Monospecific mangrove reforestation changes relationship between benthic mollusc diversity and biomass: Implication for coastal wetland management

Anthropogenic causes are overtaking natural factors to reshape patterns of biodiversity and ecosystem functioning. Mangrove reforestation aimed at reversing losses of mangroves has been conducted worldwide for several decades. However, how reforestation influences the link between ecological processes that shape community diversity and the consequent effects on ecosystem functions such as biomass production is less well known. Here we used data collected before and after mangrove planting to examine the effects of reforestation on molluscan species richness and biomass production by testing the changes in species richness, compositional similarities, distance-decay effects (community similarity decreases with increasing geographical distance) in metacommunity across a regional scale of 480 km (23-27 °N) in southeast Chinese coasts. Additionally, we further detected the impact of landscape configuration caused by different intensities of reforestation on the mollusc community. After the mangrove reforestation, mollusc species richness and biomass increased significantly. The increases in species richness and biomass of mollusc community were mediated by reducing distance-decay effect, indicating an increase in relationship strength between species richness and biomass might be associated with a decrease in distance-decay effect with rising mangrove habitat. We highlight the importance of considering the effects of anthropogenic changes on the relationship between biodiversity and ecosystem functioning. Quantifying the distance-decay effect of these influences enables management decisions about coastal restoration to be based upon ecological mechanisms rather than wishful thinking or superficial appearance.

Spatial arrangement of the heart structure: Application of second-order stereology in diabetic rats

The present study explored three-dimensional spatial arrangements of the cardiomyocytes and microvessels within the heart of rats and evaluated the arrangement for differences after diabetes using second-order stereology. Isector method was applied to obtain isotropic uniform random sections of the heart. The pair correlation g(r) and cross-correlation functions were estimated by counting dipole probes (with length of 3.57 μm) superimposed on histological sections of the heart. The co-variograms indicated that the curve of g(r) for the cardiomyocyte showed a gap between cardiomyocytes at r=21-25 μm in the control rats and a wider gap at r=18-50 μm in diabetic hearts. Estimates of g(r) for the vessels also showed a wider gap (at r=25-39 μm) in diabetic hearts compared to the control rats (r=25-32 μm). These indicate a negative correlation (repulsion) between the cardiomyocytes and microvessels in the diabetic hearts. Evaluation of the cross-correlation function of the cardiomyocytes and microvessels showed that at 32-36 μm, both structures had a negative correlation in the control group, but not in the diabetic rats.

CONCLUSION

Dissociation of the cardiomyocytes at some places can be seen in diabetic heart. This can be seen also in microvessels. Neither cardiomyocytes nor microvessels are arranged normally after diabetes.