<Emphasis Type="Italic">In situ</Emphasis> conservation and genetic diversity of three populations of <Emphasis Type="Italic">Gossypium mustelinum</Emphasis> Miers ex Watt

Gossypium mustelinum Miers ex Watt is a native from Northeastern Brazil and belongs to the primary gene pool of the cultivated cotton. The unique places where the species was known to occur were visited to plan ex situ and in situ preservation. Two populations at Caicó became extinct, and only eleven individuals were found. At Jaguarari, although one population became extinct, a new one was localized with approximately 500 adult plants, where a fence avoided cattle feeding. The population from Macururé consisted of 28 plants protected from animals by thorns of Bromelia laciniosa Mart. ex Schult. f. Thirteen SSR primer pairs amplified 40 alleles, among which 30% were exclusive of one of the populations. The genetic differences between populations represented 58.3% of the total genetic variation observed. The high genetic distances are likely to be caused by geographical isolation as well as by the small number of individuals which contribute to new generations, and consequential genetic drift.     

河北38°N生态样带土壤有机碳特征

为阐明河北38°N生态样带土壤有机碳的空间分布特征,2011年9—10月,根据河北38°N带低山丘陵地区、山前平原地区和滨海低平原地区不同土地利用方式选取代表性样点,分层(0~10 cm、10~20 cm、20~40 cm、40~60 cm和60~100 cm)采集土壤样品,测定土壤有机碳含量。结果表明,河北38°N生态样带,低山丘陵地区土壤有机碳密度显著高于山前平原地区和滨海低平原地区,0~40 cm土层土壤有机碳密度分别为9.03 kg?m?2、4.26 kg?m?2和3.51 kg?m?2。低山丘陵地区与山前平原地区和滨海低平原地区土壤有机碳差异的部分原因是低山丘陵区灌丛土壤有机碳含量较高,明显提升了该地区的土壤有机碳水平。另外,低山丘陵地区林地和农田0~40 cm土层土壤有机碳含量也高于山前平原地区和滨海低平原地区;林地0~40 cm土层土壤有机碳含量在低山丘陵地区、山前平原地区和滨海低平原地区分别为19.45 g?kg?1、7.89 g?kg?1和7.55 g?kg?1,农田土壤有机碳含量在3个地区分别为7.70 g?kg?1、7.09 g?kg?1和6.00 g?kg?1。在整个生态样带上,土壤有机碳含量基本随土壤深度增加而不断减少,但各个地区不同土地利用方式减少的程度不同。低山丘陵地区0~40 cm土层内土壤有机碳含量变幅最大,其次为山前平原地区,滨海低平原地区变幅最小。低山丘陵地区灌丛土壤有机碳含量变化幅度最大,其次为林地,农田最小;山前平原地区土壤有机碳含量变化幅度农田略大于林地;滨海低平原地区土壤有机碳含量变化幅度林地最大,其次是荒地,农田最小。鉴于上述情况,从固碳和经济的双重角度考虑,提出以下建议:低山丘陵区大力发展林业产品和旅游业;山前平原区集中粮食生产,保证国家粮食安全;滨海地平原区加大土壤盐渍化改良,推广棉花种植。     

Sugar Cane Industry as a Source of Water Pollution – Case Study on the Situation in Ipojuca River, Pernambuco, Brazil

The Ipojuca river, a river in Northeast Brazil extending from west to east, is situated in the semiarid interior and rainy coastal zone of Pernambuco state. The river basin covers an area of 3,514 km², with a total river length of 215 km. The water flow regime is characterized by the annual change from dry to rainy season as well as periodically occurring dry cycles. Mean flow rates vary between 2 and 35 m³ s^?1. The dominant impacts on water quality of the river are domestic sewage input in the upper catchment and sugar cane cultivation and processing in the lower catchment. Long-term monitoring data used to demonstrate the impact of sewage discharge on the river’s self-purification capacity indicated a severe change to the worse in the lower course. One reason is the use of stillage (wastewater from cane processing) for fertilization and irrigation (fertigation). Pathways of contamination have been identified by evaluating cultivation and processing techniques of a bio-alcohol factory with annexed sugar cane cultivation. The river’s main ecological problems are water heating, acidification, increased turbidity, oxygen imbalance, and increased coliform bacteria levels. Precipitation-related wash-off and wash-out causes significant contamination within one to two days after rainfall. The increase in coliform bacteria is a consequence of secondary contamination. To determine the impact of the sugar cane industry on the river, the Brazilian bio-alcohol program must be subject to a critical evaluation. Environmentally friendly sugar cane cultivation methods need to be developed, and sugar cane factories must use waste-reducing technologies and water cycling processes in order to protect the region’s water resources.     

Ibuprofen Sorption to Coastal Plain Soils

Ibuprofen is commonly detected in onsite wastewater systems. Such onsite systems are abundant in coastal plain areas, globally. Coastal plain soils have unique mineralogy. Rapid subsurface transport may occur in coastal plain soils due to their characteristic permeable soils and seasonally high water tables. Laboratory batch sorption studies were conducted on Norfolk, Goldsboro, and Lynchburg, three archetypical coastal plain soils, with varying physicochemical properties, to evaluate ibuprofen sorption. Sorption distribution coefficients (K_D values) across all three soils ranged from 0.63 to 1.26 L kg^?1. Sorption of ibuprofen to Norfolk and Goldsboro soils was able to be modeled using a Freundlich isotherm; however, the Lynchburg soil, was not, likely due to soil heterogeneity. In general, sorption of ibuprofen was influenced by soil organic carbon content.     

Acidification and anadromous fish of Atlantic estuaries

The Hudson River Foundation convened a conference to evaluate evidence pertaining to the roles played by acid deposition and stream acidification in the decline of anadromous fish populations along the Atlantic coastal plain. The stimuli for the conference were that (1) some populations of Atlantic salmon, American shad, hickory shad, alewives, blueback herring and striped bass as well as a few species resident in coastal streams (yellow perch and white perch) are in a state of severe decline along portions of the east coast of North America; (2) several of these species have declined more or less simultaneously since about 1970; and (3) severe episodic pH depressions are observed in some streams of the Chesapeake Bay system. For example, the pH of Lyons Creek decreased from 7.0 to 5.9 in 1 hr during a rain event, returning to 7.0 a day later. After discussing several possible mechanisms for these observations, the conferees agreed that a combination of factors including stream and river acidification, toxic metals and organic compounds, eutrophication and overfishing appears to be contributing to the reduction in fish stocks. The essential point resulting from the conference is that the acid deposition hypotheses for stream acidification and declines of anadromous fish populations, a potential mechanism that has received very little attention heretofore, was shown to be viable for these coastal areas. Specific recommendations for research were agreed upon by the conferees.     

Conservation of the critically endangered Rumex rothschildianus as implied from AFLP diversity

Rumex rothschildianus (Polygonaceae) is a small dioecious annual endemic to the central coastal plain of Israel. This very rare sorrel is on the verge of global extinction, as its total gene pool consists of two surviving populations only: one small and the other relatively large and flourishing. The other ten populations of this species recorded during the 20th century (all in Israel) are now extinct. Amplified fragment length polymorphism (AFLP) markers were used to evaluate the population genetic structure of the two remaining populations. Genetic diversity in R. rothschildianus was H=0.17 with 48.9% polymorphic loci. Gene flow values suggest that the differentiation between the two populations is moderate (mean F_st=0.09). Considering these genetic data, two conservation management strategies should be applied: (1) Large scale reseeding in a neighbouring nature reserve to maintain the genetic diversity detected in this study. Seeds from diverse sources should be used for repeated reseedings in order to prevent the reintroduced populations from going through a genetic bottleneck or suffering genetic drift. (2) To maintain the genetic diversity in the two remaining wild populations, and to avoid risks such as possible outbreeding depression, only intrapopulation reinforcement should be considered. These populations should be carefully monitored and protected.     

Comparative Study of Common Bean (<Emphasis Type="Italic"> Phaseolus vulgaris</Emphasis>L.) Landraces Conserved <Emphasis Type="Italic">ex situ</Emphasis> in Genebanks and <Emphasis Type="Italic">in situ</Emphasis> by Farmers

Genetic diversity of populations stored ex situ or in situ can be altered due to the management practices they are subjected to. In this paper, we compare populations of two common bean (Phaseolus vulgaris L.) landraces grown on farms with material collected from the same farms and now kept in two ex situ collections (CIAT and REGEN) with the purpose to monitor any changes that have occurred due to ex situ conservation. The diversity was measured using seven bean microsatellite markers. Further phenotypic and developmental traits were registered in a field experiment. Compared with the in situ populations, the ex situ ones had a lower level of gene diversity and we suggest that this is due to the regeneration process. Most of the phenotypic traits did not differ significantly between ex situ and in situ populations, although for yield and 100-seed weight, the CIAT material showed significant lower values. We assume that these populations have gone through an adaptational change. Overall, the conservation ex situ has been successful in maintaining the majority of the adaptations found in the landraces studied, however, the probable loss of genetic diversity that we have observed, suggest that protocols for the regeneration process must be carefully worked out if the majority of alleles are to be preserved for the future. This study also highlights the complementarity of ex situ and in situ conservation methods in order to preserve landrace adaptations and to capture new, useful diversity generated in in situ populations.     

Traditional knowledge, genetic and morphological diversity in populations of Spondias tuberosa Arruda (Anacardiaceae)

Plant domestication is an evolutionary process whose artificial selection and management change the landscape, modeling plants to satisfy the human needs, affecting the phenotype component(s) of the species under manipulation. This study aimed at examining and comparing two rural communities: Malhada de Areia e Carão, municipally of Altinho, Pernambuco regarding the knowledge, perception of morphological variations (size fruit, flavor fruit, shape fruit, yield pulp and fruit color), morphological characteristics of preference at the time of collection; evaluation on the inter- and intrapopulation morphological differences of species and assessment of diversity, variability and local genetic structure of Spondias tuberosa populations under different management regimes based on the ISSR analysis. The results pointed to the maintenance of local genetic and morphological diversity, being it strongly related to the management practices of the species, especially the S. tuberosa tolerance in open areas for farming and pasture. Thus, it is emphasized the importance of this study in Brazil by being the first time that aspects related to management and perceived diversity, morphology and genetics of a highlighted perennial species from the semi-arid region of northeastern Brazil are evaluated from the perspective of domestication studies on its incipient status. Moreover, it provides interesting data that will contribute to the conservation strategies and breeding programs.     

Origin and geochemical evolution of saline groundwater in the Brisbane coastal plain,Australia

Fresh, brackish and saline groundwaters of variable acidity and redox potentials occur in a coastal floodplain area, north of the Brisbane River in Southeast Queensland, Australia. The complicated spatial and vertical distribution of these groundwaters, and their tendency towards a seawater chemistry, reflect that the local groundwater system has undergone repeated episodes of hydrological adjustments in response to Quaternary sea-level fluctuations and coastal landscape modifications. Since the last major Holocene transgression, topographic changes have permitted repetition of evaporative concentration, aeration and acidification processes in near-surface groundwaters. The surface and subsurface occurrences of gypsum, pyrite and jarosite minerals, in the Brisbane coastal plain, testify to the intrinsic relationship between sea-level and topographic variations, and hydrogeochemistry of the local groundwater system.     

Historical morphogenesis of the Turia River coastal flood plain in the Mediterranean littoral of Spain

The cross-referencing of sedimentological, stratigraphic, geoarchaeological and radiocarbon data enables us to establish the geomorphologic evolution of the Late Holocene coastal flood plain of the Turia River. The Holocene marine transgression formed a coastal barrier lagoon environment in the coastal plain. During the Late Holocene, increased sediments supplied to the low reach of the river promoted: (a): the progradation of deltaic coastal sandy ridges on the coastline and (b): the aggradation of the floodplain on top of the sedimentary sequence. Four phases are clearly recognised in the geoarchaeological record of the flood plain. (1): High magnitude flooding events (2800 BP to 3rd century BC). (2): Slow riverbed aggradation and progressive levee formation (low energy flood regime) in Roman times (2nd century BC to 5th century AD). (3): Swampy environmental processes (6th to 9th centuries). (4): Second high-magnitude flooding phase (11th century). The navigable channel of the Roman and early Islamic periods became a wide and shallow braided channel in Medieval times. These phases are correlated with others detected by researchers in many areas of the Mediterranean region and with global Holocene climate events.     

In situ evaluation of fruit yield and estimation of repeatability coefficient for major fruit traits of umbu tree [Spondias tuberosa (Anacardiaceae)] in the semi-arid region of Brazil

The umbu tree (Spondias tuberosa) is a xerophytic woody species endemic to the northeast of Brazil. The present work reports a three-year in situ evaluation of major yield components in a random set of trees in Petrolina city, Pernambuco State, Brazil and the application of repeatability coefficient in the context of genetic resources utilization. Five traits were assessed: total fruit yield per plant (FY); total number of fruits per plant (NF); average fruit weight (FW); average pulp weight (PW) and average fruit diameter (FD). The values observed for FY ranged from 4.2–184 kg with mean of 61.5 kg. The values for NF ranged from 257 to 12,981 fruits/tree with mean 3,993 fruits. For FW, the range was from 10.82–23.36 g with mean of 16.03 g. The values for PW ranged from 7 to 17 g with mean of 11.2 g, while FD values varied from 2.5 to 3.5 cm with mean of 3.0 cm. Six methods were employed to estimate repeatability coefficient (r) for all parameters. The r ranged from 0.68–0.76 for NF; 0.87–0.89 for FW; 0.65–0.75 for FY; 0.64–0.78 for PW and 0.70–0.84 for FD. Narrower ranges across methods were observed to r-values greater than 0.80, as observed for FW and FD. Three to four years of measurements will be necessary for FY, NF, and PW and one year for FW to obtain a precision of 90% to provide a reliable identification of individuals for in situ or ex situ conservation.     

Phytoextraction Potential of Atriplex Nummularia Plants under Nitrogen and Phosphate Fertilization

The soil areas affected by salts have increased in recent years. Searching intensively for management and recovery strategies should help minimize these problems. Studies related to the response of halophytes to fertilization can provide important information regarding the most adequate management for phytoremediation. The aim of this study was to evaluate dry matter production and sodium extraction capacity of atriplex plants, in response to nitrogen doses, with and without phosphorus application. The experiment was carried out in a greenhouse at the Federal Rural University of Pernambuco (UFRPE), in Recife, Pernambuco, Brazil and was set up in a randomized block design, with four replicates, in a 2 × 5 factorial scheme (0 and 134 mg dm^?3 of P and 0, 20, 40, 60, and 80 mg dm^?3 of N). The addition of nitrogen (N) and improved sodium (Na) uptake increased Na contents by 4.1, 3.6, and 1.8 times, for P0, and by 4.0, 8.4, and 2.1, for P134, in leaves, stems, and roots, respectively. There was a decrease in Na both in the saturation-paste extract and in the exchange complex with the increase in N in soil. N supply potentiates Na extraction by Atriplex nummularia, being a feasible technique to recover saline soils through phytoremediation.     

海河低平原不同地貌土壤盐分特征研究

以河流冲积扇、河流冲积扇与滨海平原过渡带、滨海平原3种主要地貌类型,分析了海河低平原区土壤盐分含量、盐基离子组成及电导率的变化规律。结果表明:河流冲积扇耕层虽明显脱盐,但由于底土含盐量高,仍存在土壤盐渍化的威胁,阴离子以Cl-和SO42-为主;相反,河流冲积扇与滨海平原过渡带、滨海平原表土含盐量较高,而底土含盐量较低,阴离子以Cl-为主;土壤盐分中阳离子含量以Na++K+为主,盐分组成主要的可溶性盐为NaCl,其次是Na2SO4和CaCl2。     

Multi-level characterization of perennial cotton (Gossypium hirsutum L. race marie-galante Hutch.) populations from the northeastern Brazil to the breeding and conservation of this germplasm

Genetic Resources and Crop Evolution - The remaining populations of perennial cotton (Gossypium hirsutum L. r. marie-galante Hutch.) that occur in northeastern Brazil are part of the primary gene...     

Increased CO2 emission and organic matter decomposition by leaf-cutting ant nests in a coastal environment

Leaf-cutting ants perform a vital role in the cycling of carbon and nutrients in tropical ecosystems. Nests have high levels of organic matter and refuse dumps host up to two times more soil micro-organisms than non-nest soil. The increased levels of organic matter in the soil of nests, however, can affect CO₂ emissions from soil and alter the balance of atmospheric CO₂. We aimed at assessing the effect of nests of the leaf-cutting ant Acromyrmex balzani on CO₂ emissions in a coastal area of Northeast Brazil. Results show that A. balzani nests emitted up to four times more CO₂ than the surrounding soil and emissions were positively correlated with soil moisture and soil organic matter (SOM) content. In addition, field experiments demonstrated that refuse material has a lower residence time than the leaf material brought to the colonies. Despite the high density of nests and high content of SOM compared to adjacent control soil, CO₂ emissions by A. balzani nests represent only 0.3% of the total CO₂ efflux by the studied ecosystem. Although these effluxes account for a relative small portion of the total soil CO₂ emission, they are still important for the understanding of C balance, especially when one considers the thousands of tons of CO₂ emitted each day, across entire Neotropical regions where leaf-cutting ants occur.     

Morphological Variation of Fruit in Mexican Populations of <Emphasis>Cocos nucifera</Emphasis> L. (Arecaceae) under <Emphasis Type="Italic">in situ</Emphasis> and <Emphasis Type="Italic">ex situ</Emphasis> Conditions

Morphological variation of the coconut fruit measured in situ has been used to estimate genetic diversity, and generate hypotheses about the evolutionary and geographical diffusion of coconut. Some authors have questioned the validity of this methodology due to the possibly high effect of the environment on the morphological characteristics of the fruit. The general aim of this study is to validate this methodology through: (1) characterizing the pattern of morphological variation of the fruit under homogeneous growing conditions ex situ; (2) comparing this pattern with those already reported in situ; (3) estimating the heritability values for the components of fruit in coconut. Results are also discussed in comparison with ex situ leaf variation and biochemical and molecular variation patterns previously studied. Principal components and discriminant analyses indicated that the characters that best differentiate groups are basically the same in situ and ex situ. Grouping patterns obtained with principal components and cluster analysis were similar for both growing conditions. They were also similar to the grouping pattern obtained with ex situ leaf characters. No significant differences were found in the variation coefficients of fruit characters between the same populations in situ and ex situ. Consistency was found between patterns of morphological variation of fruit ex situ and in situ, and those obtained using iso-enzymatic and molecular characteristics. The results are also consistent with hypotheses on the origin and diffusion of the germplasm introduced to Mexico. High values of heritability were found in nine characters. Weight and water percentage showed the highest values (0.88 and 0.883), with a strong correlation to the mass and the roundness of fruit and seed, suggesting that human selection of these characteristics led to the differentiation of domesticated populations. We conclude that morphological characterization of the coconut fruit in situ is useful to estimate its genetic variability because of its simplicity, speed and ease of application in the field and in remote areas.     

Paleosols of the southern coastal plain of Israel

Paleosols of the S coastal plain of Israel were studied in a characteristic sequence situated in the Ruhama badlands area. At the upper part of the sequence, there is a Loessial Arid Brown Soil (Calciorthids), characteristic of the mildly arid climate of the area. The soil has two calcic horizons and four clayey layers alternating with four calcareous layers which are beneath them. Physical, chemical, and magnetic‐susceptibility data and micromorphological evidence indicate that each clayey layer together with the calcareous layer beneath it forms a single pedogenic unit. These units are similar to modern Grumusolic soils (Xeric Paleargids or Xererthic Calciargids) that occur in the semiarid belt of the S coastal plain and develop on eolian‐dust parent material. The calcareous layers are in fact calcic horizons formed by leaching of the carbonates from the clayey layers and accumulated in the form of in situ carbonate nodules. The leaching of the carbonates is not complete; they were never completely leached in the past. This feature together with a typical brown color is also characteristic of the modern soils developed in the semiarid water regime of the area. The four superimposed paleosols represent four cycles. It is suggested that they were formed in two phases. During a dry environment, a short phase of rapid eolian‐dust accumulation prevailed, followed by a stable phase of soil development in a somewhat wetter climate. Dating by optically stimulated luminescence and previous dating by ¹⁴C in the area suggest that the upper two paleosol cycles belong to the Last Glacial period whereas the other two cycles are of an earlier age. The magnetic‐susceptibility values decrease with age and react different from temperate areas. Below the four cycles, two totally leached paleosols developed on sandy parent material occur. Both paleosols have a reversed magnetic polarity and are hence older than 780 ky BP. The upper one is a Brown Mediterranean soil, and the lower one is a Red Mediterranean soil. Thin‐section evidence suggests that they formed on terrestrial sand dunes.     

Anthropogenic and natural disturbance lead to differing patterns of gene flow in the Rocky Mountain tailed frog, Ascaphus montanus

Understanding the influence of habitat alteration on population structure and persistence is critical for effective conservation strategies. Timber harvest and wildfire are two of the most prevalent disturbances across temperate forests, yet the long-term effects of these two forces on population connectivity have rarely been studied. We studied populations of the Rocky Mountain tailed frog (Ascaphus montanus) across landscapes that have experienced either timber harvest or broad scale fires. Rocky Mountain tailed frogs generally require forested habitat, and are a species of concern in managed forests. We used landscape genetic techniques to test the explanatory power of alternative paths of connectivity across both burned and harvested forests and identified topographical and climatic variables that significantly influenced gene flow. We found that timber harvest and fire led to different patterns of genetic connectivity. Widespread terrestrial gene flow was maintained across previously burned areas and connectivity was primarily limited by solar radiation. In contrast, gene flow among populations in managed forests followed riparian corridors, presumably to avoid the loss of cover due to timber harvest. Gene flow along riparian corridors in Rocky Mountain tailed frogs differs from a population of the closely related coastal tailed frog (Ascaphus truei), for which gene flow appears to occur primarily over land. These results suggest management of Rocky Mountain tailed frogs should focus on maintaining riparian buffer zones, which may be less effective for the coastal species. Thus, consideration of landscape differences is essential even for conservation of closely related, morphologically similar species.     

东北平原西部近百年来生态环境退化机制分析

东北平原西部地区为草甸草原—草原过渡带,属典型的农牧交错区,生态环境脆弱,环境变化反映敏感。近百年来,本区的生态环境遭到严重破坏,大面积出现草原退化、沙化和盐碱化。通过对造成这一现象的自然和人文因素分析,结果表明,近百年尤其是近50年来,人口的大量增长和对水、土、生物资源的不合理利用,与其所处的地理环境及气候的变化（气温升高和降水波动较大等）,二者达成了"共振",导致了荒漠化的迅速发展,生态环境退化趋势显著。