Management Intensity and Topography Determined Plant Diversity in Vineyards

<div><p>Vineyards are amongst the most intensive forms of agriculture often resulting in simplified landscapes where semi-natural vegetation is restricted to small scattered patches. However, a tendency toward a more sustainable management is stimulating research on biodiversity in these poorly investigated agro-ecosystems. The main aim of this study was to test the effect on plant diversity of management intensity and topography in vineyards located in a homogenous intensive hilly landscape. Specifically, this study evaluated the role of slope, mowing and herbicide treatments frequency, and nitrogen supply in shaping plant diversity and composition of life-history traits. The study was carried out in 25 vineyards located in the area of the Conegliano-Valdobbiadene DOCG (Veneto, NE Italy). In each vineyard, 10 plots were placed and the abundance of all vascular plants was recorded in each plot. Linear multiple regression was used to test the effect of management and topography on plant diversity. Management intensity and topography were both relevant drivers of plant species diversity patterns in our vineyards. The two most important factors were slope and mowing frequency that respectively yielded positive and negative effects on plant diversity. A significant interaction between these two factors was also demonstrated, warning against the detrimental effects of increasing mowing intensity on steep slope where plant communities are more diverse. The response of plant communities to mowing frequency is mediated by a process of selection of resistant growth forms, such in the case of rosulate and reptant species. The other two management-related factors tested in this study, number of herbicide treatments and N fertilization, were less influential. In general, our study corroborates the idea that some simple changes in farming activities, which are compatible with grape production, should be encouraged for improving the natural and cultural value of the landscape by maintaining and improving wild plant diversity.</p> </div

Study area and distribution of the 25 vineyards in the Treviso province (NE Italy).

<p>Study area and distribution of the 25 vineyards in the Treviso province (NE Italy).</p

Relationship between the cover of rosulate and reptant species and species evenness.

<p>The line indicates a significant linear regression (P<0.01, R²=47.9).</p

Interaction between vineyard slope and mowing frequency.

<p>The fitted line is a general linear model estimate while the dashed lines indicated the intervals of confidence (95%). The tick marks on the x-axis showed the values of the explanatory variables. Panels were drawn using the “effect” function from the library “effects” in R.</p

Representative <i>Arabidopsis</i> root hairs distribution.

<p>The morphology on maturation zone is compared among the six clusters to a) non-inoculated roots and e) 50 nM IAA-treated seedlings. b) seedling roots grouped in cluster 1 and 2, c) seedling roots grouped in cluster 3–4; d) seedling roots grouped in clusters 5 and 6. Scale bars: 500 μm.</p

Mitochondrial morphology and distribution in mature and senescent leaves of grapevine plants grown in vitro, expressing β-GFP.

<p>(A) Bi-dimensional GFP-fluorescence image resulted from a projection of laser scanning confocal image sequences, showing long branched structures formed by mitochondria in a mature leaf. (B) Bi-dimensional projection image of senescent leaf in S2 senescence stage showing enlarged, round shape mitochondria (see arrows). Scale bar  = 48 µm.</p

Assayed PGP traits of selected strain, their cluster attribution and their taxonomical identification.

<p>Assayed PGP traits of selected strain, their cluster attribution and their taxonomical identification.</p

Visualization by confocal laser microscopy of mitochondria in leaves of grapevine plants, expressing β-GFP during senescence.

<p>Confocal analyses in mesophyll (A) and stomata (B) cells at different senescence phases: M (mature green leaf), S1, S2 and S3 (senescent leaves). Scale bar  = 10 µm. The number and volume of mitochondria were quantified in mesophyll (C, E) and stomata (D, F) leaf cells at different senescence stages. Asterisks indicate values that are statistically different from those of M stage by Student's <i>t</i> test (** <i>P</i><0.01; * <i>P</i><0.05), performed on 10 replicates.</p

Effects of bacterial strains on <i>Arabidopsis</i> root architecture.

<p>a-c) supervised model based clustering performed on the variables a) length b) diameter and c) area of the roots. d) <i>Arabidopsis</i> plantlet phenotypes (after two weeks of growing) grouped in different clusters obtained from “model based cluster” analysis in comparison with non-inoculated (control) and 50nM IAA-treated seedlings. Scale bars: 1 cm.</p

Percentage of strains, for each of the six clusters of recorded plant root response types, that display the tested PGP traits.

<p>Percentage of strains, for each of the six clusters of recorded plant root response types, that display the tested PGP traits.</p