Why high seed densities within buried mesh bags may overestimate depletion rates of soil seed banks

1. Estimates of seed bank depletion rates are essential for modelling and management of plant populations. The seed bag burial method is often used to measure seed mortality in the soil. However, the density of seeds within seed bags is higher than densities in natural seed banks, which may elevate levels of pathogens and influence seed mortality. The aim of this study was to quantify the effects of fungi and seed density within buried mesh bags on the mortality of seeds. Striga hermonthica was chosen as the study species because it has been widely studied but different methods for measuring seed mortality in the soil have yielded contradictory estimates. 2. Seed bags were buried in soil and exhumed at regular time intervals to monitor mortality of the seeds in three field experiments during two rainy seasons. The effect of fungal activity on seed mortality was evaluated in a fungi exclusion experiment. Differences in seed-to-seed interaction were obtained by using two and four densities within the seed bags in consecutive years. Densities were created by mixing 1000 seeds with 0, 10, 100 or 1000 g of coarse sand. 3. The mortality rate was significantly lower when fungi were excluded, indicating the possible role of pathogenic fungi. 4. Decreasing the density of seeds in bags significantly reduced seed mortality, most probably because of decreased seed-to-seed contamination by pathogenic fungi. 5. Synthesis and applications. Models of plant populations in general and annual weeds in particular often use values from the literature for seed bank depletion rates. These depletion rates have often been estimated by the seed bag burial method, yet seed density within seed bags may be unrealistically high. Consequently, estimates of seed mortality rates may be too high because of an overestimation of the effects of soil or seed-borne pathogens. Species that have been classified from such studies as having short-lived seed banks may need to be re-assessed using realistic densities either within seed bags or otherwise. Similarly, models of seed bank dynamics based on such overestimated depletion rates may lead to incorrect conclusions regarding the seed banks and, perhaps, the management of weeds and rare species.

The economic consequences of mortgage debt

Unsurprisingly, a great deal of attention has been paid to the economic consequences of the credit crunch. However, this paper shows that the credit crunch was preceded by a strong build-up of mortgage debt internationally, which, in the long run, could turn out to be more significant than the credit crunch itself. Indeed, the debt build-up suggests that the credit crunch is more likely to reoccur, because highly-indebted households have weaker buffers to withstand unexpected shocks to their incomes or to interest rates. The paper presents a model that can explain the debt build-up and changes to the distribution of debt between existing owners and first-time buyers, which hinders access to home-ownership for the latter, even amongst those households who would be considered as credit-worthy.

European CMBS pricing: bond, mortgage and real estate characteristics

The recent global economic crisis is often associated with the development and pricing of mortgage-backed securities (i.e. MBSs) and underlying products (i.e. sub-prime mortgages). This work uses a rich database of MBS issues and represents the first attempt to price commercial MBSs (i.e. CMBSs) in the European market. Our results are consistent with research carried out in the US market and we find that bond-, mortgage-, real estate-related and multinational characteristics show different degrees of significance in explaining European CMBS spreads at issuance. Multiple linear regression analysis using a databank of CMBSs issued between 1997 and 2007 indicates a strong relationship with bond-related factors, followed by real estate and mortgage market conditions. We also find that multinational factors are significant, with country of issuance, collateral location and access to more liquid markets all being important in explaining the cost of secured funding for real estate companies. As floater coupon tranches tend to be riskier and exhibit higher spreads, we also estimate a model using this sub-set of data and results hold, hence reinforcing our findings. Finally, we estimate our model for both tranches A and B and find that real estate factors become relatively more important for the riskier investment products.

Income multiples and mortgage repossession in the UK

This paper presents the findings of the study that examines how income multiples for mortgage loan associates with home repossession using the data of the Council of Mortgage Lenders (CML). It employs a statistical measure for improving regression efficiency with conditioning information in the form of lagged instrument to unravel the pattern of association evident from the data. Based on the data, the study investigates what level of income multiples is optimum – that is the income multiple that minimises home repossession. A sensitivity analysis was undertaken to show how home repossession responds to changes in income multiples. For each of the analytical tasks, the study compares the aggregate market, first-time-buyers, and home movers.

Contributory negligence involving overseas European banks in property valuation negligence cases in the UK

This paper examines the phenomenon of cross-border property lending and examines a number of issues regarding lending procedures and decision making processes in the context of the relationship between lender and professional advisor. It commences by placing these procedures and processes in the context of the development of cross border European property investment and finance. The UK has been a popular destination for overseas investors and lenders over the last decade and is therefore used as a case study to examine the additional institutional risk that overseas lenders may face when operating outside of their own country and obtaining advice from home professionals. The UK market was the subject of a boom period during the late 1980s, followed by a recession in the early 1990s. The losses triggered a number of professional negligence actions by lenders against valuers. These include a number of overseas lenders mainly from Europe and these cases have been examined for any particular features which, coupled with other data gained from overseas lenders as part of an interview survey, could be used to isolate any significant problems for European lenders in overseas markets. The research identified a lack of clarity in roles and relationships between lender and advisor, difficulties in communications both internally and between overseas branches and headquarters and failures in provision and interpretation of advice. The paper concludes by identifying the issues which may need to be addressed generally by lenders and their advisors, when the lenders are operating in overseas markets.

Investigation into the adoption intention of social CRM in Saudi banks

The growth of Web 2.0 generation will have influence on developing strong relationships with customers. Even though Web 2.0 technologies and applications have gained significant attention recently by academics and practitioners, research into its potential integration with CRM system remains a poorly investigated subject. This paper aims to investigate the adoption intention of social CRM system, focusing on Saudi banks. A conceptual model was proposed based on technology organisation and environment (TOE) framework. A qualitative approach was applied to validate the research model. The finding suggests that technology infrastructure, and competitive pressures tend to be the most influential drivers to adopt social CRM. In contrast, the limited number of IT experts, security concerns, and organisational structure were found to negatively affect social CRM adoption intention.