Understanding the Environmental Background of an Invasive Plant Species (Asclepias syriaca) for the Future: An Application of LUCAS Field Photographs and Machine Learning Algorithm Methods

Abstract

For developing global strategies against the dramatic spread of invasive species, we need to identify the geographical, environmental, and socioeconomic factors determining the spatial distribution of invasive species. In our study, we investigated these factors influencing the occurrences of common milkweed (Asclepias syriaca L.), an invasive plant species that is of great concern to the European Union (EU). In a Hungarian study area, we used country-scale soil and climate databases, as well as an EU-scale land cover databases (CORINE) for the analyses. For the abundance data of A. syriaca, we applied the field survey photos from the Land Use and Coverage Area Frame Survey (LUCAS) Land Cover database for the European Union. With machine learning algorithm methods, we quantified the relative weight of the environmental variables on the abundance of common milkweed. According to our findings, soil texture and soil type (sandy soils) were the most important variables determining the occurrence of this species. We could exactly identify the actual land cover types and the recent land cover changes that have a significant role in the occurrence the common milkweed in Europe. We could also show the role of climatic conditions of the study area in the occurrence of this species, and we could prepare the potential distribution map of common milkweed for the study area.

Survival and regeneration ability of clonal common milkweed (Asclepias syriaca L.) after a single herbicide treatment in natural open sand grasslands

“…The 2000-ha study area has been protected from grazing since 1974. In the last quarter century, the site has been invaded by common milkweed whose extended stands can be found throughout the protected area [20,68,72,73]. It prefers mostly less heavy soils (well drained sandy or sandy-loess soils).…”

“…The clonal structure of A. syriaca comprises solitary or few (2-5) groups of shoots that develop vegetatively by buds of plagiotropic rhizomatic roots [68]. Milkweed is one of the most dangerous invasive transformer species currently widespread in Hungary and is spreading in Czech Republic, Romania, Poland, Serbia, and several other countries [66,68,[70][71][72]. It primarily endangers psammophilous habitats where its structure differs from that of natural vegetation [73].…”

Survival and regeneration ability of clonal common milkweed (Asclepias syriaca L.) after a single herbicide treatment in natural open sand grasslands

“…The 2000-ha study area has been protected from grazing since 1974. In the last quarter-century, the site has been invaded by common milkweed whose extended stands can be found throughout the protected area 20,69,72,73 . In 2011, an isolated milkweed stand embedded in natural psammophilous vegetation units was mapped (GPS coordinates: N46° 53.488′ E019° 24.771′).…”

“…Common milkweed Asclepias syriaca is one of the most dangerous invasive transformer species currently widespread in Hungary and is spreading in Czech Republic, Romania, Poland, Serbia, and several other countries 68 – 72 . It primarily endangers psammophilous habitats where its structure differs from that of natural vegetation 73 .…”

Elaborating Hungarian Segment of the Global Map of Salt-Affected Soils (GSSmap): National Contribution to an International Initiative

“…Digital soil mapping (DSM), which has become a successful sub-discipline of soil science with an active research output [10], aims to provide spatial soil information for a wide range of studies, such as precision agriculture [11,12], hydrology [13][14][15], environmental sciences [16,17], conservation biology [18,19] or spatial planning [20,21]. For this purpose, geostatistical techniques are widely used, which have been complemented by machine learning algorithms in the past decade.…”