Long-Term Changes of Softwood Floodplain Forests—Did the Disappearance of Wet Vegetation Accelerate the Invasion Process?
Open Access
- 19 November 2020
- Vol. 11 (11), 1218
- https://doi.org/10.3390/f11111218
Abstract
Objectives: We followed the long-term changes of softwood floodplain forests strongly altered by water regime changes and examine the behaviour of neophytes in this environment. Here we ask: (1) How did the composition of neophyte and native species change? (2) How did the presence of species that prefer wetter conditions change? (3) What traditionally distinguished type of softwood floodplain forests (a wetter one or a more mesophilous one) do neophytes prefer? (4) What environmental factors affect the native species richness and the occurrence and cover of neophytes? Materials and Methods: Historical and recent phytosociological relevés of the association Salicetum albae of the Slovak part of the inland delta of the Danube River were used (177 plots together). For each plot, the number and cover of neophytes and number of native species were measured, and the Shannon-Wiener diversity index, the stand structure (cover of tree, shrub and herb layer) and the mean of Ellenberg indicator values were calculated and compared among time periods. Temporal trends of the soil moisture characterized by indicator values calculated for each plot were determined using a Linear Model. The synoptic table of traditional vegetation types was done to show preferences of neophytes for particular softwood forest types. The effect of site conditions on native species richness and occurrence of neophytes was determined using the Generalized Linear Model. Results: The relative number and cover of neophyte species increased and the absolute number of native species decreased over time; the vegetation of the area has changed from variable hygrophilous and mesophilous to homogenised mesophilous; most non-native species prefer the mesophilous vegetation of the floodplain forests; the wetter parts of the floodplain more successfully resisted invasions. Conclusions: The vegetation of the researched area has considerably changed over time to become less diverse and less hygrophilous, and has more invasive species. To preserve floodplain forests, natural hydrological and connectivity patterns should be adequately protected.Keywords
This publication has 40 references indexed in Scilit:
- Flow regulation reduces native plant cover and facilitates exotic invasion in riparian wetlandsJournal of Applied Ecology, 2011
- The role of rivers and streams in the migration of alien plants into the Polish CarpathiansBiodiversity Research and Conservation, 2011
- Invasive Species, Environmental Change and Management, and HealthAnnual Review of Environment and Resources, 2010
- Is phylogenetic relatedness to native species important for the establishment of reptiles introduced to California and Florida?Diversity and Distributions, 2010
- Contrasting patterns in the invasions of European terrestrial and freshwater habitats by alien plants, insects and vertebratesGlobal Ecology and Biogeography, 2010
- Simulated recruitment of riparian trees and shrubs under natural and regulated flow regimes on the Wisconsin River, USARiver Research and Applications, 2006
- DELAYED EFFECTS OF FLOOD CONTROL ON A FLOOD‐DEPENDENT RIPARIAN FORESTEcological Applications, 2005
- TURBOVEG, a comprehensive data base management system for vegetation dataJournal of Vegetation Science, 2001
- Fluctuating resources in plant communities: a general theory of invasibilityJournal of Ecology, 2000
- Naturalization and invasion of alien plants: concepts and definitionsDiversity and Distributions, 2000