Impact of Various Types of Polluted Water, Rhizome Size and Water Depth on Sprouting of Common Cattail (Typha latifolia L.) Rhizomes

Three different studies were carried out in the Department of Weed Science, The University of Agriculture Peshawar, in January 2016 to examine the impacts of polluted water from various sources, water depths and rhizome size on the resprouting ability and establishment of common cattail rhizomes fragments after mechanical control. These experiments were arranged in Completely Randomized Design (CRD), replicated thrice. The selected experimental units were pots 20 inches wide and 12 inches deep. Typha latifolia L. rhizomes were placed in each pots and covered with a little silt to avoid it’s direct contact and desiccation from sunlight. The impacts of water quality on T. latifolia rhizomes sprouting were significant. Lowest ratio of sprouted and un-sprouted buds (50.00 % each), 1st sprout length (37.33 and 40 cm), average sprout length (17.47 and 16.96 cm), average biomass (9.99 and 10.27 g) and growth rate (0.172 and 0.196 g/day) were noted for saline water and industrial acidic effluents, respectively. However, highest rhizome sprouting was recorded for tap water applied as check followed by industrial effluent alkaline. The data regarding the impact of water depth on T. latifolia rhizome sprouting showed that sprouting (44.44 %), 1st sprout length (43.33 cm), average sprout length (20.99 cm), average sprout biomass (7.84 g), average diameter of the newly formed rhizome (0.24 cm) and growth rate (0.4233 g/day) were recorded for rhizomes placed at zero level water depth, while maximum buds sprouted at 4 inches water depth. Similarly, impact of rhizome size on resprouting revealed that minimum bud sprouting (44.44%), 1st sprout length (44.86 cm), average sprout length (0.93 cm) and biomass of newly formed rhizome (4.97 g) and minimum days to emergence (9) were noted for smaller rhizome length (2 buds) compared to longer rhizomes with 10 buds. Therefore, on the basis of our findings, saline and industrial effluent acidic, no standing water (zero water surface level) and shorter rhizome size resulted in least bud sprouting and minimized the chance of further infestation in an eco-friendly and ecological way without the use of herbicides. Whereas alkaline industrial effluents, standing water up to 4 inches and longer rhizome fragments enhanced sprouting and re-establishment of the T. latifolia and these strategies can be utilized where the aim is to grow and establish a good stand of T. latifolia for passive treatment and phytoremediation of industrial effluents, before draining the polluted water into fresh water bodies like rivers and streams.

Der Flussname Inn, Ockhams Rasiermesser und moderne Indogermanistik

Some European hydronyms (among them also the river-name Inn) have sometimes been explained based on a root PIE “ *en‑/*on‑” (modern spelling: PIE *h₁en(H)-), which has usually been given the meaning ‘flow, river’ vel sim. This root cannot even be found in Pokorny’s Indogermanisches etymologisches Wörterbuch (1959). No real proof for that root has been found in the appellative lexicon of any Indo-European language. Moreover, there aren’t any sure continuations of that root in the onymic lexicons of those languages. All names put forward as arguments can either be explained based on a root PIE *pen-/*pon- ‘swamp, (standing) water’ (because they are Celtic) or based on a root PIE *h₂en- ‘haul (water)’. As long as no proof of an appellative use of a root PIE *h₁en(H)- can be offered, which alone might tell us, what that root actually meant, the application of ‘Occam’s razor’ leaves us no other choice but to explain all regarding names from the other two roots.

Land Cover Dynamics on the Lower Ganges–Brahmaputra Delta: Agriculture–Aquaculture Transitions, 1972–2017

Aquaculture in tropical and subtropical developing countries has expanded in recent years. This practice is controversial due to its potential for serious economic, food security, and environmental impacts—especially for intensive operations in and near mangrove ecosystems, where many shrimp species spawn. While considerable effort has been directed toward understanding aquaculture impacts, maps of spatial extent and multi-decade spatiotemporal dynamics remain sparse. This is in part because aquaculture ponds (ghers) can be challenging to distinguish from other shallow water targets on the basis of water-leaving radiance alone. Here, we focus on the Lower Ganges–Brahmaputra Delta (GBD), one of the most expansive areas of recent aquaculture growth on Earth and adjacent to the Sundarbans mangrove forest, a biodiversity hotspot. We use a combination of MODIS 16-day EVI composites and 45 years (1972–2017) of Landsat observations to characterize dominant spatiotemporal patterns in the vegetation phenology of the area, identify consistent seasonal optical differences between flooded ghers and other land uses, and quantify the multi-decade expansion of standing water bodies. Considerable non-uniqueness exists in the spectral signature of ghers on the GBD, propagating into uncertainty in estimates of spatial extent. We implement three progressive decision boundaries to explicitly quantify this uncertainty and provide liberal, moderate, and conservative estimates of flooded gher extent on three different spatial scales. Using multiple extents and multiple thresholds, we quantify the size distribution of contiguous regions of flooded gher extent at ten-year intervals. The moderate threshold shows standing water area within Bangladeshi polders to have expanded from less than 300 km2 in 1990 to over 1400 km2 in 2015. At all three scales investigated, the size distribution of standing water bodies is increasingly dominated by larger, more interconnected networks of flooded areas associated with aquaculture. Much of this expansion has occurred in immediate proximity to the Bangladeshi Sundarbans.

MITIGATION YIELD SCALED METHANE EMISSION FROM RICE GROWN IN WATER STRESS CONDITIONS WITH BIOCHAR AND SILICATE AMENDMENTS

Climate change and water scarcity may badly affect existing rice production system in Bangladesh. With a view to sustain rice productivity and mitigate yield scaled CH4 emission in the changing climatic conditions, a pot experiment was conducted under different soil water contents, biochar and silicate amendments with inorganic fertilization (NPKS). In this regard, 12 treatments combinations of biochar, silicate and NPKS fertilizer along with continuous standing water (CSW), soil saturation water content and field capacity (100% and 50%) moisture levels were arranged into rice planted potted soils. Gas samples were collected from rice planted pots through Closed Chamber technique and analyzed by Gas Chromatograph. This study revealed that seasonal CH4 emissions were suppressed through integrated biochar and silicate amendments with NPKS fertilizer (50–75% of the recommended doze), while increased rice yield significantly at different soil water contents. Biochar and silicate amendments with NPKS fertilizer (50% of the recommended doze) increased rice grain yield by 10.9%, 18.1%, 13.0% and 14.2%, while decreased seasonal CH4 emissions by 22.8%, 20.9%, 23.3% and 24.3% at continuous standing water level (CSW) (T9), at saturated soil water content (T10), at 100% field capacity soil water content (T11) and at 50% field capacity soil water content (T12), respectively. Soil porosity, soil redox status, SOC and free iron oxide contents were improved with biochar and silicate amendments. Furthermore, rice root oxidation activity (ROA) was found more dominant in water stress condition compared to flooded and saturated soil water contents, which ultimately reduced seasonal CH4 emissions as well as yield scaled CH4 emission. Conclusively, soil amendments with biochar and silicate fertilizer may be a rational practice to reduce the demand for inorganic fertilization and mitigate CH4 emissions during rice cultivation under water stress drought conditions.

Estimating the Importance of Hydrologic Conditions on Nutrient Retention and Plant Richness in a Wetlaculture Mesocosm Experiment in a Former Lake Erie Basin Swamp

The western basin of Lake Erie, the shallowest of the Laurentian Great Lakes in North America, is now plagued by harmful algal blooms annually due to nutrient discharges primarily from its basin. Water quality was impacted so significantly by toxic cyanobacteria in 2014 that the city of Toledo’s water supply was shut off, affecting hundreds of thousands of residents. A new agricultural land management approach, ‘wetlaculture (=wetland + agriculture)’, has a goal of reducing the need for fertilizer applications while preventing fluxes of nutrients to downstream aquatic ecosystems. A wetlaculture mesocosm experiment was set up on agricultural land near Defiance, Ohio, on the northwestern edge of the former ‘Great Black Swamp’. The mesocosms were randomly assigned to four hydrologic treatments involving two water depths (no standing water and ~10-cm of standing water) and two hydraulic loading rates (10 and 30 cm week−1). Nearby agricultural ditch water was pumped to provide weekly hydraulic loading rates to the mesocosms. During the two-year period, the net mass retention of phosphorus from the water was estimated to have averaged 1.0 g P m−2 in the wetland mesocosms with a higher hydraulic loading rate, while the highest estimated net nitrogen mass retention (average 22 g N m−2) was shown in the wetland mesocosms with 10 cm of standing water and higher hydraulic loading rate. Our finding suggests that hydrologic conditions, especially water level, contribute directly and indirectly to nutrient retention, partially through the quick response of the wetland vegetation community. This study provides valuable information for scaling up to restore significant areas of wetlaculture/wetlands in the former Great Black Swamp, strategically focused on reducing the nutrient loading to western Lake Erie from the Maumee River Basin.

Examining patterns and drivers of variability in playa water status on the High Plains of western Kansas, 2016–2019

Playa wetlands are widely distributed across the High Plains of the central United States, providing a range of ecosystem services, such as groundwater recharge, surface water storage, and wetland habitat. Although playas are essential resources, few studies have examined the variability and controls on playa water storage. The purpose of this project is to determine how playa and watershed morphology, watershed land cover, and precipitation patterns affect timing and duration of water storage in playas. This project focuses on 92 playas distributed throughout a 10-county region in western Kansas. Playa and watershed morphology were calculated in a GIS environment and classified into quartiles based on playa and watershed surface area. Watershed tilled index (i.e., percent cropland versus grassland) was determined using 2016, 2017, 2018, and 2019 Cropland Data Layers available from the National Agricultural Statistics Service and classified as either cropland (more than 75% cropland), grassland (more than 75% grassland), or mixed. Monthly precipitation data for 2016–2019 were compiled from the Oakley 22S High Plains Regional Climate Center weather station. Playa water status for 2016–2019 was classified monthly as either standing water or dry (i.e., no visible standing water) by visually examining four-band satellite imagery with 3.7 m resolution available from Planet Explorer (www.planet.com). Playa water status is influenced by a combination of factors, including playa and watershed morphology, watershed land cover, and precipitation patterns. Larger playas have larger watersheds and standing water more frequently and for longer periods than smaller playas. Playas in cropland watersheds store water more frequently and for longer periods than playas in grassland watersheds, though differences are not statistically significant. Standing water within playas is positively correlated with monthly precipitation and reflects a short-term response to precipitation patterns, regardless of playa size or watershed land cover. The strongest controls on playa water status are playa area, monthly precipitation, and watershed area. Playas are critical resources for the High Plains, providing a range of ecosystem services that are dependent upon the playa’s ability to store water. Playa functions are under continued threat from cropland expansion, climate change, and playa and watershed modifications. To sustain playa functions in Kansas, efforts should focus on conserving larger grassland playas and reducing sediment inputs to playas in cropland watersheds.

Florida Container Mosquitoes

Container mosquitoes inhabit small natural and artificial water-filled vessels during their immature stages. This publication lists and illustrates fifteen species of them, including two exotics that are the most important vector species of dengue, chikungunya, yellow fever, and Zika viruses. It also describes available control measures, the best for homeowners being to eliminate aquatic habitat by draining standing water in containers near homes.