Significant part of our work was developing a new type of CO2 and H2O gas exchange chambers fit for measuring stand patches. Ground areas of six chambers (ranged between 0.044-4.531 m2) constituted a logarithmic series with doubling diameters from 7.5 to 240.0 cm. We demonstrate one of the first results for stand net ecosystem CO2 exchange (NEE) rates and temporal variability for two characteristic Central European grassland types: loess and sand. The measured mean NEE rates and their ranges in these grasslands were similar to values reported in other studies on temperate grasslands. We also dealt with the spatial scale dependence from ecophysiological point of view. Our chamber-series measurement was performed in a perennial ruderal weed association. The variability of CO2-assimilation of this weed vegetation showed clear spatial scale-dependence. We found the lowest variability of the vegetation photosynthesis at the small-middle scales. The results of spatial variability suggest the 0.2832 m2 patch size is the characteristic unit of the investigated weed association and there is a kind of synphysiological minimi-area with characteristic size for each vegetation type. and Sz. Czóbel ... [et al.].
The distribution and number of colonies of rooks Corvus frugilegus L. was studied over a three-year period in a landscape in eastern England dominated by winter cereals. Individual rookeries were generally small and not evenly distributed, with a total of 1561– 1637 nests in a 325 km2 study area over the three years. The distribution of groups of rookeries (main colony with satellites) was associated with the amount of grassland, a colony of 100 nests requiring some 122 ha of grass within 1 km. Feeding habitat and preferences of rooks were studied throughout one year. The most consistently used feeding habitat was grassland and it was strongly preferred, with a peak in June. Winter cereals were used from October to March, but were never preferred, other crops being used seasonally. Flock size peaked in February and was smallest during the breeding season, when the mean distance of feeding flocks from the colony was less than 1 km. Increases in land given over to horses, riding and turf production could benefit rooks in the study area.
To determine the effectiveness of rehabilitation on improving ecosystem functions, we examined net photosynthetic rate (PN), tree species composition, soil enzyme activities, and the microclimate (air and soil temperature, relative humidity) of an area on Mt. Makiling that has been rehabilitated and protected from fire for over 12 years. After it was last burned extensively in 1991, restoration was initiated by planting Acacia mangium and Acacia auriculiformis. We selected three areas to study in 2003. Two areas were rehabilitated with A. mangium and A. auriculiformis, and one was still dominated by Imperata cylindrica and Saccharum spontaneum. PN of A. mangium and A. auriculiformis showed significantly lower values than those of I. cylindrica and S. spontaneum. The Acacia plantations had more naturally regenerated tree species than the grassland. Additionally, more tree species appeared in the A. mangium plantation than in the A. auriculiformis plantation. Ficus spetica was present in all of the study sites. Dehydrogenase and phosphatase activities were significantly higher in soil under the Acacia plantations than under grassland. Grassland showed higher air temperature, relative humidity, and soil temperature as well as a larger variation per hour in these parameters compared to the Acacia plantations. The highest air temperature, relative humidity, and soil temperature were measured in April during the dry season. From the regression analysis, soil temperature was significantly correlated with air temperature. Hence plantations, as a rehabilitation activity for grassland, promote natural regeneration and stabilize the microclimate. This stabilization of the microclimate affects establishment and growth of naturally occurring tree species. and Y. K. Lee ... [et al.].
Seedlings of four tree species (Bischofia javanica, Dracontomelon dao, Erythrina orientalis, and Pterocarpus indicus) were planted in flat and sloping grassland in plantation sites established in May 2002 in the La Mesa watershed, Philippines. Tree growth and net photosynthetic rate (PN) were monitored. The height, diameter at the root collar, and PN of the four species grown in the sloping grass site were larger than those of seedlings grown in the flat grass site. In addition, soil moisture contents in the sloping grass site were higher than those of the flat grass site. Growth of the four species was probably strongly associated with microenvironments (e.g. air temperature) in both tested sites. and S.-Y. Woo, D. K. Lee, Y.-K. Lee.
The creation of improved areas is one way of increasing the productivity of livestock on Cantabrian heathland (NW Spain), a habitat that is frequently located in less favourable mountainous areas where the development of sustainable husbandry is limited. The effect of this on the biodiversity of heathland is unclear and likely to depend on several factors, such as the grazing regime. In order to clarify this situation, the effects of type of vegetation, species of grazer and grazing regime on the composition of the ground-dwelling arthropod fauna of partially improved heathland were determined. The effects of grazing by cattle or sheep and two grazing regimes (cattle or sheep, or both of them together with goats) were studied in eight plots (two replicates per treatment). Each plot included two types of vegetation, gorse (Ulex gallii)-dominated shrubland and improved grassland (Lolium perenne-Trifolium repens). Arthropods were surveyed using pitfall traps. Overall, the composition of the arthropod fauna did not differ between plots grazed by different species of grazer or using different grazing regimes but was significantly associated with the type of vegetation. Most of the opilionids and several carabids clearly preferred shrubland, while lycosids and various carabids were mainly associated with grassland. While the species of grazer affected the faunal composition of grassland, grazing regime was more important in shrubland. Arthropod responses to the grazing treatments were determined by the grazing behaviour of the large herbivores and the habitat requirements of each arthropod taxon. The great structural heterogeneity of the vegetation and the more microhabitats in shrubland grazed by mixed flocks was mainly a result of the goats preferring to browse on the woody vegetation in these areas. The grazing by either sheep or cattle had less of an affect on the fauna of shrubland than grassland. and Rocío ROSA GARCÍA, Urcesino GARCÍA, Koldo OSORO, Rafael CELAYA.
Longer term monitoring of soil water content at a catchment scale is a key to understanding its dynamics, which can assist stakeholders in decision making processes, such as land use change or irrigation programs. Soil water monitoring in agriculturally dominated catchments can help in developing soil water retention measurements, for assessment of land use change, or adaptation of specific land management systems to climate change. The present study was carried out in the Pannonian region (Upper-Balaton, Hungary) on Cambisols and Calcisols between 2015 and 2021. Soil water content (SWC) dynamics were investigated under different land use types (vineyard, grassland, and forest) at three depths (15, 40, and 70 cm). The meteorological data show a continuous decrease in cumulative precipitation over time during the study with an average of 26% decrease observed between 2016 and 2020, while average air temperatures were similar for all the studied years. Corresponding to the lower precipitation amounts, a clear decrease in the average SWC was observed at all the land use sites, with 13.4%, 37.7%, and 29.3% lower average SWC for the grassland, forest, and vineyard sites, respectively, from 2016 to 2020 (measured at the 15 cm depth of the soil). Significant differences in SWC were observed between the annual and seasonal numbers within a given land use (p < 0.05). The lowest average SWC was observed at the grassland (11.7%) and the highest at the vineyard (28.3%). The data showed an increasing average soil temperature, with an average 6.3% higher value in 2020 compared to 2016. The grassland showed the highest (11.3 °C) and the forest soil the lowest (9.7 °C) average soil temperatures during the monitoring period. The grassland had the highest number of days with the SWC below the wilting point, while the forest had the highest number of days with the SWC optimal for the plants.
We investigate orthopteran communities in the natural landscape of the Russian Far East and compare the habitat requirements of the species with those of the same or closely related species found in the largely agricultural landscape of central Europe. The study area is the 1,200 km2 Lazovsky State Nature Reserve (Primorsky region, southern Russian Far East) 200 km east of Vladivostok in the southern spurs of the Sikhote-Alin Mountains (134°E/43°N). The abundance of Orthoptera was recorded in August and September 2001 based on the number present in 20 randomly placed 1 m2 quadrates per site. For each plot (i) the number of species of Orthoptera, (ii) absolute species abundance and (iii) fifteen environmental parameters characterising habitat structure and microclimate were recorded. Canonical correspondence analysis (CCA) was used first to determine whether the Orthoptera occur in ecologically coherent groups, and second, to assess their association with habitat characteristics. In addition, the number of species and individuals in natural and semi-natural habitats were compared using a t test. A total of 899 individuals of 31 different species were captured, with numbers ranging between 2 and 13 species per plot. Species diversity was higher in semi-natural habitats than natural habitats. There was a similar but non-significant pattern in species density. Ordination analysis indicated four orthopteran communities, which were clearly separable along a moisture and vegetation density gradient. The natural sites in the woodland area of the Lazovsky Zapovednik are characterized by species-poor and low-density orthopteran assemblages compared to the semi-natural sites. But, the natural sites have a higher diversity of habitat specialists. Our findings corroborate the hypothesis that intermediate habitat disturbance levels support particularly species-rich animal communities at high densities. Under such regimes, orthopterans presumably mostly profit from the high diversity in plant species, which generates great structural and microclimatic heterogeneity.
The net photosynthetic rate (PN), transpiration rate (E), and water use efficiency (WUE) of two divergent Leymus chinensis populations from the grassland region of Northeast China were compared. The two populations experienced the similar habitats, but differed in leaf colour, stomata numbers, and chlorophyll contents. The leaf PN for the grey-green (GG) population was greater than that for the yellow-green (YG) population, while the leaf E for GG population was lower than that for the YG population. The greater WUE for the GG population suggests that this type is more able to maintain higher PN under drought and is more fit for the rangeland use in this climate region. and R. Z. Wang, Q. Gao.
Photosynthetic pathway type, based on 5*^C measurements, was determined for 48 species in 39 genera and 15 families of flowering plants from the grassiand region of Northeast China. Of this total, 10 species in 10 genera from 4 families were found to háve C4 photosynthesis; 38 species in 29 genera from 13 families had C3 photosynthesis. One C4 species in the Chenopodiaceae and three in the Gramineae had not been previously docnmented in the literatuře. The C4 species were most frequent in disturbed habitats, meadow steppe and šalině grassiand; C3 species dominated the other habitats sampled.
Plants’ abilities to function are difficult to evaluate directly in the field. Therefore, a number of attempts have been made to determine easily measurable surrogates – plant functional traits (PFTs). In particular, the value of PFTs as tools for predicting vegetation responses to management (i.e., grazing and mowing) is the focus of a large number of studies. However, recent studies using PFTs to predict the effect of pasture management in different regions did not give consistent predictions for the same set of PFTs. This lead to the suggestion that more specific traits better suited for a specific region be used in the future. We consider the identification of the most adaptative traits for surviving grazing and mowing in different biomes an important goal. Using temperate grasslands in Europe as an example, we show that (i) plant height, often considered as the best predictor of species response to grassland management, is coupled with other more relevant functional traits, and that (ii) clonal traits have important, often neglected functions in the response of species to grassland management. We conclude that single traits cannot be the only basis for predicting vegetation changes under pasture management and, therefore, a functional analysis of the trade-off between key traits is needed.