Configurational crop heterogeneity increases within‐field plant diversity

Abstract The aim of this study is to differentiate old-field plant communities along the abandonment time and/or environmental gradient in the landscape surrounded villages with established Czech settlers in Romanian Banat area conserving traditional agriculture, and to identify site factors which cause plant diversity of particular vegetation types. Study area: Wider territory centered by the village Sfânta Elena, southern Romania ((44°40’ N; 21°43’ E). Methods: We collected 97 phytosociological relevés covered the same number of old-fields in the area and the following habitat parameters were measured: soil pH, available phosphorus, total carbon and nitrogen, Heat Load Index. Software TURBOVEG / JUICE was used to collect and elaborate the data set of relevés. Old-field vegetation was classified into five basic plant communities using TWINSPAN (all the botanical material includes 291 plant species). For each community, we detected diagnostic species according to their fidelity index. The presence of mowing, grazing or burning was registered for recorded stands. Ecological preferences of each community were examined using one-way analysis of variance (ANOVA). Vegetation-environment relationships were analysed using ordination method – Cannonical correspondence analysis (CCA) in CANOCO for Windows (version 4.5) to find the main variability gradients within the dataset. Scatter plot relationships between variables were constructed. Main results and conclusions: Dependence of number of species (alpha diversity) on the abandoned field’s age exhibits an unimodal shape of this relationship with the maximum peak of species diversity in plant stands aged approximately 13 years. The most importnat ecological factors and/or type of management in the relationship to the old-field plant composition show the following significance order: available phosphorus content in the soil (P), total nitrogen content in the soil (N), presence of burning, length of abandonment (old-field age), carbon/nitrogen ratio in the soil (C/N). Other parameters (grazing, mowing, zero management) do not demonstrate effective impact according to our dataset and seem to be equal to the absence of burning.

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Plant diversity and species richness of Ljubljana marsh grasslands under the influence of different cutting and fertilizing regimes

Acta Agronomica Hungarica ◽

10.1556/aagr.57.2009.2.11 ◽

2009 ◽

Vol 57 (2) ◽

pp. 197-203 ◽

Cited By ~ 2

Author(s):

T. Sinkovč

Keyword(s):

Species Richness ◽

Plant Diversity ◽

Grassland Management ◽

Botanical Composition ◽

Significant Negative Effect ◽

Negative Effect ◽

Cutting Regimes ◽

N Rates ◽

Exploitation Intensity ◽

Plot Design

The botanical composition of grasslands determines the agronomic and natural values of swards. Good grassland management usually improves herbage value, but on the other hand it frequently decreases the plant diversity and species richness in the swards. In 1999 a field trial in a split-plot design with four replicates was therefore established on the Arrhenatherion type of vegetation in Ljubljana marsh meadows in order to investigate this relationship. Cutting regimes (2 cuts — with normal and delayed first cut, 3 cuts and 4 cuts per year) were allocated to the main plots and fertiliser treatments (zero fertiliser — control, PK and NPK with 2 or 3 N rates) were allocated to the sub-plots. The results at the 1 st cutting in the 5 th trial year were as follows: Fertilising either with PK or NPK had no significant negative effect on plant diversity in any of the cutting regimes. In most treatments the plant number even increased slightly compared to the control. On average, 20 species were listed on both unfertilised and fertilised swards. At this low to moderate level of exploitation intensity, the increased number of cuts had no significant negative effect on plant diversity either (19 species at 2 cuts vs. 20 species at 3 or 4 cuts). PK fertilisation increased the proportion of legumes in the herbage in the case of 2 or 3 cuts. The proportion of grasses in the herbage increased in all the fertilisation treatments with an increased numbers of cuts. Fertiliser treatment considerably reduced the proportion of marsh horsetail ( Equisetum palustre ) in the herbage of the meadows. This effect was even more pronounced at higher cut numbers. The proportion of Equisetum palustre in the herbage was the highest in the unfertilised sward with 2 cuts (26.4 %) and the lowest in the NPK-fertilised sward with 4 cuts (1.4%).

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