Living near water: Ecological observations on the Ecuador Sipo, Chironius grandisquamis, (Peters 1869) (Serpentes: Colubridae), in the Middle Magdalena River Valley, Colombia

More than 40 species of snakes inhabit the humid forests of the Middle Magdalena River Basin of Colombia, yet studies on the basic aspects of snake ecology and natural history in this region are scarce. We searched for Ecuador Sipos (Chironius grandisquamis) during six years (2014–2019) of 6–24-day visual-encounter surveys by day and night in both rainy and dry periods. In 2,967 person-hours, we recorded 16 individuals, half during rainy and half during dry periods. Fourteen of the 16 encounters were in the evening and two in the morning. Snakes recorded during the day were foraging on the ground, whereas those recorded at night were inactive and perched in vegetation. Most inactive individuals had selected perches along streams flanked by riparian forests; ten were in shrubs and four in trees on branches 120–600 cm above the ground. We also record predation on a northern rainfrog (Craugastor metriosistus) on the forest floor during the day.

Ant Rafting in an Extreme Ecosystem

Ants are among the most abundant organisms on Earth, being adapted for living on different solid surfaces. However, in some habitats, like riparian forests and flooded plains, water can be a constant obstacle, and overcoming this obstacle can be essential to determine the persistence of ants in such habitats. While most ant species avoid the water during a flood by foraging at higher elevations or climbing on trees, a few species developed ways to overcome this obstacle by swimming. Here, we report, for the first time, ants of the species Linepthema micans (Forel 1908) performing rafts. We observed 14 rafts in three consecutive days at approximately 1400 meters a.s.l. in Serra do Cipó, Brazil. Notably, this is the first record of ant rafting in tropical mountaintop grasslands, which are extreme habitats with shallow and sandy soils, and where small temporary water pools are extremely common in the wet season.

A new and endangered species of Justicia L. (Justicieae-Acanthaceae) from the riparian forests of northern Goiás State, Brazil

Justicia pusilla, a new species of Acanthaceae from Brazil, is described and illustrated. The new species is one of the smallest plants in the genus. It is morphologically allied with Justicia laevilinguis and “Justicia indespecta”, but differs from both by a set of characters related to habit, leaves, spikes, bracts, bracteoles, calyx, corolla and seeds. It is considered endangered due to its restricted geographic distribution and low population density.

Diurnal and Seasonal Variations of Particulate Matter Concentrations in the Urban Forests of Saetgang Ecological Park in Seoul, Korea

Urban forests provide various ecosystem services. Although the function of reducing particulate matter (PM) in the city is known, research into the reduction of PM according to the type and structure of various forests is still needed. It is essential to study the characteristics of PM concentration in urban riparian forests, which are frequently used for outdoor walks in the COVID-19 era. In this study, the diurnal and seasonal changes in PM10 and PM2.5 concentrations were analyzed in urban forests with different structures in the riparian forests located in central Seoul. The PM concentration was found to be high regardless of the time of the day in forests with a developed canopy layer. Similar results were found before and after leaf emergence compared with the seasonal PM concentration. The results of this study highlight the need for planned and periodic management of the canopy layer and underground vegetation to prevent the PM trapping effect to ensure the safe use of riparian forests in cities.

Comparing environmental impacts of alien plants, insects and pathogens in protected riparian forests

The prioritization of alien species according to the magnitude of their environmental impacts has become increasingly important for the management of invasive alien species. In this study, we applied the Environmental Impact Classification of Alien Taxa (EICAT) to classify alien taxa from three different taxonomic groups to facilitate the prioritisation of management actions for the threatened riparian forests of the Mura-Drava-Danube Biosphere Reserve, South East Europe. With local experts we collated a list of 198 alien species (115 plants, 45 insects, and 38 fungi) with populations reported in southeast European forest ecosystems and included them in the EICAT. We found impact reports for 114 species. Eleven of these species caused local extinctions of a native species, 35 led to a population decrease, 51 to a reduction in performance in at least one native species and for 17 alien species no effects on individual fitness of native species were detected. Fungi had significantly highest impact and were more likely to have information on their impacts reported. Competition and parasitism were the most important impact mechanisms of alien species. This study is, to our knowledge, the first application of EICAT to all known alien species of several taxonomic groups in a protected area. The impact rankings enabled to identify taxa that generally cause high impacts and to prioritize species for the management in protected areas according to their impact magnitudes. By following a standardized impact protocol, we identified several alien species causing high impacts that do not appear on any expert-based risk list, which are relevant for policymakers. Thus, we recommend that alien species be systematically screened to identify knowledge gaps and prioritize their management with respect to spatio-temporal trends in impact magnitudes.

Landscape and tree community effects on the infestation of an endemic fungal pathogen in riparian forests were mediated by leaf traits

Background Plant pathogens are regarded as crucial agents shaping the dynamics of natural forest communities. Marssonina leaf spot of poplar is induced by an endemic pathogenic fungus Drepanopeziza populi, causing increased damage to riparian poplar stands in recent years. However, such endemic fungal diseases have received little attention at the landscape scale, despite the key role of landscape heterogeneity in the development and spread of emerging forest diseases. Moreover, most studies have insufficiently captured multiple ecological factors driving the infestation of an endemic pathogen acting at the landscape, community, and individual scales. Methods We measured pathogen load, disease prevalence, and disease severity of Marssonina leaf spot in poplars in riparian forests. We explored the direct and indirect effects of multiple ecological factors on pathogen infestation using a path analysis. Specifically, we first assessed the effects of landscape and community factors on leaf traits including leaf area, specific leaf area (SLA) and leaf dry matter content (LDMC), and then examined the role of these factors in shaping disease dynamics. Results Path analysis showed that landscape features had no direct impact on leaf traits and pathogen infestation, but directly affected tree community composition. Landscapes with higher forest cover resulted in higher host density and tree diversity. Host density was the most important factor of pathogen load, with higher host density resulting in more symptomatic leaves. Tree diversity had direct effects on disease prevalence, with poplars growing in mixed forest stands far less affected by pathogens than in pure stands. Moreover, disease prevalence was positively related to pathogen load. Tree diversity strongly reduced SLA, but increased LDMC. Higher SLA was found to increase pathogen load and disease severity, but higher LDMC was found to reduce both of them. Conclusions Our results show that the effects of landscape and tree community on Marssonina leaf spot disease are mediated by leaf traits. Disentangling the effects of biotic and abiotic factors affecting pathogen infestation contributes to reduce the overall impact of this disease, which can provide policy makers with sustainable management of endemic plant diseases in natural forests.

Comparing Soil Nitrous Oxide and Methane Fluxes From Oil Palm Plantations and Adjacent Riparian Forests in Malaysian Borneo

Riparian forests are often kept as buffers between rivers and oil palm plantations. Many benefits of riparian forests, such as increasing biodiversity and providing a travel corridor for wildlife have been documented. Conversely, data on fluxes of the greenhouse gases nitrous oxide (N2O) and methane (CH4) from riparian forests are sparse. Nitrogen (N) from fertilizer applied in the oil palm plantations leached to the adjacent riparian forests, may increase emissions of N2O. Methane (CH4) fluxes might also differ between oil palm plantations and riparian forests due to carbon (C) availability. In this scoping study, we installed transects from three mature oil palm plantations to adjacent riparian forests within the SAFE project landscape in Sabah, Malaysia (https://www.safeproject.net) for measurements of greenhouse gases and associated parameters every 2 months for 13 months. Emissions of N2O were higher from riparian forests with 40.4 [95% confidence intervals (CI): 35.7–44.6] μg N2O-N m–2 h–1 than from an equivalent area of oil palm plantation 27.6 (CI: 23.1–32.3) μg N2O-N m–2 h–1. Methane uptake was significantly higher from the riparian forest with −14.7 (CI: −21.1 to −8.3) μg CH4-C m–2 h–1 compared to slight positive emission in the oil palm plantations of 6.3 (CI: 1.1–11.4) μg CH4-C m–2 h–1. We are contributing urgently needed flux data for less well studied riparian forests in the Tropics, however, additional long-term studies are needed to be able to draw wider conclusions than possible from this scoping study alone.