Grasslands And Forests In Nebraska Are Vulnerable To Tree Invasion From Roadsides

Roadsides can be vectors for tree invasion within grasslands by bisecting landscapes and facilitating propagule spread to interior habitat. Current invasive tree management in North America’s Great Plains focuses on reducing on-site (i.e., interior habitat) vulnerability through on-site prevention and eradication, but invasive tree management of surrounding areas known to serve as invasion vectors, such as roadsides and public rights-of-ways, is sporadic. We surveyed roadsides for invasive tree propagule sources in a southeastern Nebraska grassland landscape to determine how much of the surrounding landscape is potentially vulnerable to roadside invasion, and by which species, and thereby, provide insights into the locations and forms of future landcover change. Invasive tree species were widespread in roadsides. Given modest seed dispersal distances of 100-200 m, our results show that roadsides have potential to serve as major sources of grassland exposure to tree invasion, compromising up to 44% of grasslands in the Denton Hills. Under these dispersal distances, funds spent removing trees on grassland properties may have little impact on the landscape’s overall vulnerability, due to exposure driven by roadside propagule sources. A key implication from this study is that roadsides, while often neglected from management, represent an important component of integrated management strategies for reducing grassland vulnerability to tree invasion.

Innovative Model of the Cost Price Calculation of Products from Invasive Non-Native Wood Species Based on the FTDABC Method

Invasive tree species continue to spread, so in addition to strategies to limit this their use in the production of innovative products must be considered. This research aimed to develop and apply a model for calculating the cost price of invasive wood products considering the specificities of materials and production process, and is suitable for quickly assessing the economic feasibility of using the selected tree species for a given product. The TDABC method with the inclusion of fuzzy logic was used to incorporate the uncertainty of time and quality parameters. In the model, the imprecise values of these parameters are represented with triangular fuzzy numbers. Using a furniture product (dining table) made of black locust wood as an example, we demonstrated the applicability of the developed model. We found that the most probable cost price of a table made of black locust wood is comparable to the price of a product made of oak wood. In this way, we proved the potentially high economic value of invasive wood. The innovative products from invasive non-native wood species can achieve a high added value due to their visual characteristics and attractive appearance. Such use could increase interest in the (more efficient) management of invasive tree species, which would help to manage and use them efficiently. For further research, it would be useful to apply the proposed model to other invasive tree species as well as to other products.

Effects of the Invasive Tree Species Ailanthus altissima on the Floral Diversity and Soil Properties in the Pannonian Region

Tree-of-heaven (Ailanthus altissima) is one of the most dangerous and widespread invasive woody plant species in Europe. Despite the fact that A. altissima is in the focus of an increasing number of research projects, the impact of its mass spread on native vegetation, its diversity, and changes in soil quality are still incomplete. The current study addresses the effects of this invasive species on plant diversity and soil parameters simultaneously. The main objective of our research is to determine the impact of cover and mass of A. altissima on the diversity of each forest layer; the examined soil parameters and on other selected environmental variables. For botanical and pedological investigations we selected nine A. altissima-dominated sites in Central Europe, in the Pannonian Biogeographical Region. Based on our results, it can be stated that fully grown A. altissima-dominated stands can displace other taxa by their shading and allelopathy, thereby reducing canopy layer diversity. The increase in the species richness of the shrub layer had a positive correlation with the diversity of the floor layer and also with the humus and ammonia content of the soil. As the diversity of shrub layer and floor layer positively correlated with many soil parameters, the diverse vegetation of these layers can represent a potential opportunity for the regeneration of areas infected with A. altissima.

Invasion of Celtis tala forests by Ligustrum lucidum in Argentina: impact on soil properties and the arbuscular mycorrhizal community

The arrival of invasive plants can cause drastic changes to ecosystems, such as the displacement of native plant communities and the disruption of ecological functions. <i>Ligustrum lucidum</i> is an invasive tree species that has been registered in numerous regions worldwide. We analysed the effect of the expansion of <i>L. lucidum</i> on the edaphic properties and mycorrhizal fungal communities in forests of <i>Celtis tala</i> located in central-western Argentina. Sampling sites were established along a gradient of invasion, in which we measured the forest structure and soil physical-chemical factors and identified the fungal species using morphological techniques. The analysis of the variance revealed severe changes in the tree structure and a decrease in the concentrations of organic matter and nitrogen in the invaded sites. Thirty-two Glomeromycota species were identified, belonging to 6 families. The abundance of <i>Dentiscutata cerradensis</i> decreased with the invasion, whereas <i>Funneliformis mosseae</i> and <i>Septoglomus constrictum</i> increased. The alpha diversity of the arbuscular mycorrhizal communities showed no differences between sites. The beta diversity decreased at invaded sites, indicating a tendency towards convergence and reduced variability in these communities in the presence of the exotic species.

Ecosystem Changes in Shola Forest-Grassland Mosaic of the Nilgiri Biosphere Reserve (NBR)

The Shola grasslands are tropical montane forests found in the high altitudes of Western Ghats separated by rolling grasslands. These unique ecosystems act as the home for many of the floral and faunal endemic species and also serve as the water reservoir for the Nilgiri Biosphere Reserve. The grassland let the rainwater to flow through the sholas into the stream and provide water to the region throughout the year. The region once covered with tropical montane forest and grassland was transformed into a land of plantation over the centuries. As the grasslands are easy to clear off, tea estates, coffee estates and timber plantations were established by the British and later by the Indian forest department to satisfy the various need of the growing economy. Majority of this region are being replaced by the invasive tree species and agricultural plantations. This led to the loss of major proportion of the shola forest and grassland. Many developmental works have been carried out in the region and these developmental activities results in the gradual disappearance of the ecosystem. These ecosystem need to be conserved and hence, identifying the knowledge gap and application of current state of knowledge is necessary.

Dendroflora of the Nataliivskyi Park (Kharkiv region, Ukraine): taxonomic diversity and monitoring of plantations

To develop measures for the restoration of historic plantations and landscapes of the Nataliivskyi Park (Kharkiv region, Ukraine), the investigations of taxonomic composition and distribution of woody plant taxa, as well as structure of different landscape areas, were carried out in 2018–2019. The recent studies were realized according to the same protocol applied in 1997 by Y. Klymenko, and taking into account previously published data.In 1939, the dendroflora of the Nataliivskyi Park comprised about 100 taxa. Later, the number of taxa significantly decreased, and in 1950 the park’s dendroflora comprised only about 40 taxa. In 1997 there were 74 taxa reported. Since 1997, the taxonomic composition of the park’s dendroflora has been enriched by ten taxa and is currently represented by 84 taxa. Simultaneously, the number of valuable plants in the plantations decreased (only one or two plants represent some such taxa). Due to a bark beetle attack on drought-weakened trees of Picea abies and P. pungens, most of them withered. The area of allotments with Pinus sylvestris and Quercus robur remained almost the same, which indicates their stability. The area of allotments with the domination of such naturalized introducers as Acer negundo and Robinia pseudoacacia and the area of allotments with the domination of neither taxa have increased. In the landscapes, the redistribution of the types of areas appeared. The forest type of landscape became predominant, while the meadow type of landscape has almost disappeared.Hence, to restore historical plantings and landscapes, it is necessary to re-cultivate taxa represented here during the park’s heyday and remove invasive tree species. Although cuttings in protected areas are currently prohibited, our investigations showed that they might help preserve such valuable territories as Nataliivskyi Park.