Tree plantations are hot-spots of plant invasion in a landscape with heterogeneous land-use

Abstract

Invasion of alien plant species is one of the main reasons for biodiversity loss in terrestrial ecosystems. However, alien plant species are not evenly distributed in the landscape. We studied which factors determine the actual level of neophyte invasion in a landscape with heterogeneous land-use and which habitats are the most infected. Since neophyte species with different life-forms can respond differently to the factors determining the invasion, species groups of annual, herbaceous perennial and woody neophytes were also analyzed separately. The study was conducted within the field site network of the Kiskun-LTER program (Hungary), in 16 sites of 5 km  5 km. Fifteen habitat types were distinguished belonging to five major land-use/land cover types (agricultural land, abandoned agricultural land, tree plantation, semi-natural grassland and semi-natural forest). Present and past land-use, landscape composition and environmental variables were included as factors with a potential impact on the level of invasion. The most important factor determining invasion level was present habitat type, followed by the past habitat type of the location and landscape context. Tree plantations, agricultural habitats and recently abandoned agricultural habitats had the highest level of invasion. As expected, annual neophytes were most abundant in agricultural habitats, while perennial herbaceous neophytes were most abundant in old-fields and plantations, and woody neophytes in tree plantations. Past agricultural land-use was reflected in the higher levels of invasion of annuals and perennials, and past forestry practice resulted in higher levels of invasion of woody neophytes. In a landscape with a higher proportion of tree plantations, not only the tree plantations, but primary woodland [ 2 4 0 _ T D $ D I F F ] patches also showed higher levels of invasion by woody neophyte species. Our results indicate the importance of present and past land-use in plant invasion and suggest that tree plantations are hot-spots of plant invasion and threaten the remnants of semi-natural vegetation.

Habitat heterogeneity as a key to high conservation value in forest-grassland mosaics

“…Our results show that the grassland habitat had the highest naturalness. In addition, adventive tree seedlings were completely absent from grasslands, which is in good agreement with earlier studies that indicated low invasibility of undisturbed sand grasslands in the region (Bagi, 2008;Csecserits et al, 2016;Szigetvári, 2002). The conservation importance of the grassland habitat is probably further enhanced by other taxa that were not analysed in this study.…”

“…In addition, large and medium forest patches hosted the largest proportions of adventive trees; thus, these forests should be regarded as potential invasion hot-spots. Csecserits et al (2016) identified the following habitats as invasion hot-spots in our study region: tree plantations, agricultural habitats, oldfields, and oak forests. Pándi et al (2014) concluded that abandoned farms are invasion centres.…”

Three years of vegetation development worth 30 years of secondary succession in urban‐industrial grassland restoration

“…These results suggest that seeding successfully accelerated succession towards secondary grasslands and primary closed grasslands in three years, compared to secondary reference grasslands developed over more than 30 years. Several investigations (Albert et al., ; Csecserits & Rédei, ; Csecserits et al., ; Halassy, ; Molnár & Botta‐Dukát, ; Ruprecht, ) found that spontaneous succession at old fields in the Pannonian region can develop to semi‐natural grasslands on disturbed areas within 10–20 years; however, the cover of specialist species remains low (Molnár & Botta‐Dukát, ; Prach et al., ) and the cover of alien species is much higher than in natural grasslands (Csecserits et al., ,). Mitchley, Jongepierová, and Fajmon () consider 10–60 years insufficient to restore species‐rich grasslands.…”

Invasive Asclepias syriaca can have facilitative effects on native grass establishment in a water‐stressed ecosystem

“…The main land cover types of the region are agricultural fields, forest plantations, semi‐natural habitats and ex‐arable lands (Csecserits et al., ). Land abandonment has been occurring in agricultural fields, with the lowest productivity due to socio‐economic changes and a decrease in the regional groundwater table level since the 1960s (Biró, Révész, Molnár, Horváth, & Czúcz, ; Csecserits & Rédei, ).…”