Volume 1, Issue 1, 2007

Forest soils offer great potential for bioremediation, including the sequestration of atmospheric carbon.  However, the benefits of bioremediation with soils often are difficult to quantify due to the lack of a clear market value associated with forest management induced changes in soil carbon.  An additional factor that confounds the valuation of carbon remediation benefits is the inherent spatial and temporal variation of the soil chemical and physical properties responsible for carbon sequestration.  Policy makers are attempting to draft criteria for valuing carbon, and it is expected that tradable emissions permits will be used to manage global climate change issues related to atmospheric carbon.  However, many policy makers are neglecting to include soil carbon sequestration in market accounting systems.  This oversight will result in suboptimal allocation of carbon credits, and efforts need to be taken to prevent the exclusion of soil carbon as an atmospheric carbon sink.  Case studies in the Missouri Ozarks and in the Arkansas Western Gulf Coastal Plain illustrate the challenges of using soil map units for estimating both soil and plant carbon fixation.  A failure to address the effects of variation in these systems will result in suboptimal valuation of the forest soil resource, so societal benefits from carbon sequestration will not be maximized. Full Article

 

Achene aerodynamics in species of Doellingeria, Eurybia, Oclemena, and Symphyotrichum.
Jerry G. Chmielewski and Steve R. Strain

Abstract
This study addresses dispersal potential among species of commonly co-occurring asters in the genera Doellingeria, Eurybia, Oclemena, and Symphyotrichum. The dissemination of wind-dispersed propagules is dependent upon launch height, the effectiveness of the pappus in keeping the propagule airborne, and the environmental conditions in effect at the time of their release from the inflorescence. As a factor affecting dispersal, launch height is generally of greater concern if obstructions are nearby, as these may impede the horizontal movement of propagules. Although variation in pappus bristle number, length, angle of attack, and mass exists, and in some instances is pronounced, these are not primarily responsible for the variation that exists in the terminal velocity of a propagule. Irrespective of the fact that the pappus bristles of the aster species are indeed the morphological agents facilitating dispersal, it would appear that achene mass is the single most important achene character dictating terminal velocity and thus the potential horizontal distance over which a propagule may be dispersed. As a generalization, it would appear that achenes of the weedier aster species, as a consequence of both plant height and comparatively lower values of terminal velocity, mostly attributable to comparatively lesser values for achene mass, have the potential to remain airborne longer and thus be dispersed further on average than achenes of the non-weedy aster species. Under natural conditions it is likely that few achenes actually do escape beyond the shadow of the parent plant, though this feature is not unique among the asters studied. Full Article



Bacterial Presence in Manufactured Soils
Maria V. Kalevitch, Valentine I. Kefeli

Abstract
Manufactured soil, also known as Fabricated Soil (FS), is a natural mixture of decaying substrates rich in aluminosilicate, carbon, nitrogen, phosphorus and potassium sources (complete composition and quantity cannot be disclosed at this time). This substrate is usually used for landscape rehabilitation, and is an excellent source and example of environmental remediation. Fabricated soils could be a solution to the problem of soil erosion.  This became a serious issue as all over the world millions of acres of soil are damaged. This study examines the use and application of FS in Western Pennsylvanian soils that were previously degraded by acid mining drainage. We are still trying to determine if fabricated soils are a long-term or short-term solution to the problem. After the exposure of FS into the natural habitat for the duration of three years, we evaluated bacterial activity in soil, as this is an important indicator of soil health.
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Sustainable Land Use and Urban Growth Management: Demand-Supply Factors and Strategic Planning Considerations      G. Schultink

Abstract

Public perceptions on the desirability of population and urban growth, its real impacts and the role of public policy, have changed dramatically since WW II. Global, national and local concerns increasing address the need to balance urban and rural growth, and uncontrolled development with its detrimental impacts. This includes efforts to preserve open space, food and fiber production, environmental quality and other aspects of quality of life. In the US, recent public surveys and practitioners increasingly identify land use conflicts and growth management as significant policy concerns. The core concern is the conversion of rural open space -- including prime agricultural land, woodlots and wetlands – to residential use, characterized by extensive and inefficient land use patterns. In Michigan, estimates indicate that land use conversions have exceeded 200 acres per day in the mid-1990s, and from 1960-90, urbanized growth areas have expanded at a rate 1.9 to 2.6 times faster than population growth, signifying a decreasing density of settlement. Current estimates put land conversion rates at about 10 acres (4 hectares) per hour. It is argued that a multitude of push and pull factors influence urban sprawl and should be analyzed with regard to public policy and land use planning. Push factors reflects declining urban quality of life and indirectly create demand for rural housing. In many cases, this is characterized by a flight from the central city to suburban areas, followed by migration from traditional suburbia to lower density subdivisions and extensive rural residential areas. This “leapfrog” effect represents an important new phenomenon in open space conversion, directly subsidized by financing the inefficient expansion of infrastructure.  Various growth management tools and strategies are discussed. The notion of growth balance is introduced as a policy tool to regulate the demand and supply of land subject to conversion and identify conditions that promote responsible urban-residential expansion. It is further argued that state-endorsed, comprehensive and regional decision-making approaches are needed to explore future expansion alternatives and promote growth patterns that are more economically viable and environmentally sustainable. Full Article

Towards Cytoplasmic Male Sterility in Cultivated Tomato
Pravda K. Stoeva-Popova, Dwight Dimaculangan, Mariana Radkova, Zlatka Vulkova
 

Abstract

Cytoplasmic male sterility (CMS) is a phenomenon observed in more than 150 plant species. CMS is maternally inherited and is based on changes in the mitochondrial chromosomal DNA structure and gene expression as influenced by nuclear genes. CMS is an important tool for hybrid seed production. Presently, a CMS system does not exist for the cultivated tomato, Lycoperison esculentum. The focus of this review is to summarize our studies of the unique Lycopersicon CMS line produced from the late backcrosses of the cross L. peruvianum (pistillate parent) and L. pennellii (recurrent pollinating parent) and its hybrids with L. esculentum.  On the background of the advancements in the research of other plant CMS systems, we discuss our results and consider the practical approaches for the development of CMS system in the cultivated tomato. Full Article
 

Pesticide Residues in Soil and Water from Four Cotton Growing Areas of Mali, West Africa
Safiatou Berthe Dem,Jean M. Cobb,Donald E. Mullins
 

Abstract

Pesticide residues were determined in soil and water collected from four cotton-producing areas of Mali, West Africa. Pesticides were detected in 77% of the soil samples and included p,p-DDT and its breakdown products, endosulfan I and II, endosulfan sulfate; and profenofos. According to 24 farmers surveyed in the study area, DDT was not used in their fields during the past ten years. Endosulfan II, the most commonly detected pesticide, constituted 65% of the detections with a maximum concentration of 37 ng/g. Residues detected in soil samples were below our quantification limit in the newer cotton-producing region of Kita and intermediate region of San. Residues were detected at reportable levels in Koutiala (older) and Sikasso (intermediate) cotton producing areas. Eight pesticides were detected in water samples: lindane, endosulfan I, endosulfan II, endosulfan sulfate, dieldrin, p,p-DDD, p,p-DDE, and atrazine. All detected pesticides in water had concentrations below our established quantification limit except for atrazine. In spite of low concentration levels, pesticides in these water sources are of great concern because they are used for human and animal consumption. Similarly, plant uptake of pesticides poses health risks to domestic livestock that forage on crop stubble and to consumers of food products from these animals. Further studies in the cotton growing areas of Mali are needed to monitor pesticide residues in soils, water, and living organisms. Full Article


 

Genetic Analysis of Soybean Plant Height, Hypocotyl and Internode Lengths
Allen Alcivar,Josie Jacobson, Jennifer Rainho, Khalid Meksem  David A. Lightfoot, My Abdelmajid Kassem

Abstract

Toxicity of Metal-enriched Black Shale-draining Surface Waters to Ceriodaphnia dubia, and Pimephales promelas    George M. Ogendi,Robyn E. Hannigan, Jerry L. Farris

Abstract

Copper Tolerance to Germination in Mesquite, a Potential Tree Species for Restoring Mined-lands in Oman    Reginald Victor, Avin Pillay,Sakina Al-Minji

Prosopis juliflora (Sw.) DC. (Fabaceae - Mimosoideae), commonly known as Ghaf Bahri or Velvet Mesquite, an introduced exotic tree species in Oman is considered as a noxious weed. Efforts to contain this tree are labor intensive and expensive. Therefore, an efficient use of this species for socioeconomic and environmental benefits in Oman must be considered seriously. This study initiates a feasibility investigation of using P. juliflora for the restoration of copper mined lands in Oman by evaluating copper tolerance to seed germination in the laboratory.

Continuous exposure experiments showed the ability of P. juliflora to germinate in copper concentrations ranging from 10-1280 ppm. The adverse effect of copper on percentage seed germination was more pronounced in the first two days. From 3-8 days, P. juliflora showed a remarkable ability for recovery. Seedling morphology showed the adverse effect of copper exposure from 80 –1280 ppm and seedling height decreased exponentially with the increase in copper concentrations. The relationship between copper concentrations and the average

copper content of the seedlings fits a non-linear power model. Thus the germinating seeds of P. juliflora also seem to serve as a sink for copper in contaminated soils. These ex situ germination experiments suggest that P.juliflora is a suitable species for use in the restoration of copper mined-lands. Using known facts, identifying both ecosystem and socioeconomic factors, a SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis is provided here to assist in recommending management strategies and policy decisions. Full Article

Impact of temperature and defoliation (simulated grazing) on soil respiration of pasture grass (Cenchrus ciliaris L.) in a controlled experiment
Kamaljit Kaur,Rajesh K Jalota,David J. Midmore


Abstract

A controlled experiment was conducted on Cenchrus ciliaris L. grass (exotic to Australia) commonly grown in Queensland pastures to investigate the impact of defoliation (simulated grazing), temperature and soil moisture on total soil respiration, and to isolate different components of total soil respiration i.e. the root, root free soil and rhizosphere respiration. The six types of treatments i.e. control (soil only without grass (C1)), control with grass but no defoliation (C2) grown for 9 months, non-defoliated treatments with grass grown for 4 months (D0), and three defoliation treatments (grass defoliated once, D1; twice, D2; and thrice, D3 during growth) were maintained over 9 months. Our results suggested that defoliation had no effect on total soil respiration. However, soil temperature accounted for significant changes in total soil respiration across all the defoliation and C2 treatments but not in D0, and the greatest change in soil respiration in response to temperature was noted at the third stage of defoliation, suggesting that defoliation increased the sensitivity of soil respiration to temperature. Root respiration was significantly (P <0.05) related to root biomass and greater root biomass contributed mainly to increased rate of total soil respiration. The greater sensitivity of total soil respiration to temperature in D1, D2, D3 and C2 treatments and the greater contribution of root respiration in total soil respiration suggests that the root respiration, rather than the total soil respiration, is likely to be more sensitive to change in temperature. With rising ambient temperature and consequently soil temperature, soil CO_{2 emissions may increase in a pasture with greater root biomass than that with lesser root biomass. Full Article}