Search

Background Morphological leaf traits are frequently used to quantify, understand and predict plant and vegetation functional diversity and ecology, including environmental and climate change responses. Although morphological leaf traits are easy to measure, their coverage for characterising variation within species and across temporal scales is limited. At the same time, there are about 3100 herbaria worldwide, containing approximately 390 million plant specimens dating from the 16th to 21st century, which can potentially be used to extract morphological leaf traits. Globally, plant specimens are rapidly being digitised and images are made openly available via various biodiversity data platforms, such as iDigBio and GBIF. Based on a pilot study to identify the availability and appropriateness of herbarium specimen images for comprehensive trait data extraction, we developed a spatio-temporal dataset on intraspecific trait variability containing 128,036 morphological leaf trait measurements for seven selected species. [ABSTRACT FROM AUTHOR]

Previously it was shown that formation of parenchyma tissue inclusions in the wood of Karelian birch (Betula pendula Roth var. carelica) was associated with the high activity of apoplastic invertase. In our experiments with injection of sucrose solutions (1.0%, 2.5%. 5.0%, 10%) into the cambial zone of silver birch (B. pendula var. pendula) the activity of apoplastic invertase in the zone of experimental treatment also rose. Activity of that enzyme gradually increased with the rise of concentration of sucrose solution from 1% to 5% and sharply increased in the variant with 10% of sucrose. Sucrose concentration in tissues coincided with the enzyme activity: its level rose with the increase in sucrose concentration from 1% to 5% and sharply decreased in the variant with 10% of sucrose. At this concentration of exogenous sucrose the growth in parenchyma volume was observed: in the phloem the proportion of parenchyma cells significantly increased, in the xylem thick parenchyma layer was formed. Similar experiments performed on the trunks of alder (Alnus incana (L.) Moench) and aspen (Populus tremula L.) have shown that reaction of that tree species differed from the birch reply. In alder tissues no signs of structural or functional changes were detected. In aspen tissues the percentage of structural elements in conducting tissues remained the same but their functional state changed as evidenced by the increase in the proportion of parenchyma cells with large vacuole. Sucrose in tissues of aspen and alder in the experiment was mostly absent. Glucose was represented in minor amounts, fructose levels were significantly higher. The data indicate the ability of alder and aspen tissues to utilize large amounts of sucrose, not allowing its accumulation in the trunk tissues. This may be the possible reason for the absence of structural deviations in phloem and xylem of these species in the variants with the high concentration of sucrose. The causes of quick sucrose utilization in aspen and alder would be the subject of further investigations.

Data from four soil profiles studied through pollen and macroscopic charcoal analyses were used to identify specific palynological assemblages associated with a traditional land-use system documented in the Eastern Ligurian Apennines (NW Italy) between the 18th and early 20th century, concerning a cyclical use of grey alder plots for temporary cultivations involving to the use of controlled fire. This is the first attempt to verify on palynological evidence some hypotheses raised by previous historical ecology studies about the consequences of this agricultural practice (recently named alnocoltura) on past and present vegetation. Our investigations underline (1) high percentages of anthropogenic pollen indicators, (2) increase of Ericaceae percentages, (3) low pollen percentages of Alnus, (4) high macrocharcoal concentrations and (5) high values of palynological richness during periods affected by the alnocoltura cycle according to the historical sources. Similar patterns are also detectable in pollen diagrams from two adjacent peat bogs. The paper shows the strength of an interdisciplinary methodology (field observations, cartographical and archival historical data, palynological and archaeological investigations) for studies of past land-use systems. By demonstrating the necessity of a long-term prospective in environmental reconstructions for the preservation of the cultural landscape, one of the important elements of this research is its potential contribution to issues of habitat management and nature-conservation policy. Further analyses are needed to test the replicability and reliability of the hypotheses derived from this study. [ABSTRACT FROM AUTHOR]

Copyright of Natura Croatica is the property of Natura Croatica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biomass analyses were conducted to evaluate the growth performance of an Alnus incana (L.) Moench stand established for the restoration of a land slide site. The study aimed to pioneer the quantification of biomass accumulation of alders which were planted for soil bioengineering and stabilisation purposes under extreme soil conditions. For above-ground phytomass estimation, allometric functions on a tree component level were created using linear regression analyses after ln-transformation. Based on D130-D10-relations D10-data were applied for function derivation. Best fits were computed using ln-transformed D10 and height data. At 7,023 stems ha−1 (all trees >20 cm height), the total stand biomass added up to 18,000 kg ha−1, had an LAI of 1.5 and indicated a high productivity even under unfavourable soil conditions. In the light of the results, grey alders appear to be highly valuable for growing on slide prone sites, indicating that they also exert a positive influence on the soil water regime and thus on slope stability. [ABSTRACT FROM AUTHOR]