4 research outputs found
All Is Not Loss: Plant Biodiversity in the Anthropocene
Anthropogenic global changes in biodiversity are generally portrayed in terms of massive native species losses or invasions caused by recent human disturbance. Yet these biodiversity changes and others caused directly by human populations and their use of land tend to co-occur as long-term biodiversity change processes in the Anthropocene. Here we explore contemporary anthropogenic global patterns in vascular plant species richness at regional landscape scales by combining spatially explicit models and estimates for native species loss together with gains in exotics caused by species invasions and the introduction of agricultural domesticates and ornamental exotic plants. The patterns thus derived confirm that while native losses are likely significant across at least half of Earth's ice-free land, model predictions indicate that plant species richness has increased overall in most regional landscapes, mostly because species invasions tend to exceed native losses. While global observing systems and models that integrate anthropogenic species loss, introduction and invasion at regional landscape scales remain at an early stage of development, integrating predictions from existing models within a single assessment confirms their vast global extent and significance while revealing novel patterns and their potential drivers. Effective global stewardship of plant biodiversity in the Anthropocene will require integrated frameworks for observing, modeling and forecasting the different forms of anthropogenic biodiversity change processes at regional landscape scales, towards conserving biodiversity within the novel plant communities created and sustained by human systems
Global relationships between (A) anthropogenic species loss (<i>ASL</i>) and increase (<i>ASI</i>), (B) anthropogenic (<i>ASR</i>) and native (<i>N</i>) species richness, (C) <i>N</i> and population density, (D) Habitat loss (<i>HL</i>; fraction of habitat lost to land use) and population density, (E) <i>ASL</i> and population density and (F) <i>ASI</i> and population density, (G) <i>ASL</i> and <i>HL</i>, and (H) <i>ASI</i> and <i>HL</i>.
<p>Points represent regional landscape cells, colored by anthrome class. Thick black lines are regressions with <i>R</i><sup>2</sup> at lower right; thin dashed black lines are upper and lower regression models from sensitivity analysis. Thick dashed black lines indicate <i>X</i> = <i>Y</i> in (A) and (B) and smoothed curve fit to data in (I).</p
Global maps of (A) Native species richness (<i>N</i>), (B) Anthropogenic species richness (<i>ASR</i>), (C) Anthropogenic species richness (<i>ASR</i>) relative to <i>N</i>, (D) total anthropogenic species loss (<i>ASL</i>) + anthropogenic species increase (<i>ASI</i>) relative to <i>N</i>, (E) <i>ASL</i> relative to <i>N</i>, (F) <i>ASI</i> relative to <i>N</i>, (G) <i>ASL</i>, (H) <i>ASI</i>, (I) exotic species invasions (<i>IS</i>), (J) <i>IS</i> relative to <i>N</i>.
<p>All maps in Eckert IV global equal area projection.</p