WETLANDS: REFLEXÕES TEÓRICO-CONCEITUAIS ACERCA DO ESTABELECIMENTO DE ÁREAS ÚMIDAS EM TERRAS SECAS

Australian inland riparian wetlands located east of the Great Dividing Range exhibit unique, hydroecological characteristics. These flood-dependent aquatic systems located in water-limited regions are declining rapidly due to the competitive demand for water for human activities, as well as climate change and variability. However, there exist very few reliable data to characterize inundation change conditions and quantify the impacts of the loss and deterioration of wetlands. A long-term time record of wetland inundation maps can provide a crucial baseline to monitor, assess, and assist the management and conservation of wetland ecosystems. This study presents a random forest-based multi-index classification algorithm (RaFMIC) on the Google Earth Engine (GEE) platform to efficiently construct a temporally dense, three-decadal time record of inundation maps of the southeast Australian riparian inland wetlands. The method was tested over the Macquarie Marshes located in the semiarid region of NSW, Australia. The results showed a good accuracy when compared against high-spatial resolution imagery. The total inundated area was consistent with precipitation and streamflow patterns, and the temporal dynamics of vegetation showed good agreement with the inundation maps. The inundation time record was analysed to generate inundation probability maps, which were in a good agreement with frequently flooded areas simulated by a hydrodynamic model and the distribution of flood-dependent vegetation species. The long-term, time-dense inundation maps derived from the RaFMIC method can provide key information to assess the condition and health of wetland ecosystems and have the potential to improve wetland inventory with spatially explicit water regime information. RaFMIC can be adapted over other dryland wetlands, as an effective semiautomated method of mapping long-term inundation dynamics.

Wetland communities are shaped by high levels of stress, disturbance and competition. Using South African palmiet wetlands as a case study (Prionium serratum dominated valley-bottom wetlands), we explore whether autogenic or allogenic succession is the dominant process driving community dynamics in valley-bottom wetlands in drylands. Several wetland rehabilitation programmes in South Africa use the dominant wetland species palmiet (P. serratum) as a pioneer to facilitate recolonization. However research is needed on palmiet wetland dynamics and formation to guide these restoration efforts. We explore vegetation patterns by analyzing which environmental parameters drive dominance of palmiet, resulting in the characteristic patchiness of palmiet wetlands, and which plant functional traits account for this. In 20 plots from three palmiet wetlands distributed across the Cape Floristic Region of South Africa, key soil, groundwater and vegetation parameters, as well as community composition were measured. Twenty-two dominant species were selected and 13 functional traits measured. Soil pH and relative groundwater depth were the main environmental parameters driving community assembly in palmiet wetlands. Palmiet-dominated communities were characterized by greater stem diameter, leaf length–width ratio, leaf area and cellulose and lignin concentration compared to fynbos communities. These traits suggest adaptations to disturbances such as fires (thicker stems) and floods (long, thin leaves, flexible shoots and thicker stems). We propose three hypotheses of palmiet wetland development which shed light on palmiet wetland restoration and highlight gaps for future research.

The influence of environmental factors in a semiarid climate on characteristics of fresh and frozen/thawed sperm collected from collared peccaries (Pecari tajacu) was assessed. Semen from 11 male collared peccaries was collected by electroejaculation during the peaks of the dry and rainy periods while rainfall indices, air temperatures, relative humidity levels, and wind speeds were measured. The number, motility, morphology, osmotic response, and membrane integrity of sperm in the collected ejaculates were assessed. Samples were then frozen in liquid nitrogen, thawed, and reassessed. The rainfall index of the rainy period (73.2 mm) was significantly higher than that of the dry period (13.6 mm) and the relative humidity was significantly higher during the rainy period (74.6%) than it was during the dry period (66.8%). Air temperature and wind speed did not differ between the two periods. Characteristics of sperm in the fresh samples were not affected by environmental parameters. In contrast, computerized analysis revealed that sperm in samples frozen during the rainy period exhibited better post-thaw membrane integrity (28.6 ± 6%), motility (29.5 ± 7.7%), and rapid sperm population (13.7 ± 6.2%) than did sperm in samples frozen during the dry period (23.4 ± 3% membrane integrity, 14.6 ± 4.1% motility, and 4.1 ± 1.2% rapid sperm; p < 0.05). Other characteristics of the frozen/thawed sperm did not differ depending on the period in which they were collected. We demonstrated that environmental parameters did not affect the quality of fresh sperm, but could influence the freezability of sperm collected from collared peccaries raised under a semiarid climate.

Results of a CLM4 Land Surface Simulation over China using a Multisource Integrated Land Cover Dataset

And we thought the Millennium Drought was bad: Assessing climate variability and change impacts on an Australian dryland wetland using an ecohydrologic emulator

Background and Purpose Evapotranspiration is one of the most critical components in the land branch of the hydrological cycle, which, as the link between water and energy cycles, plays an essential role in the interaction of the atmosphere and surface. Getting access to remote sensing images has made it possible to study evapotranspiration spatially and temporally, including actual evapotranspiration (AET) and potential evapotranspiration (PET). Evapotranspiration of the MOD16A2 MODIS sensor can be very useful among remote sensing images due to its very appropriate spatial (500 m) and temporal (8 daily) resolutions in regional studies in areas without data. Materials and Methods This study evaluated the MODIS global terrestrial potential evapotranspiration product (MOD16A2) using two reference evapotranspiration methods of Penman-Monteith FAO 56 and Priestley-Taylor in meteorological stations from 2001 to 2018. The study area is located in the southwestern provinces of Iran (Khuzestan and Bushehr), west of Iran (Hamedan and Kermanshah provinces), and north of Iran (Guilan and Mazandaran provinces), which is classified from arid to perhumid according to the UNESCO method. Then, Penman-Monteith FAO 56 and Priestley-Taylor reference evapotranspiration was prepared using meteorological data with the Evapotranspiration package R software, and the potential evapotranspiration data of the MOD16A2 product was provided using the Google Earth Engine system. Then, these data were compared based on evaluation metrics in different climates. Findings Compared to both the Penman-Monteith FAO 56 and Priestley-Taylor methods, the MOD16A2 product overestimates evapotranspiration in all climate types and has greater variance in data. The statistical properties of the MOD16A2 include: the first and third quarters in arid and semi-arid climates with Penman-Monteith FAO 56 evapotranspiration is less different than the Priestley-Taylor method. In contrast, the first and third quarters of the MOD16A2 are more similar to the Priestley-Taylor evapotranspiration in semi-humid, humid, and perhumid climates. MOD16A2 also estimates the seasonal evapotranspiration cycles well, but the date of the MOD16A2 peaks in all climate types occur mostly with one-week precedence. The evapotranspiration of the MOD16A2 is successful in estimating the Penman-Monteith (Priestley-Taylor) evapotranspiration in arid and semi-arid climates (semi-humid to perhumid climates), particularly semi-arid with cold winters and hot summers climate (perhumid climate), due to the small errors of the model, including PBIAS and RMSE respectively in the range of 40.3-46.5% and 14.19-6.6mm/8d (the range of 72.5-97% and 6-24.5 mm/8d), the high coefficient of the modified agreement index in the range of 0.5-0.61 (0.37-0.5), weighted determination in the range of 0.55-0.63 (0.44-0.51). Moreover, there is a strong positive linear relationship among MOD16A2, Priestley-Taylor, and Penman-Monteith in most climate types, because of their high correlation coefficients (more than 0.85). Conclusion The results of this study indicate less uncertainty in evapotranspiration of the MOD16A2 product with the Penman-Monteith FAO 56 method in the semi-arid and arid climates, especially semi-arid climates. In contrast, in the semi-humid to hyperhumid climates, MOD16A2 product has less uncertainty with the Priestley-Taylor method. Also, the MOD16A2 product has the least uncertainty in the semi-arid climates due to the least errors. Therefore, considering the recent climate change in terms of increasing temperature and consequently increasing evapotranspiration, particularly in arid and semi-arid regions around the world, and proposing the Penman-Monteith FAO 56 as the standard method of estimating evapotranspiration by FAO, the MOD16A2 evapotranspiration can play a crucial role in irrigation planning, water resources management, and drought monitoring in the arid and semi-arid climates without any observed dataset, especially semi-arid climates.

Long-term and widespread wetlands conservation within agricultural working lands remains tenable. There exists a need to identify alternative options for incentivizing wetland maintenance on private property. The objective of this research is to facilitate development of viable options by developing an understanding of how landowners view conservation, including that specifically targeted towards maintenance of wetlands, and what influences their decision regarding conservation program participation. Landowners in the five-state Prairie Pothole Region were surveyed. Most landowners supported use of incentives for wetlands conservation. Fewer supported the options of incentivized regulation, easements, and regulation. Landowners identified contract attributes including payment level and guaranteed source of income as important in their decision-making regarding conservation program participation. Effect of program participation on soil quality and erosion control were also considered important. Other program attribute and external effect factors were of moderate importance, and impact on neighboring properties was not considered important. Revealed decision criteria differed between groups defined by operation as including livestock, residence as on-farm, gender, previous or current participation in the Conservation Reserve Program, and support of various policy options for wetlands conservation. Attitudinal questions revealed that landowners in general agreed that they should be consulted on wetlands programs, promoting healthy ecosystems is a landowner’s responsibility, and landowners have the right to decide land use, should be compensated for land use choices that benefit the environment, including for maintenance of wetlands, and should be able to farm wetlands. They agreed that wetlands are important for wildlife and their conservation is important, although agreement that it is important to protect wetlands on private and public lands and especially that small wetlands benefit their operations tended toward neutral. Landowners were neutral on whether current conservation programs are effective and there should be regulations to control the conversion of naturally-occurring wetlands on agricultural land. Landowners with a CRP contract history were more supportive of the role of and need to protect wetlands, and had a lower level of agreement that decisions on land use are their right and that landowners should be able to farm their wetlands than those without. Members of general and crop-specific farm organizations were more strongly in agreement with landowners’ rights than non-members and less supportive of the role of wetlands and the need and policy tools to protect them. Members of Farmers Union and three crop commodity organizations also more strongly agreed that farmers should receive compensation when land use choices benefit the environment than non-members. Alternatively, conservation organization member agreement was higher than that of non-members that small wetlands benefit their operations, that it is important to protect wetlands, and that conservation of wetlands is important, and was lower for statements reflecting landowner rights.

This article highlights the relationship between speleothems growing inside gypsum caves and the particular climate that existed during their development. Speleothems in gypsum caves normally consist of calcium carbonate (calcite) or calcium sulphate (gypsum) and the abundance of such deposits greatly differs from zone to zone. Observations carried out over the last 20 years in gypsum caves subjected to very different climates (Italy, Spain, New Mexico, northern Russia, Cuba, Argentina) highlight wide variation in their cave deposits. In arid or semi-arid climates, the speleothems are mainly composed of gypsum, whilst in temperate, humid or tropical regions, carbonate formations are largely predominant. In polar zones no speleothems develop. These mineralogical details could be useful paleoclimatic indicators of climate change. The interpretation proposed is based on the fact that in gypsum karst the kind of speleothems deposited is determined by competition between the two principal mechanisms that cause precipitation of calcite and gypsum. These mechanisms are completely different: calcite speleothem evolution is mainly controlled by CO2 diffusion, while gypsum deposits develop mostly due to evaporation. Therefore, the prevalence of one kind of speleothem over the other, and the relationship between the solution–precipitation processes of calcite and gypsum, may provide evidence of a specific paleoclimate. Additionally, other non-common deposits in gypsum caves like moonmilk, cave rafts and dolomite speleothems can be used as markers for the prevalence of long, dry periods in humid areas, seasonal changes in climate, or rainfall trends in some gypsum areas. Moreover, the dating of gypsum speleothems could contribute paleoclimatic data relating to dry periods when calcite speleothems are not deposited. In contrast, the dating of calcite speleothems in gypsum caves could identify former wet periods in arid zones.

Wetlands are areas permanently or seasonally flooded by water where plants and animals have become adapted over time. They provide critical ecosystem services and contribute to the national economy both directly and indirectly. The Ewaso Narok Wetland is an important ecosystem providing water, farming land and pasture for the livestock. Despite its importance, the wetland is threatened by human activities such as over-cultivation and overgrazing. Therefore, there is a need for sustainable management of the wetland in order to increase its contribution to livelihoods of the current and future generations. The objective of this study was to characterize the major wetland users, to assess the determinants of the individual rate of time preference and resource use behavior among the users. Stratified simple random sampling technique was used to select 99 pastoralists, 95 commercial and 106 small scale farmers in Ewaso Narok Wetland, Kenya. A questionnaire was used to collect household level data. Descriptive statistics, cross tabulations, one-way ANOVA with Tukey's HSD test were used to characterize the wetland users. Hyperbolic model was used in after the choice and matching tasks in calculating the individual rate of time preference while land use intensity index was used as a proxy for the resource use behaviour. Seemingly unrelated regression estimator (SURE) model was used to identify the factors influencing the individual rate of time preference and resource use behavior of the wetland users. Results show that the individual rate of time preference was influenced positively by the size of land area under crop, conflicts among the users, being a commercial farmer and the distance of a homestead to piped water. The resource use behavior was influenced positively by the individual rate of time preference, household size, the number of years of using the wetland and tropical livestock units and negatively by membership to credit lending groups, the level of education, and security of land tenure. The study concludes that the individual rate of time preference was the major contributor of the high intensity of land use and hence its determinants should be considered in sustainable management of the Ewaso Narok Wetland. Consequently, the study recommends that there should be a provision of title deeds to users in areas outside the wetland area to facilitate sustainable wetland use. Diversification into alternative income generating activities should be encouraged through groups and encourage infrastructural development like installation of piped water as an alternative source of resource to minimize dependency on the wetland.

The current study analyzed appropriateness of abandoned rice paddy wetlands as habitats for the Amphibia by assessing functions and value of abandoned rice paddy wetlands within land development districts as a habitat for living creatures and researching into the Amphibia living in the subject districts. For this purpose, the study designated abandoned rice paddy wetlands within Hwaseong A District and Pangyo B District under land development as subject lands. Those wetlands went through succession after abandonment of farming. Detailed study results are as follows. From classification of wetland types and an analysis of their characteristics, it was found that herbaceous plants such as smartweed communities, horsetail communities and reed communities, and woody plants such as pussy willow communities appeared in both districts. These abandoned rice paddy wetlands shows typical characteristics of palustrine wetlands. As a result of a vegetation structure research, it was observed that succession has been progressed for at least over 2~3 years. In assessment of wetland functions by item, it was found that they are developing into fine wetlands in terms of functions because they are ranked over Moderate Class except separate distance from streams. Also from a research into animals living in the abandoned rice paddy wetlands, it was found that main inhabitants are Rana nigromaculata,Rana dybowskii, Hyla japonica, Bufo bufo gargarizans, etc. It can be confirmed that the abandoned rice paddy wetlands are providing appropriate conditions as habitats to the Amphibia in a view that those species have life cycles of inhabitation (shores and wetlands) - egg-laying (rice paddy, puddles and swampy places) - hibernation (rice field banks and swampy places). From this point of view, it was found that abandoned rice paddy wetlands that developed because of abandonment of farming can be used as means to improve structure and functions of habitats.

The aim of this study was to assess the causes of Boye wetland degradation and to identify the bird species composition of the wetland. To achieve the stated objective, group discussion with the local communities was carried out on the causes of wetland degradation and prioritizations were done. In addition, soil samples were collected from wetland and converted lands (agriculture, grazing and Eucalyptus plantation land). Identification and recording of avian species composition was conducted by direct observations using binoculars and standard manual for bird identification. The results of discussion revealed that agriculture land expansion, over grazing, waste disposal in the wetland from Jimma town and Eucalyptus plantation were the major causes for Boye wetland degradation. Statistically significant difference (P<0.05) was observed between wetland and converted lands for pH and EC with the highest mean value on converted land. However, a significant difference (P<0.01) was observed for OC (%) and TN (%) with the highest mean value at wetland. Furthermore, 36 bird species were identified; among these, two are endemic and three near endemic species. Balearica pavonina and Balearica regulorum vulnerable species and Macronyx flavicollis was near threatened species were also found in the wetland. To protect these birds and the biodiversity of Boye wetland, restoration and protection programs should be established to avoid further degradation. Key words: Boye wetlands, land use change, bird diversity, conservation.

Wetlands are ecosystems in which water covers the land. They provide economical, ecological, societal and recreational benefits to humans. Although complete documentation is lacking, wetlands make a significant part of Ethiopia covering an area of 13,700 km2. Wetlands with a great potential for ecotourism development in the country include the rift valley lakes, the floodplains in Gambella, the Awash River Gorge with spectacular waterfalls, the Lake Tana and the Lake Ashenge, the Wenchi Crater Lake and the Wetlands in Sheko district are among others. Similarly, the Wetlands of Ethiopia are home to various aquatic biodiversity. Some of the biodiversity potential areas are the Cheffa Wetland and Lake Tana basin in the North, the rift valley lakes namely, Lake Zeway, Abaya and Chamo, and the Baro River and the Dabus Wetland in the Western Ethiopia. However, the wetlands in the country are impacted by a combination of social, economic, development related and climatic factors that lead to their destruction. Correspondingly, the wetlands holding a considerable biodiversity potential in the country lack adequate management. To address the challenges and enhance the wetland’s role in ecotourism and biodiversity, a sustainable form of wetland resource use should be developed. As a result, integrating wetlands with ecotourism and developing as livelihood option for local communities is important for sustainable conservation of wetlands. Awareness rising, empowering stakeholders involved in wetland resource conservation, enhancing stakeholders’ participation, undertaking the restoration of degraded wetlands and promoting scientific studies on wetlands of the country are crucial to conserve wetlands and at the same time promote their ecotourism and biodiversity importance. Moreover, implementing the integrated wetland resource management approach and addressing policy, management and coordination issues that arise on wetland resource conservation aids to promote the significance of wetlands in ecotourism and biodiversity conservation in Ethiopia. Key words: Wetlands, ecotourism, biodiversity conservation, implication, Ethiopia.

Sea-level rise enhances carbon accumulation in United States tidal wetlands

Genetic variation and genetic structure of black spruce (Picea mariana L.) populations growing in wet land (lowlands) and dry lands (uplands) with different levels of metal contaminations were analyzed using ISSR. Polymorphic loci (P%) ranged from 65% to 90% with a mean of 75%. Nei’s gene diversity (h) varied from 0.264 to 0.359 with a mean of 0.310, and Shannon’s index (I) ranged from 0.381 to 0.524 with a mean of 0.449. The level of genetic variation was higher in populations from wet lands than those from dry lands. Variation within populations accounts for most of total genetic variation. The genetic distance among the black spruce (P. mariana) populations ranged from 0.171 to 0.351. The present study indicates that genetic variation and long-term exposure to metals (more than 30 years) are not associated. Cytological analysis of black spruce seeds from metal-contaminated and -uncontaminated areas showed normal mitotic behavior during prophase, metaphase, anaphase, and telophase.

According to the natural and climatic conditions, Russia is located in a zone of risky agriculture: there is a precipitate deficit on 80% of arable land, and excessive over moistening on 10% of arable land. This is also complicated by climate aridization. In drought years it is practically impossible to implement intensive agrotechnologies and adaptive-landscape farming systems without the use of land reclamation. Currently, in Russia, the total area of irrigated lands is 4.27 million hectares and 4.8 million hectares of drained lands. The average productivity of irrigated land is 2.9 tonnes of grain units/ha. In the case of land reclamation, it is possible to increase the productive potential by 3-4 times. The methodology of increasing the productive potential of agricultural lands by irrigation and drainage reclamation based on the energy evaluation of land reclamation activity is proposed. The energy assessment includes the calculation of the bioclimatic potential, the energy assessment of the state of the soil and the vegetation cover. For the energy estimation of land reclamation, a new indicator is proposed a turbulent energy output, the difference between the radiation balance, the energy of soil formation, and the energy accumulated in soil humus and crop production. This makes it possible to predict the productive potential of agricultural land, depending on the amount of energy invested in land reclamation. The proposed approach makes it possible to move from a real evaluation to a unified energy estimate. The calculations of productivity according to the developed method for various natural zones of the European part of Russia are performed. Chernozems showed the greatest productive potential. It reaches 7.7 tonnes of grain units/ha, and in case of irrigation it can increase up to 10-12 tonnes/ha; the productivity of sod podzol and gray forest soils under natural conditions does not exceed 1.3-2.0 tonnes of grain units/ha, while irrigation productivity will increase to 6-8 tonnes of grain units/ha. Irrigation in the semi-desert and desert zones of the European part of Russia allows increasing their productivity up to 5 times. The proposed method allows selecting the most favorable zoning soils for the reclamation, justifying the crops that ensure the maximum yield in these soil and climatic conditions. The article shows that food security will be ensured during the development of land reclamation in soil and climatic conditions of excessive and insufficient moisture.