Effect of land use on anuran species composition in north-eastern KwaZulu-Natal, South Africa

Eucalyptus globulus plantations are spreading in the northern areas of the Iberian Peninsula, substituting natural deciduous riparian vegetation. Whereas laboratory studies with leaf litter of this species have found detri- mental effects on detritivorous species, fi eld studies did not support a strong negative effect. Hence, we compared taxon richness, density and biomass of macroinvertebrate assemblages inhabiting streams fl owing through eucalypt plantations with those fl owing through native oak forest. Moreover, we compared traits of leaf eating macroinver- tebrates (shredders) between the two types of streams. Streams fl owing through eucalypt plantations had lower taxon richness, density and biomass of total invertebrates (and particularly of shredders) compared to those fl owing through native forests. Large shredder taxa, such as Echinogammarus spp. & Limnephilidae, showed a signifi cant negative response (in terms of abundance and biomass) to eucalypt cover whereas smaller taxa displayed similar distribution patterns in both habitat types. The grazer Habroleptoides sp. was the only taxon displaying higher den- sities in eucalypt sites, which might be explained by the reduction of competition/predation by other large shred- ders. Shredders at eucalypt sites showed the following traits: small maximum body size, short life cycles, few re- production cycles per year, active dispersal, and ability to feed on food of lower quality. The shredder assemblages in the eucalypt sites shared similarities with those typical of locations where production is limited due to acidity or oligotrophy of the waters. One stream drained both native and eucalypt forest, but the density and biomass of shredders in the eucalypt (downstream) site was very similar to those found in native streams. This result supports the idea that transport of native organic matter from upstream parts of the basin can maintain native invertebrate assemblages in downstream parts where the land use has been changed.

Freshwater ecosystems provide vital resources for humans and support high levels of biodiversity, yet are severely threatened throughout the world. The expansion of human land uses, such as urban and crop cover, typically degrades water quality and reduces freshwater biodiversity, thereby jeopardizing both biodiversity and ecosystem services. Identifying and mitigating future threats to freshwater ecosystems requires forecasting where land use changes are most likely. Our goal was to evaluate the potential consequences of future land use on freshwater ecosystems in the coterminous United States by comparing alternative scenarios of land use change (2001-2051) with current patterns of freshwater biodiversity and water quality risk. Using an econometric model, each of our land use scenarios projected greater changes in watersheds of the eastern half of the country, where freshwater ecosystems already experience higher stress from human activities. Future urban expansion emerged as a major threat in regions with high freshwater biodiversity (e.g., the Southeast) or severe water quality problems (e.g., the Midwest). Our scenarios reflecting environmentally oriented policies had some positive effects. Subsidizing afforestation for carbon sequestration reduced crop cover and increased natural vegetation in areas that are currently stressed by low water quality, while discouraging urban sprawl diminished urban expansion in areas of high biodiversity. On the other hand, we found that increases in crop commodity prices could lead to increased agricultural threats in areas of high freshwater biodiversity. Our analyses illustrate the potential for policy changes and market factors to influence future land use trends in certain regions of the country, with important consequences for freshwater ecosystems. Successful conservation of aquatic biodiversity and ecosystem services in the United States into the future will require attending to the potential threats and opportunities arising from policies and market changes affecting land use.

Neotropical forests show high anuran species richness, but some Brazilian forest formations, like cerradão, semideciduous forests and restingas, remain poorly known. The composition of anuran species were determined for four forest sites belonging to different biomes in southeastern Brazil, based on two complementary techniques (visual encounter survey and survey on breeding sites), both applied simultaneously. A total of 60 anuran species belonging to eight families was recorded. Species richness and levels of endemism were higher in the Atlantic rainforest site. Sites located in the Cerrado domain were more alike than those located in the Atlantic Forest Domain. Similarity in anuran species composition was negatively correlated to the geographical distance among sites, which explains part of similarities in species composition. Factors affecting these occurrence patterns are discussed. One species (if its identity is confirmed) is considered Data Deficient by IUCN (The World Conservation Union), though it is not included in the Brazilian list of threatened amphibians. The presence of certain species with special habitats and microclimate requirements (bioindicators) suggests well-preserved ecosystems.

Understanding the effects of land use on soil structure and nutrients is important for soil and water conservation in an ecologically fragile zone. This study was carried out to examine the variability of physicochemical properties in three different land use types: abandoned land (AL), eucalyptus plantation (EP), and road lawn (RL) sites at soil depths of 0–10 and 10–20 cm in the Leizhou Peninsula, a tropical coastal ecologically fragile zone of South China. Soil physicochemical property patterns exhibited extremely significant differences among the three land uses (p < 0.001) at both soil depths. Soil nutrients, natural water content, and total porosity, from high to low, in the different land use types were RL, AL, and EP, while the bulk density, from high to low, was EP, AL, and RL. Soil total nitrogen, total phosphorus, total potassium, available potassium, exchangeable calcium, exchangeable magnesium, and natural water content exhibited significant differences (p < 0.05) among the three land use types at soil depths of 0–10 and 10–20 cm, while no significant changes were detected regarding soil organic carbon, available phosphorus, and total porosity. The correlation between physical and chemical properties at the 10–20 cm depth (R = 0.97, p < 0.001) was closer and more significant than that at the 0–10 cm depth (R = 0.95, p < 0.01). Overuse of land (EP) without a rest in the ecologically fragile zone leads to soil erosion and compaction. Compared with natural restoration (abandoned land), artificial restoration (road lawn) can improve soil nutrient and water status more quickly, but cannot modify the soil organic carbon and porosity in the short term.

Successful airport operations require effective noise control by both the airport proprietor and local governments. Land use planning approaches are considered to be the effective measure for airport noise mitigation. The main objective of this research is to examine the impact of airport noise on land use and the effectiveness of available land use planning approaches for land use changes. This research also analyzes noise abatement policies and regulations and liability for the noise emission at airports. In order to examine the impacts of airport noise on land use and the effectiveness of available land use planning approaches for land use changes, a case study is conducted at the Des Moines International Airport (DSM), Des Moines, Iowa. Noise exposure conditions at DSM both in 1989 and 2000 are examined. After identifying noise conditions, their impacts in terms of population, dwelling units, and residential land use areas are analyzed. Then, the study analyzes the effects of land use planning approaches by examining the spatial correspondence between the actual land use pattern and the land use pattern identified in the land use planning approaches. Zoning and land use plans are selected as land use planning approaches for this case study. The noise impact analysis and the effectiveness of land use planning approaches are conducted by utilizing Integrated Noise Model, an aircraft noise modeling software, and Arc View, a Geographic Information System software. The case study of the Des Moines International Airport (DSM) revealed that noise exposure conditions significantly improved during one decade. This improvement contributed to a reduction of noise for affected population and residential areas. The results of the analysis of the effectiveness of zoning and land use plans showed that overall land use patterns changed in the direction of land use patterns identified in the land use plan and zoning map. Actual land use patterns in this area did not change against the land use patterns identified in the land use plans and zoning. These results imply that land use planning approach is a relatively important tool to mitigate noise pollution around an airport.

Effects of land use on butterfly (Lepidoptera: Nymphalidae) abundance and diversity in the tropical coastal regions of Guyana and Australia

Soil structure fractal features and soil anti-erodibility were studied by the combinative means of field investigation and laboratory analysis under different land use patterns. The results showed that fractal dimensions of mechanical composition were greater than that of micro-aggregates, and fractal dimensions of water-stable aggregates were greater than that of dry aggregates. Five land use patterns had a high proportion of aggregates measuring >2 mm after dry sieving and <0.5 mm after wet sieving. Soil dispersion was mainly reflected in aggregates that measure between 0.05 to 0.001 mm. Soil anti-erodibility in the Chinese fir plantation and Eucalyptus plantation were higher than those of the tea plantation, loquat orchard and abandoned farmland. Stability of water-stable aggregate was highest in the Chinese fir plantation, followed by the eucalyptus and tea plantations, and it was lowest in the loquat orchards and abandoned farmland. With the exception of coarse dust, changes in the composition of other soil particles of the same size varied according to different land use patterns. Changes in the status of aggregates and the degree of aggregation were inversely related to changes in the dispersive coefficient. Water stability indices and contents of soil organic matter in the Chinese fir plantation, the eucalyptus plantation and loquat orchard were higher than those of the abandoned farmland and tea plantation. From the results, it can be concluded that land use patterns of the Chinese fir and eucalyptus plantations are a reasonable manner for the increases in soil anti-erodibility and improvements in soil structure in the study area. Key words: Soil aggregates, soil fractal feature, soil water stable index, soil organic matter, land use patterns.

Understanding the effects of land use types and slope gradients on the physicochemical properties of soil is essential for sustainable soil management. Therefore, this study was conducted at the Azit subwatershed of Gedebano Gutazer Welene Woreda, Southern Ethiopia, with the objectives to evaluate the effect of land use types, examine the interaction of land use and slope gradient, and evaluate the effect of slope gradient on selected soil physicochemical properties. A total of 27 soil samples using a simple random sampling technique with randomized complete block design from 3 land use types (cultivated, eucalyptus, and grazing lands) ×3 slope gradients (upper 10–15%, middle 5–10%, and lower 2–5% slopes) ×3 replications and depth (0–20 cm) were collected. Results indicated that most of the physicochemical properties of soils were significantly ( P &lt; 0.01 ) affected by land use and slope gradient. Silt and sand particles did not vary significantly ( P &gt; 0.05 ) among the land use types. The interaction effect of land use and slope was not significant ( P &gt; 0.05 ) for most of the soil properties except for organic carbon (OC). Results of data analysis also showed that soil fertility was low under cultivated and eucalyptus lands coupled with the upper slope gradient. Therefore, based on the study’s findings, it can be recommended that integrated soil fertility management practices, such as the addition of soil organic matter and appropriate use of inorganic fertilizers, need to be implemented to restore the lost soil fertility status on the cultivated land and ultimately increase agricultural productivity on a sustainable basis. Eucalyptus plantings should also gradually be replaced by those that assist the soil in restoring its fertility.

Forests store carbon in wood, forest floor, and soil. Carbon stock and distribution between these compartments differ across forests. The Monfragüe National Park (West Spain) is home to a variety of forests resulting from contrasting land use histories. These include holm and cork oak (Quercus ilex and Q. suber) dehesas (open forests with low-intensity agro-silvo-pastoral use), and pine (Pinus pinaster) and eucalypt (Eucalyptus camaldulensis) plantations, which pursued wood production. These uses ceased decades ago. Part of the former eucalypt plantations was removed and planted with native oaks, but the restoration failed leading to a Cistus ladanifer shrubland. In these five vegetation types, we assessed carbon stock and partitioning among above- (tree and shrub canopy, and forest floor) and belowground compartments (roots and soil); we also assessed tree health, and potential for tree regeneration as indicators of carbon stock persistence. We measured tree dimensions, shrub cover and height, and collected forest floor and soil samples for organic carbon analyses. Allometric equations were used to estimate tree and shrub carbon stocks. Plantations were expected to show a less diverse undercanopy but higher carbon stocks than dehesas, whereas dehesas were expected to allocate a greater proportion of carbon belowground, and to exhibit better tree health and regeneration. Total carbon was the highest in the pine and eucalypt plantations, followed by oak dehesas and minimum in the C. ladanifer shrubland. The shrub layer contributed more to the total carbon stock in the C. ladanifer shrubland and in the eucalypt plantation (13-14%), but ≤ 2% in the pine plantation and in the dehesas. The belowground carbon fraction was greatest in the oak dehesas (c.a. 60%), followed by the pine (55%) and eucalypt (46%) plantations. C. ladanifer shrubland showed an unexpectedly high proportion of carbon in the soil, probably due to legacy effects of the former plantation. Tree health was poorest in eucalypts, followed by cork oaks, while pines and holm oaks showed a better condition. Tree regeneration was poor in all forest types, likely due to canopy competition (plantations) and herbivory (dehesas). Although pine and eucalypt plantations store more total carbon, oak dehesas offer more stable storage due to higher belowground carbon. However, regeneration failure threatens their long-term persistence. Our results show that past land use largely determines forest capacity to store and retain carbon over the long term. Enhancing forest resilience should be a central goal of management aimed at strengthening carbon sink services.

The Conde municipality is located in the northern coast of the state of Bahia (NC), northeastern Brazil, and is part of the Atlantic Tropical domain. The anuran fauna of the northern portion of the NC is still poorly known if compared to the southern portion. The Restinga is one of the predominant environments of the coastal plains of the NC and it is characterized essentially by presenting sandy soil covered by herbaceous and shrubby vegetation. The objective of this study was to determine the anuran species composition and diversity for the Restinga of the Conde municipality. Sampling was carried out at night by active search over four periods of five consecutive days each, two over the 'main rainy season' and two in a 'lesser rainy season', using 14 sample units (SUs) and five extra sample plots (EPs). We calculated dominance and species diversity using the Berger-Parker and Shannon-Wiener H' indices, respectively. We used accumulation curves and the Jackknife 1 estimator to estimate anuran species richness, considering only the data obtained from the SUs. We recorded 713 anuran specimens distributed within 33 species, 13 genera and five families (Bufonidae, Craugastoridae, Hylidae, Leptodactylidae and Microhylidae). The Hylidae and Leptodactylidae families had the highest species richness. Considering only the SUs (Jackknife 1 estimator in brackets), we recorded 28 species in the study area (33.9 ± 2.3), 13 in Shrubby Vegetation Zones - SVZ (20.8 ± 2.9) and 25 in Freshwater Wetland Zones - FWZ (28.9 ± 1.9). The abundance and species diversity of the FWZ (n = 638 specimens; H'= 2.4) were higher than those recorded for the SVZ (n = 52 specimens; H' = 1.9). The SVZ and FWZ showed distinct dominant species, wherein Pristimantis paulodutrai was the dominant species in SVZ and Scinax fuscomarginatus in FWZ. The Restinga of the Conde municipality stands out as the one with the highest anuran species richness already recorded considering only SVZ and FWZ. Moreover, its anuran species composition represented 55% of the anuran species known for the NC and included taxa common to three different morphoclimatic domains (Tropical Atlantic, Cerrado and Caatinga).

Effect of land use on shopping trips in station areas: Examining sensitivity to scale

Brazil harbors the greatest diversity of amphibians on the planet although there are few studies dealing with urban fauna. The objective of this study is to describe the species composition and richness of anurans in urban Cerrado fragments from Campo Grande municipality, Mato Grosso do Sul state, central Brazil. The specimens were sampled in three stages through pitfall traps and visual/acoustic surveys. Seventeen species were recorded (17.7% of anuran species registered in Mato Grosso do Sul), with Leptodactylidae and Hylidae being the most represented families. The existence of a high number of green areas and water bodies in the urban area likely favors anuran species in the region. The anuran communities in urban areas of Campo Grande were dominated by species which use a broad range of habitats. In this study there was the record of a new species of anuran, Proceratophrys dibernardoi, for the state of Mato Grosso do Sul. The forest fragments that had the highest similarity for species composition were those with similar environmental conditions. The knowledge of the fauna that occurs in urban areas is important because natural habitats suffer severe fragmentation and degradation and species present in these areas may disappear in a shorter period of time.

Environmental pollution caused by the disposal of chemicals or toxins into the environment represent a great threat to amphibians. In this study, it was evaluated which environmental factors of ponds under the influence of coal-mining influence the composition of anuran species. For this purpose, anuran samples were performed in ponds in coal extraction areas in southern Brazil. Physical and chemical characteristics of water, sediment and structural characteristics of the ponds were determined. The content of copper in the sediments of the ponds was the main variable to explain the composition of pond species. Besides copper, it is evident the relevance of number of vegetation strata at pond border and pond area on the composition of anurans. It is shown that the composition of species in ponds under the influence of mineral coal mining activity may be a result of historical perturbations, remaining only the most tolerant towards colonization. From the results obtained in this work it can be suggested that there is a synergistic interaction between environmental factors and the coal mining effects on the anurans fauna of impacted ponds. Thus, efforts should be directed to elucidate the effects of pollutants exposure levels on the species, the understanding of sub-lethal and lethal effects of each pollutant on each species, as well as how local populations can be maintained through recruiting rates of larvae and anurans of the impacted ponds.

Wetlands of southern Brazil exhibit unique habitat attributes, such as climate pattern and vegetation cover, that can function as an environmental filter for the establishment of species of Neotropical anurans and influence the composition of anuran assemblages. We examined the role of habitat heterogeneity in the composition and relative abundance of anuran species in subtemperate wetlands of southernmost Brazil. We carried out standardized sampling between May 2009 and April 2011 to examine anuran assemblages in marshes associated with grasslands and coastal dunes, as well as habitat heterogeneity. Habitat heterogeneity and anuran species richness were higher in grasslands. Abundance and species dominance, on the other hand, were higher in dunes. This might be due to more restrictive abiotic filters in dunes, such as the low heterogeneity of vegetation cover and lower availability of water bodies. The most common species in grasslands, Leptodactylus cf. latrans, Elachistocleis bicolor, and Pseudis minuta, exhibited a stronger association with habitats with larger and deeper water bodies and with the presence of floating vegetation. The most abundant species found in dunes, Rhinellla arenarum, Odontophrynus maisuma, and Physalaemus biligonigerus, had a stronger association with low vegetation. In addition to habitat associations, the ability to bury themselves might be a behavioral adaptation to dunes that favor species such as O. maisuma and P. biligonigerus, even under extreme microclimatic conditions. Our findings support the importance of the configuration of vegetation cover as well the heterogeneity of water bodies for the establishment of anuran species in subtemperate marshes of southern Brazil.

Studies integrating variation in species composition among sites are useful in understanding the impacts of land-use changes on the spatial distribution of biodiversity. However, the failure to recognize the distinction between beta diversity components, dissimilarity due to species replacement (i.e. turnover) and dissimilarity due to species loss from site to site (i.e. nestedness), can lead to inappropriate use of some indices. Here, we evaluated how the spatial distribution of anuran beta diversity components, turnover and nestedness, is associated with local and landscape descriptors in a tropical agricultural landscape with a recent history of agriculture expansion in south-eastern Brazil. Overall, 27 anuran species were found in the region with average ± SD species richness in each pool of 9.5 ± 3.5 species, ranging from 4 to 15 species. We observed that species turnover was the major component for anuran dissimilarity among pools, indicating that anuran species occurring in species-poor pools are not subsets of anuran species occurring in species-rich pools. Local variables and geographic distance were not important descriptors explaining the variation of anuran beta diversity. In contrast, the distance of the pools to the nearest forest fragment explained 16% of the variance in total beta diversity, 5% of the nestedness component and 2% of spatial turnover. Our results show that pools distributed across farmland landscapes are harbouring different anuran species composition, and together, these pools are contributing to the regional diversity of anurans in this region which is considered one of the most deforested and fragmented within Brazil.