatter diagram shows the distribution of the 14 plant communities or sub-communities along a soil moisture gradient, as well as along a soil depth/surface rock gradient. The sequence of communities along the soil moisture gradient is used for calculating beta-diversity indices. It is concluded that the relatively small size of the Witbank Nature Reserve is unlikely to have significant negative effects on the phytodiversity of the various plant communities. This nature reserve is therefore of considerable importance in conserving a representative sample of the Rocky Highveld Grassland.


Author(s):  
G. O. Ateh ◽  
M. G. Saka ◽  
E. E. Dishan ◽  
B. B. Meer

This study evaluated the relationship between selected physicochemical properties and microbial populations of the soil of Bagale Forest Reserve, Girei Local Government Area of Adamawa State, Nigeria. Five plots of 20 x 20 m were laid. Soil samples were collected from five different positions at two soil depths of 0-15 cm and 15-30 cm. The soil samples were isolated in the laboratory for microbial populations and determination of physical and chemical properties. The results obtained revealed that fungal population (7.65 x 105 cfu/ml) was the highest at the soil depth of 0-15 cm, representing 39% of the total microbial populations in the sampled soil of the study area. The results further revealed that the population (6.84 x 105 cfu/ml) of the bacteria had a positive effect on soils of the study area in terms of nitrogen fixation by Rhizobacterial spp. Chemical properties of the soil samples revealed that the available phosphorus exhibited the highest percentage (61.7%) at 0-15 cm soil depth. Analyses of soil physical properties recorded the highest percentage (49.0%) of sand at 0-15 cm soil depth. A similar percentage (50.0%) of sand was exhibited at the depth of 15-30 cm. These percentages accounted for the high porosity (29.0%) of the soil observed at the two soil levels in the study area and could be improved through the application of lime fertilizers. Application of appropriate fertilizers like NPK to improve the soil condition of the study area is highly recommended.


2018 ◽  
Vol 169 (5) ◽  
pp. 269-278
Author(s):  
Barbara Moser ◽  
Christoph Bachofen ◽  
Thomas Wohlgemuth

Pine regeneration: plasticity and acclimation in a dryer climate Increasing summer drought might limit the natural regeneration of Scots pine stands at low elevations of the Rhone valley. Common garden experiments at the forest-steppe ecotone have shown that emergence and establishment of Scots pine primarily depend on spring precipitation and, to a minor degree, on summer drought and rising temperatures. Scots pine seedlings acclimated rapidly to drought periods by favouring root to shoot growth. In the second year, the saplings were already adapted to drought so that most of them survived an extended spring and summer drought, as recorded at Sion twelve times during the last 154 years. Only an extreme summer drought – no water from June to September – killed 14.7% of the Scots pine saplings. Surprisingly, they were even able to acclimate to such extreme drought events: after the same extreme summer drought in the third year, mortality dropped below 5%. In general, the Scots pine was very plastic, i.e. seedlings and saplings changed their phenotype depending on environmental conditions. But we also found genetic adaptation: Scots pine originating from regions with pronounced summer drought, including populations from lower elevations in the Rhone valley, produced more biomass than those from moister regions in all treatment combinations. Black pine reacted similarly to the treatments like Scots pine, but it grew faster and more saplings survived the first extreme summer drought. These results show that Scots pine from low elevations of the Rhone valley is one of the most drought-tolerant provenances in Europe. Thanks to its high phenotypic plasticity and the ability of seedlings and saplings to acclimate to drought on a short time scale, natural regeneration of Scot pine at low elevations of the Rhone valley is likely to occur also under future conditions, but maybe less frequent than today.


2019 ◽  
Vol 45 (4) ◽  
pp. 181-188
Author(s):  
Maka Murvanidze ◽  
Levan Mumladze ◽  
Nino Todria ◽  
Meri Salakaia ◽  
Mark Maraun

2011 ◽  
Vol 48 (2) ◽  
pp. 177-183 ◽  
Author(s):  
Stanisław Seniczak ◽  
Sławomir Kaczmarek ◽  
Anna Seniczak

Oribatid mites (Acari, Oribatida) of bushy patches in steppe vegetation of cape Tarkhankut in Crimea (Ukraine)The density, species number, and age structure of oribatid mites were investigated in bushy patches (elm, hawthorn, hawthorn with rose) in steppe vegetation of cape Tarkhankut (Crimea). In these patches, the density of mites in shrub litter, herbs and moss was higher, but species number was similar like in open steppe vegetation. Hawthorn increased the density distinctly more than hawthorn with rose or bushy elms. In bushy patches, the samples of moss were richer in mites than samples of shrub litter alone or with herbs. Among oribatid mites,Chamobatesc.f.spinosusandTrhypochthonius tectorumwere most abundant, but relatively abundant and common were alsoTectocepheus velatus, Oribatulasp. 1,Achipteria nitens, andBrachychthonius berlesei. In oribatid mite communities, adults dominated, but the age structure of populations greatly depended on vegetation type.


2004 ◽  
Vol 34 (5) ◽  
pp. 998-1006 ◽  
Author(s):  
Zoë Lindo ◽  
Suzanne Visser

The effects of partial and clear-cut harvesting on abundance and community composition of forest floor microarthropods and oribatid mites were investigated in conifer and deciduous stands of the mixedwood boreal forest. Soil samples from clearcuts, strip-cut corridors in a partial cut, green-tree retention patches in a partial cut, and uncut control sites were collected 2.5 years after harvest and microarthropods were extracted, enumerated, and identified. Densities of microarthropod suborders were lower in the strip-cut corridors of the deciduous stands and significantly lower in the suborder Oribatida (oribatid mites). Changes in microarthropod community composition, decreased relative abundance of prostigmatid mites, and increased relative abundance of mesostigmatid mites were observed in corridor and clear-cut treatments. Lowered abundances and changes in community composition are likely due to compaction of the forest floor during harvesting. Selected oribatid mite species showed significantly lower abundances in clearcuts than in uncut sites, but diversity indices for oribatid mites were generally not significantly different between uncut sites and clearcuts. Changes in oribatid mite communities following harvesting were thus more quantitative (absolute abundance) than qualitative (diversity, composition), and as a result, use of oribatid mites as biological indicators of disturbance is limited because of the lack of changes in species composition.


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