Connectivity, landscape structure, and plant diversity across agricultural landscapes: novel insight into effective ecological network planning

Modelling enhancement of Ecosystem Services provision through integrated agri-environment and forestry measures

Agri-environment and forest schemes can support landowners to conserve and enhance agricultural and forest ecosystems. The effectiveness of these schemes is often debated due to discrepancies that occur between the application of such measures and the delivery of Ecosystem Services (ES). We simulated the application of a suite of farmland and forest measures within a range of biophysical contexts in known High Nature Value landscapes across the Republic of Ireland. Three high resolution geospatial scenarios simulated the anticipated effects of the measures: i) a Baseline Scenario of current conditions, ii) an Enhanced Scenario simulated the application of measures, and iii) using the new 'Restoration Planner' freeware, an Enhanced + Connectivity Scenario simulated the application of additional targeted measures for ecosystem connectivity. Across all scenarios, we modelled and compared the responses of a range of ES including: habitat quality, carbon storage, production income and ecosystem connectivity. Multivariate analyses were used to ordinate and determine eight bundles of measures and their associated effect on ES and connectivity. These bundles were subsequently contextualised by examining unique landscape characteristics in which they occurred. The results show that measures applied under the Enhanced Scenario resulted in weak gains to carbon storage (2 %), strong gains to habitat quality (28 %), and weak losses to production income (-7 %) and ecosystem connectivity (-2 %). Similarities were observed under the Enhanced + Connectivity Scenario, though with comparably stronger gains to ecosystem connectivity (15 %). This study is the first to demonstrate the potential synergies and trade-offs to ES that can result from the integrated and targeted application of both farmland and forest measures within a variety of landscape characteristics.

Driving effects of land use and landscape pattern on different spontaneous plant life forms along urban river corridors in a fast-growing city

River corridors are critical in connecting fragmented greenspace and providing habitats for plants and animals. There is a paucity of information on the detailed influence of land use and landscape patterns on the richness and diversity of distinct life forms of urban spontaneous vegetation. This study aimed to identify the variables that dramatically affect spontaneous plants and then disentangle how to manage such a variety of land types to maximize the biodiversity-supporting function of urban river corridors. The total species richness was remarkably influenced by the amount of commercial, industrial, and waterbody area and the landscape complexity of water, green space, and unused land. In addition, the spontaneous plant assemblages of different life forms significantly differed in their responses to land use and landscape variables. Vines were more sensitive to urban sites, i.e., strongly negatively affected by residential and commercial areas but positively supported by green space and cropland. Multivariate regression trees indicated that the total plant assemblages were clustered most remarkably by the total industrial area, and the classified responding variables differed among distinct life forms. The colonizing habitat of spontaneous plants explained a high proportion of the variance and was also closely related to the surrounding land use and landscape pattern. These scale-specific interaction effects ultimately determined the variation in richness among various spontaneous plant assemblages in urban sites. Based on these results, in future city river planning and design, spontaneous vegetation could be protected and promoted by a nature-based solution according to their adaptability and preference for distinct landscape characteristics and habitat features.

Land-use diversity can better predict urban spontaneous plant richness than impervious surface coverage at finer spatial scales

Urban spontaneous plants, that are not intentionally propagated by humans and do not belong to the remnants of the natural habitats, not only occur in green spaces but are also distributed in diverse microhabitats in impervious surface areas. Impervious surface coverage is commonly used in studies on spontaneous plant diversity patterns in human-dominated landscapes; however, the role of habitat diversity (i.e., land-use diversity) has been overlooked. Here, we surveyed spontaneous plant composition and land uses (12 types) in 321 0.25 ha sampling sites on the Chongming District islands, Shanghai, to determine the role of land-use diversity in explaining species richness. We examined the linear relationships between species richness and land-use diversity, and quantified the importance of impervious surface coverage and land-use diversity using the random forest (RF) method. All these analyses were conducted for spatial scales from 0.25 to 5 ha in 0.25 ha increments. We found an overall positive relationship between species richness and land-use diversity, and the RF model predicted approximately 50% of the species richness variation at the smallest spatial scale. However, the positive relationship weakened with spatial scale increase, and a rapid decline in explanatory power occurred for all predictor variables in the RF model. Besides impervious surface coverage, both the vegetated and non-vegetated land-use diversity contributed substantially to the prediction of species richness at finer spatial scales. The findings clarify how land-use diversity, both in green spaces and impervious surface areas, affect urban spontaneous plant richness and should be considered in urban biodiversity conservation strategies at the neighborhood scale.

Features of Plant Community and Driving Forces of Plant Community Succession in the Typical Desert Wetlands

Desert wetlands play a significant role in flood regulation, water purification, biodiversity maintenance, and regional ecological environment improvement. Vegetation is a key factor affecting wetland function and it is important to study the features of plant community and the driving forces of plant community succession. The Ningxia Habahu National Nature Reserve, a typical desert wetland ecosystem, was selected to study the features of wetland plant communities including plant density, biomass and frequency, and vegetation coverage, as well as the habitats, structural characteristics, species composition, dominant population structure, and other characteristics of different ecosystems. Data was collected using long-term fixed-point observation, sampling monitoring, and other methods. The results showed that the total plant density, total biomass, Magalef index and Shannon–Wiener index of the different desert wetlands in the reserve area were all relatively low, which was caused by the poor habitat and salinization of the arid environment. There was no significant difference between the root–shoot ratio of the wetland plants in the reserve area and that of the construct species of other ecosystems. The specific leaf area of the wetland plants was also not significantly different from that of the construct species of other ecosystems. Vegetation nitrogen-to-phosphorus (N/P) ratios were found to be the key driving force for the succession of plant community in the desert wetlands. These results not only provide underlying insights for the improvement of species diversity and ecological environment, but also provide a scientific basis for the sustainable protection and restoration of typical desert wetlands.