The population size and structure of Cycas wadei were assessed along with habitat traits to update the current level of knowledge for conserving this Critically Endangered endemic species. Direct measurements of plant density and size, chemical analyses of soil and leaf tissue samples, and surveys of sympatric plants were conducted. The adult population was calculated at 5,051, indicating historical population size estimates were inaccurately low. Highest densities in forested fragments were 800 plants per hectare, with adults comprising 34% of the population. Density in grasslands was as high as 1,100 plants per hectare, with adults comprising 31% of the population. The dominant grass was Themeda gigantea (Cav.) Hackel, not Imperata as previously reported. The prediction that the soils were ultramafic was rejected but opinions that the soils were extremely infertile were confirmed by soil analyses. Leaf stoichiometry revealed the cycad plants were primarily limited by potassium availability and secondarily limited by phosphorus availability. Habitat conversion is the acute threat that must be monitored in the near future, and an attempt to moderate or halt this conversion is the greatest conservation need. Poaching is a second threat that has not been acute to date, but has the potential to become a greater threat if the remote habitat becomes more connected to national trade routes. Fire damage is the third major threat, and has the potential to become a greater threat if historical fire frequency is altered

We recently described characteristics of reproductive effort for the cycad Cycas micronesica on the island of Guam. The data were serendipitously recorded just prior to the devastating invasion of the armored scale Aulacaspis yasumatsui. This invasion decimated the cycad population and after six years of infestation no recruitment is occurring among the survivors. We describe various underlying mechanisms that may explain how this homopteran insect has eliminated host recruitment among categories including plant-pollinator mutualism disruptions, direct damage to reproductive structures, population level responses to declining plant health, and failures of seedlings to establish. Our pre-invasion data on reproductive effort will serve as the benchmark for quantifying how this alien pest is endangering the endemic cycad.