Finally, the intra-annual population cycle seemed to influence the relation between species and habitat structure and, possibly, inter-specific competition for resources.
On drier sites where under-canopy vegetation persists into mid-rotation, inter-specific competition for water can also occur with resulting impacts on tree growth (Richardson et al. 2002), as could inter-specific competition for limited nutrients, particularly on sites with nutrient deficiencies (Albaugh et al. 2013).
These results are highly suggestive of intra-specific competition for resources: competition for resources decreased with increasing NND and increased with increasing LNS at the 0.1 m spatial scale during fruit maturation.
Whilst the specific threats vary among species, problems such as introduced predators, loss of suitable nesting habitat and inter- and intra-specific competition for nest sites are common to many situations.
However the higher values for all growth parameters and yield attributes of Solanum khasianum outside tree canopy suggests that the plants grown outside tree canopy as sole crop has better opportunities to reap more solar energy for photosynthetic activity, less intra-specific competition for critical resources like water, nutrients, and photo synthetically active radiation.
Although their efficacy depended on the species and the island considered, artificial burrows provided more stable and persistent breeding habitat (12-years persistence: 80% vs. 72%), allowed the recruitment of new breeders and good reproductive success (49 76%), and probably reduced inter-specific competition for nesting cavities, across the two islands.
The ready supply of organic material to the benthos may also decrease inter-specific competition for the food resource and hence reduce the potential for fine-scale niche separation [64].
The majority of biological populations experience some level of density-dependent population growth that is a function of intra-specific competition for available food energy [16], although other factors, such as predation and abiotic stressors, are also involved [17].
We contend, therefore, that competition between the species used in this study is reduced, at least in part, because of inter-specific differences in feeding and digestion rates [37], although we cannot discount the importance of the occupation of different sediment depth strata as a further mechanism of reducing inter-specific competition for space and resources [23].
These results suggest that density regulation in this system may operate when populations are at or near carrying capacity – a state where intra- and inter-specific competition for resources and intra-specific competition for mates is likely to be highest.
