Not exactly an unexpected finding (the article is dealing with long-term studies, eg, effects of climate change over decades on a population). I suppose it would probably hold true for animals as well, except for large and / or charismatic species.
" ‘Our findings should serve as a call for the [scientific community] to target these understudied regions and types of plants. Understanding plant demography can guide conservation when environments are rapidly changing’, says co-author Johan Dahlgren, also from the Department of Biology, University of Southern Denmark."