Upland Wetland Research Articles

Geomorphic-centered classification of wetlands on the Qinghai-Tibet Plateau, Western China

AbstractIn this paper a geomorphic-centered system was proposed for classifying the wetlands on the Qinghai-Tibet Plateau in western China, where the flora comprises primarily grasses. Although the geomorphic properties (e.g., elevation and morphology) of wetlands form the primary criteria of classification, this system also takes hydrological processes into implicit consideration. It represents an improvement over the hydrogeomorphic perspective as the relative importance of the two components (wetness and landform) of wetlands is clearly differentiated. This geomorphic-centered perspective yields insights into the hydrogeomorphic dynamics of plateau wetlands while indicates their vulnerability to change and degradation indirectly. According to this geomorphic-centered perspective, all plateau wetlands fall into one of the seven types of alpine, piedmont, valley, terrace, floodplain, lacustrine, and riverine in three elevational categories of upland, midland, and lowland. Upland (alpine and piedmont) wetlands with the steepest topography are the most sensitive to change whereas midland (floodplain, terrace and valley) wetlands are less vulnerable to degradation owing to a high water reserve except terrace wetlands. They have a dry surface caused by infrequent hydrological replenishment owing to their higher elevation than the channel. Low lying (lacustrine and riverine) wetlands are the most resilient. The geomorphic-centered perspective developed in this paper provides a framework for improving recognition and management of wetlands on the Plateau. Resilient wetlands can be grazed more intensively without the risk of degradation. Fragile and vulnerable wetlands require careful management to avoid degradation.

Spatial identification and optimization of upland wetlands in agricultural watersheds

Wetland ecosystems are considered as potential ecological solutions for increasing the capacity of watersheds to store runoff waters upstream, and thereby, decrease risk of downstream flooding. Especially in tile-drained agricultural landscapes, wetlands constructed to intercept these tiles can serve as storage basins for agricultural runoff, leading to both reduction in peak runoff flows and diminished transport of agricultural nutrients. The objective of this study was to develop a watershed-scale methodology for identifying potential sites for wetlands in a tile-drained landscape in the Midwestern USA, and for optimizing the spatial distribution of these wetlands for reductions in peak runoff flows. The benefits of this methodology is demonstrated by using it for selecting appropriate wetland restoration and/or creation sites in Eagle Creek Watershed (ECW), located 10 miles northwest of Indianapolis, IN, USA. Results show that a large number of potential sites could be identified (e.g., 2953 sites in ECW), and with a choice of effective wetland design parameters and with spatial optimization of their areas, locations, and drainage areas, it is possible to achieve significant peak flow reductions with fewer sites and smaller wetlands.

Attenuation of Nitrogen, Phosphorus and E. coli Inputs from Pasture Runoff to Surface Waters by a Farm Wetland: the Importance of Wetland Shape and Residence Time

Water quantity and quality were monitored for 3 years in a 360-m-long wetland with riparian fences and plants in a pastoral dairy farming catchment. Concentrations of total nitrogen (TN), total phosphorus (TP) and Escherichia coli were 210–75,200 g N m−3, 12–58,200 g P m−3 and 2–20,000 most probable number (MPN)/100 ml, respectively. Average retentions (±standard error) for the wetland over 3 years were 5 ± 1%, 93 ± 13% and 65 ± 9% for TN, TP and E. coli, respectively. Retentions for nitrate–N, ammonium–N, filterable reactive P and particulate C were respectively −29 ± 5%, 32 ± 10%, −53 ± 24% and 96 ± 19%. Aerobic conditions within the wetland supported nitrification but not denitrification and it is likely that there was a high conversion rate from dissolved inputs of N and P in groundwater, to particulate N and P and refractory dissolved forms in the wetland. The wetland was notable for its capacity to promote the formation of particulate forms and retain them or to provide conditions suitable for retention (e.g. binding of phosphate to cations). Nitrogen retention was generally low because about 60% was in dissolved forms (DON and NOX–N) that were not readily trapped or removed. Specific yields for N, P and E. coli were c. 10–11 kg N ha−1 year−1, 0.2 kg P ha−1 year−1 and ≤109 MPN ha−1 year−1, respectively, and generally much less than ranges for typical dairy pasture catchments in New Zealand. Further mitigation of catchment runoff losses might be achieved if the upland wetland was coupled with a downslope wetland in which anoxic conditions would promote denitrification.

Analysis of Plant Species Community within Upland Wetlands at Mt. Ilgwang

This study characterized the full range of vegetation in a upland wetland (marshland) in Korea. Classified community types were used to describe vegetation at the marshland and adjacent areas. The communities contained 44 species of vascular plants and all species were identified into four plant community types. The Rhododendron yedoense f. poukhanense type and Lespedeza cyrtobotrya type had a high representation infacultative upland species (FU) and obligate upland species (OU), respectively. The monocot type was dominant in marshland by Miscanthuns saccharifloruc and contained 14 species. Together the three areas contained four species, with the strongest indicator species being Ranunculus acris var. nipponicus, Rhododendron yedoense f. poukhanense, Hemerocallis fulva, and Miscanthuns sinensis var. purpurascens. Shannon-Weaver index of diversity also varied among the community types (F = 18.9, df = 2), with the types FU having significantly higher value (3.467) than the others (1.125 for type FW and 1.239 for type OU).

Winter habitat selection by the Vulnerable black-necked craneGrus nigricollisin Yunnan, China: implications for determining effective conservation actions

AbstractHabitat change has major effects on wildlife and it is important to understand how wild animals respond to changing habitats. Dashanbao National Nature Reserve, in north-east Yunnan, China, which was established for the protection of the black-necked craneGrus nigricollis, other wintering waterbirds and the upland wetland ecosystem, recently began converting farmland to grassland and woodland. With respect to this policy we studied habitat selection by black-necked cranes in the Reserve from November 2006 to April 2007. Farmland, grassland, marsh and water were used by black-necked cranes but no cranes occurred in man-made woodland. Black-necked cranes showed the least preference for grassland and no significant differences were detected in the species’ preference for the other three habitats. However, black-necked cranes exhibited different behavioural responses to the four habitats: farmland and grassland were their main foraging sites. Principle component analysis verified that a foraging-related component was the first factor determining habitat selection. Cranes used habitat close to their roosts with short grass, shallow water and less disturbance by human activity. Our results indicate that the policy of converting farmland and grassland to woodland is not beneficial for conservation of the crane. For effective conservation of the black-necked crane scientific habitat management that takes into account habitat selection by the species is required, with the retention of some farmland and restoration of wetlands.

Wetland complexes and upland–wetland linkages: landscape effects on the distribution of rare and common wetland reptiles

AbstractWe used landscape ecology concepts to test the importance of upland–wetland linkages on the distribution of two common wetland species, the northern watersnake Nerodia sipedon sipedon and midland painted turtle Chrysemys picta marginata, and two rare wetland species, the copper‐bellied watersnake Nerodia erythrogaster neglecta and Blanding's turtle Emydoidea blandingii. We tested if connectivity (proximity to other wetlands), connectivity quality (wetland distance to roads and forest area within 30, 125, 250, 500 and 1000 m of the wetland), and patch size (wetland size and shoreline length) affected the distribution of these four species. Our results show that both common species were more likely to occur in larger, less isolated wetlands, but their distribution were not influenced by proximity to roads or the amount of adjacent forest area surrounding the wetland. Both rare species were more likely to occur in wetlands that were farther away from roads and that had more surrounding forest. Proximity to other wetlands was not a significant predictor of either rare species' distribution. Our results suggest that management practices should focus on protecting wetland complexes and maintaining upland–wetland linkages by improving landscape connectivity, increasing forest area surrounding wetlands and reducing road effects.

Soil moisture variability across climate zones

Variability in soil moisture is controlled by temporal variability in atmospheric conditions and spatial variability in land‐surface conditions. Observations of soil moisture have revealed a variety of patterns – generally, in semiarid regions variance increased as mean soil moisture content increased, in humid regions variance decreased as mean soil moisture content increased, and in temperate regions variance peaked at intermediate moisture contents. We collected soil moisture data at Big Meadows, an upland wetland in Shenandoah National Park, Virginia, and we observed peak variance at intermediate moisture contents, consistent with other sites in temperate climate zones. A modified soil moisture dynamics model was used to examine how soil moisture patterns evolve through time, how topography, soil, and vegetation affect these patterns, and how the trends observed across climate zones can be explained. The trends observed relate to theoretical bounds on soil moisture distributions, i.e., the wilting point and the porosity.

Towards Sustainable Agricultural Development of Kotawaringin Barat Regency, Kalimantan, Indonesia

ABSTRACT A study was conducted to establish an approach to land development for sustainable agriculture of the Kotawaringin Barat Regency, Kalimantan, Indonesia. The study comprised three parts, namely, developing the agroecological zone (AEZ), establishing agricultural land regions, and determining land suitability of these regions for several existing crops. On the basis of land characteristics, climatic data, 4-slope classes, and the isohyperthermic temperature regime, Kota-waringin Barat Regency was divided into four main agroecological zones. The area covered by zone I, II, III, and IV were 12.45%, 33.4%, 10.89%, and 43.26%, respectively. The steep upland areas of zone I would be left undisturbed for native forest and wildlife reservation. The moderately steep areas of zone II would be suitable for hardy perennial crops. The gentle sloping areas of zone III would be suitable for agroforestry and annual crop cultivation. Depending upon the soil types, the lowland, and swampy areas of zone IV would either be left for mangrove forest production or for annual crop cultivation. Overlaying the AEZ map with the present land use map generated an agricultural land region map, creating areas known as extensification, intensification and conservation zones. These areas are biophysically determined and ecologically sustainable. More than 60% of the total land area of Kotawaringin is suitable for agriculture, leaving almost 40% for native forest conservation. The arable agricultural lands under the extensification and intensification zones were evaluated for their suitability to some existing perennial and annual crops cultivation. The lands were classified as highly suitable (S1) to marginally suitable (S3) for commercial crops such as rubber and oil palm, and staple food crops like upland rice and wetland rice.

Upland–wetland linkages: relationship of upland and wetland characteristics with watersnake abundance

AbstractLand‐use practices surrounding a wetland may be as important for maintaining wildlife populations as the wetland itself. Although imperiled species may appear to be more impacted than ubiquitous species from changes in the landscape surrounding wetlands, studies of common wetland species are useful for conservation because they provide insight into why some species persist despite landscape changes. We therefore investigated the relationship between connectivity, measured as the wetland distance to other wetlands; connectivity quality, implied by wetland distance to roads and forest area within 30, 125, 250, 500 and 1000 m buffer zones around the wetland; and patch size as indicated by wetland size with northern watersnake Nerodia sipedon sipedon abundance. Our results suggest that both upland and wetland characteristics influence the abundance of N. s. sipedon, as wetland size and wetland connectivity to other wetlands were significantly associated with abundance. Abundance was positively correlated with increasing wetland size and wetland connectivity. We were not able to find a significant relationship between abundance and connectivity quality, and wetland distance to road or forest area within 30, 125, 250, 500 and 1000 m buffer zones. We conclude that wetland conservation should focus on wetland complexes as well as individual wetlands. In addition, common wetland species such as the northern watersnake do not appear to be negatively impacted by modifications to nearby terrestrial habitats, such as deforestation and roads, and may benefit from the creation of larger, permanent wetlands.

Lack of Significant Changes in the Herpetofauna of Theodore Roosevelt National Park, North Dakota, Since the 1920s

Abstract We surveyed 88 upland wetlands and 12 1-km river sections for amphibians in Theodore Roosevelt National Park, North Dakota, during 2001–2002 to gather baseline data for future monitoring efforts and to evaluate changes in the distribution of species. We compared our results to collections of herpetofauna made during 1920–1922, 1954 and 1978–1979. The boreal chorus frog (Pseudacris maculata) was the most common amphibian in upland wetlands, followed by the tiger salamander (Ambystoma tigrinum), Woodhouse's toad (Bufo woodhousii), northern leopard frog (Rana pipiens), plains spadefoot (Spea bombifrons) and the Great Plains toad (B. cognatus). Bufo woodhousii was the only species that bred in the river. Our records for reptiles are less complete than for amphibians but no losses from the community are evident. The herpetofauna in Theodore Roosevelt National Park seems unchanged during at least the last half-century and likely since 1920–1922.

Holocene vegetation change, Aboriginal wetland use and the impact of European settlement on the Fleurieu Peninsula, South Australia

A fossil pollen and charcoal record from a cyperaceous swamp on the Fleurieu Peninsula, South Australia, was investigated to provide a history of pre and post-European settlement vegetation change. It was found that the swamp initiated sometime before 8220 calibrated years BP. High rates of peat development and the expansion of swamp species between 7000 BP and 4500 cal. BP indicated wet conditions at that time. The swamp became drier in the late Holocene and some peat may have been lost through deflation. Macroscopic charcoal and Typha pollen suggested that Aborigines deliberately burned the upland wetlands during the mid to late Holocene. Prior to European settlement climate changes generated community shifts in the terrestrial vegetation. The record revealed a transition from an early Holocene Eucalyptus woodland to an Allocasuarina wet-heath in the humid mid-Holocene, a community type with no modern analogue in the region. In the drier late Holocene, a Eucalyptus-dominated woodland returned. The impacts of European settlement were clearly seen in changes in sedimentation rates and in both terrestrial and wetland flora. Allocasuarina verticillata declined early in the European period and fire tolerant species were promoted, before the almost complete removal of native vegetation through broad scale land clearance and its replacement with nonnative pasture species. Compositional changes to the swamp flora were marked through the European phase with Acacia expanding early in settlement and later being replaced by Leptospermum, in response to changed fire and regional hydrological regimes. The impact of European land use is discussed in relation to Holocene climate-driven vegetation changes and aspects of Aboriginal land use.

Factors affecting Bittern Botaurus stellaris distribution in a Mediterranean wetland

The habitat requirements of a resident population of Bittern Botaurus stellaris were investigated during the breeding season in a Mediterranean upland wetland, with particular reference to the area's isolation from other wetlands, its small size and hydrological conditions. Vegetation structure and water-level were described and associated with booming male and nesting female distribution within the marsh. A logistic regression model showed that water-level was the only significant factor affecting the distribution of booming males, which occupied areas seasonally flooded with shallower water (< 1 m). Females nested in seasonally flooded zones, while vegetation density appeared an important variable for nesting-site choice. Management of the wet area is discussed and the importance of a better understanding of the temporal dynamics of vegetation cover and spatial and temporal variations in water-level, and their possible effects on prey distribution, is highlighted.

Organic matter and soil biota of upland wetlands in Taylor Valley, Antarctica

In January 2001, we surveyed streams and ponds above 300 m a.s.l. in Taylor Valley, South Victoria Land, Antarctica. One pond was examined in detail. Organic materials covered nearly 100% of the adjacent soil to 5–20 m from the shore, with intermittent patches to 80 m. Organic matter averaged 257 g C/m2, and totaled 1,388 kg organic C on the soil around the pond. Soil-moisture content (0.56–12.41%) decreased with distance from shore, whereas pH (7.8–10.8) increased with distance. Electrical conductivity was lowest in the soils <10 m from the pond (416±94 µS/cm). Mineral soil organic C and total N concentrations were greatest between 10 and 30 m from the edge of the pond (1.21±0.37 and 0.13±0.05 mg/g soil, respectively). Soil invertebrates were present in only 50% of samples and included tardigrades, rotifers, and two nematodes, Scottnema lindsayae and Plectus antarcticus. A non-parametric, discriminant function analysis based on soil moisture, soil organic carbon, and electrical conductivity correctly predicted 87.0% of sites that had invertebrates and 70.8% of sites for which invertebrates were absent. Tardigrades, rotifers, and P. antarcticus were found only in the wettest soils nearest the pond whereas S. lindsayae was restricted to drier soils further from shore. Other ponds and streams also showed substantial accumulations of organic matter, suggesting that upland wetlands serve as resource islands in these polar deserts that provide a source of organic matter to nearby soils.

Monitoring herpetofauna in a managed forest landscape: effects of habitat types and census techniques

We surveyed the herpetofaunal (amphibian and reptile) communities inhabiting five types of habitat on a managed landscape. We conducted monthly surveys during 1997 in four replicate plots of each habitat type using several different methods of collection. Communities of the two wetland habitats (bottomland wetlands and isolated upland wetlands) were clearly dissimilar from the three terrestrial communities (recent clearcut, pine plantation, and mixed pine–hardwood forest). Among the three terrestrial habitats, the total herpetofaunal communities were dissimilar ( P<0.10), although neither faunal constituent group alone (amphibians and squamate reptiles) varied significantly with regard to habitat. Three survey techniques used in the terrestrial habitats were not equally effective in that they resulted in the collection of different subsets of the total herpetofauna. The drift fence technique revealed the presence of more species and individuals in every habitat and was the only one to detect species dissimilarity among habitats. Nonetheless, coverboards contributed to measures of abundance and revealed species not detected by other techniques. We suggest that a combination of census techniques be used when surveying and monitoring herpetofaunal communities in order to maximize the detection of species.

Ecological and evolutionary trends in wetlands: Evidence from seeds and seed banks in New South Wales, Australia and New Jersey, USA

AbstractAquatic plants include a variety of life forms and functional groups that are adapted to diverse wetland habitats. Both similarities and differences in seed and seed‐bank characteristics were discovered in comparisons of Australian (New South Wales) temporary upland wetlands with a North American (New Jersey) tidal freshwater marsh having both natural and constructed wetlands. In the former, flooding and drying are unpredictable and in the latter water levels vary diurnally and substrate is constantly moist. The hydrologic regimen provides the overriding selective force, with climate an important second factor. Other factors related to water level, such as oxygen availability, temperature and light, vary spatially and temporally, influencing germination processes, germination rates and seedling establishment. Seed and seed‐bank characteristics (size, desiccation and inundation tolerance, germination cues and seed‐bank longevity and depletion) differ, with the Australian temporary wetland being more similar to the small‐seeded persistent seed bank of the constructed wetland site than to the natural tidal freshwater site with its larger seeds, transient seed bank and seasonal spring germination. Some non‐spring germination can occur in the tidal constructed wetland if the soil is disturbed. In contrast, seeds in the temporary Australian wetlands germinated in response to wet/dry cycles rather than to season. Functional groups (e.g. submerged, amphibious) are more diverse in the Australian temporary wetlands, where all species tolerate drying. We suggest that the amphibious zone, with its hydrologic gradient, is the site of selection pressure determining establishment of wetland plants from seed. In this zone, multiple selective factors vary spatially and temporally.

A spectrofluorimetric study of the binding of carbofuran, carbaryl, and aldicarb with dissolved organic matter

This study examined the binding of carbamate pesticides with dissolved organic matter (DOM) using fluorescence quenching and synchronous scan fluorescence spectroscopy (SSFS). Fluorescence spectra of the three pesticides were characterized as follows: carbofuran and carbaryl fluoresce at 305 and 330 nm, respectively, upon excitation at 276–279 nm, whereas, aldicarb shows broad emission at 350–380 nm upon excitation at 326 nm. A fluorescence quenching technique was used to obtain conditional binding constants for the carbamate pesticides with Aldrich humic acid under fixed conditions of 22°C and pH 6. The binding constant of carbofuran with humic acid is greater than the binding constants of both carbaryl and aldicarb. Estimates were also obtained for the binding of carbofuran with DOM samples from a coniferous forest soil O horizon, a deciduous forest soil O horizon, a sedge marsh wetland, and a stream in the drainage sequence and their molecular weight (MW) fractions. Those conditional binding constants were used to predict the potential transport of carbofuran in the drainage sequence. When binding constants and DOM concentrations were both taken into account, it was found that DOM from the coniferous forest O horizon had the largest capacity to bind and to transport carbofuran in the drainage sequence. SSFS was used to probe the binding mechanisms of DOM with carbofuran. Overall, the potential mobility of carbofuran in the upland–wetland–stream drainage sequence was significantly enhanced via binding with DOM.

The Role of Small Wetlands in Catchment Management: Their Effect on Diffuse Agricultural Pollutants

AbstractDespite extensive interest in natural wetlands and their use in waste‐water technology, little is known about how effective they are for the control of diffuse agricultural pollution. The impact of a small upland wetland located along a drainage line on different storm generated discharge events and resultant downstream nutrient loads over a two year period was assessed. Results for individual events indicated that the relationship between this wetland and its catchment was variable. An annual nutrient budget was determined for this wetland for the period March 1994 to February 1995. The wetland retained 9.7 kg yr−1 (20.5 kg yr−1) of nitrogen and 1.5 kg yrl (±0.1 kg yr−1) of phosphorus which represented 23% of the nitrogen and 38% of the phosphorus that flowed from this catchment. It is concluded that this form of wetland has a role in strategic catchment management for the interception of nutrients flowing from diffuse agricultural sources.

Environmental effects of land use change, as identified by habitat recording: a case study in the Llŷn Peninsula, Wales

A base-line environmental survey in 1972 was repeated in 1987 to test the effectiveness of the methodology in detecting environmental change and in predicting future change. In both cases, the habitats were recorded in a 30 m radius “quadrat” in each of Llŷn's 410 constituent km 2 squares. Fifteen per cent of the area had changed. Improved grassland showed the greatest gain (6·3% of Llŷn), the greatest losses being in arable (1·6%) and marsh (1·9% of Llŷn or 27% of its 1972 cover) habitats. Habitat change was significantly greater at lower altitudes, lesser slopes, gley soils and near the centre of population. In 1972 Llŷn could be divided, by its habitat associations, into upland grassland, improved grassland and wetland groups. By 1987 these became polarized towards an upland and a lowland group only. Agricultural census data showed a marked increase in grassland and in stock rearing, but a decrease in crops. Farm size had increased and farm numbers decreased. This agricultural improvement of economically suitable areas had, by the consequent loss of habitats, increased the uniformity of Llŷn; thus, the two main habitat associations. If land management practices remain the same, it is predicted that there will be a loss, mainly to improved grassland, of 43% of the marshland present in 1987 by the year 2002. There will also be increased losses in other semi-natural vegetation. However, the designation of Llŷn as an Environmentally Sensitive Area should ensure a slowing down of such losses: the method described here provides a means of testing the effectiveness of such a designation. It also demonstrates the importance to nature-conservation of examining changes in large areas rather than in designated sites only.

Rasgos morfoestructurales de la llanura amázonica del Perú: efecto de la neotéctonica sobre los cambios fluviales y la delimitación de las provincias morfológicas

Morphostructural trends of the amazonian regions of Peru: the effect of neotectonics on fluvial changes and upland wetland boundaries Abstracts The Amazonian regions of Peru are discussed within the context of current knowledge on recent Andean tectonics and their impact on river drainage. The main morphostructural provinces are the foothills or Subandean Zone which are bordered on the east by large depressions in the Marañón Basin of northeastern Peru, the Madre de Dios region of southern Peru and further to the east the Brazilian craton (Iquitos Geanticline). The structural framework of the Subandean Zone consists of the Subandean Thrust and Fold Belt (STFB) West which crops out mostly in the Upper Foothills, and the Subandean Tilted Block Zone (STBZ) East which is concentrated mainly in the Lower Foothills. The main rivers which cross the STFB are antecedent or superimposed, but the secondary drainage channels conform to these structures and are subsequent. The STBZ river basins run parallel to the structural contour. The Marañón basin comprises a northern depression along the Pastaza River, and to the south is the large Ucamara depression with its extended floodplains and structurally controlled lakes. To the east, the Iquitos geanticline represents a positively epeirogenic structure on the western border of the South American craton. The rivers showing active meander belts (Marañón, Ucayali and Tapiche) are drained by white (silty) water from the Andes. Watersheds are drained by stable black water (from organic acids) streams with underfit patterns like the Samiria and Pacaya rivers. The underfit pattern is interpreted as the abandonment of formerly active large streams of white water. The position in the depression of the black water streams suggests successive shiftings of the Marañón and Ucayali rivers respectively northward (50 km) and southeastward (100 km) during the recent time, probably the Holocene. The geodynamical environment of the Ucamara depression suggests a close relation between the recent tectonic activity and the successive shifting of the Marañón and Ucayali rivers. The three large areas of swamp and lakes are presented: the Concordia, Puinahua and the Punga lakes. Their features are discussed in relation to deep faults and fold belts in the basement. Neotectonic data as well as data from earthquake focal mechanisms are compared to the present morphostructural scheme of the area, and discussed in term of quaternary tectonic evolution.

Catchment liming and nature conservation

Catchment liming is often a more efficient means of countering the chemical effects of surface water acidification than direct lake liming. However, such liming may cause considerable damage to upland terrestrial ecosystems. Upland wetland communities should not, therefore, be limed and all other proposals for liming should take into account all possible environmental consequences, not just those on the aquatic system, and should be undertaken in full consultation with relevant authorities.