Responses of global plant diversity capacity to changes in carbon dioxide concentration and climate

Abstract

We model plant species diversity globally by country to show that future plant diversity capacity has a strong dependence on changing climate and carbon dioxide concentration. CO2 increase, through its impact on net primary production and warming is predicted to increase regional diversity capacity, while warming with constant CO2 leads to decreases in diversity capacity. Increased CO2 concentrations are unlikely to counter projected extinctions of endemic species, shown in earlier studies to be more strongly dependent on changing land use patterns than climate per se. Model predictions were tested against (1) contemporary observations of tree species diversity in different biomes, (2) an independent global map of contemporary species diversity and (3) time sequences of plant naturalisation for different locations. Good agreements between model, observations and naturalisation patterns support the suggestion that future diversity capacity increases are likely to be filled from a 'cosmopolitan weed pool' for which migration appears to be an insignificant barrier.

Climate change and elevational diversity capacity: do weedy species take up the slack?

“…The isolation of the island means that no new species have colonized naturally, and the short period has precluded speciation, thus explaining the absence of a change in richness among years, in keeping with previous predictions [5]. Nonetheless, a few species have vacated the lower elevations, although the exact reasons for this change remain poorly understood [14].…”

“…Species range shifts have also been forecast to lead to changes in local and regional diversity [4]. Among these forecasts is the idea that in areas that are not water-limited, diversity capacity will increase with increasing resource capacity, such as net primary productivity [5,6]. However, owing to relatively slow rates of speciation and movement of most species, this capacity (e.g.…”

“…However, owing to relatively slow rates of speciation and movement of most species, this capacity (e.g. for plant species richness) will typically be taken up by cosmopolitan, weedy species that are rapidly moved around by humans [5]. Documenting weedy take up of diversity capacity in most of these systems is likely to be confounded by human development and disturbance, which also promote the establishment of weedy species [7], and are increasing, even in regions that are already developed [8,9].…”

It is getting hotter in here: determining and projecting the impacts of global environmental change on drylands

“…This is because of the complex interactions and contrasting effects of predicted changes in different global change drivers. For instance, while the expected reductions in water availability will likely exacerbate water stress and reduce productivity of dryland vegetation [43][44][45], increases in [CO 2 ] may improve the water use efficiency (WUE) of plants, and thus ameliorate and potentially counterbalance negative effects of reduced soil moisture [46][47][48]. However, improvements in WUE may not suffice to compensate negative effects on soil moisture of increased evapotranspiration and reduced rainfall scenarios, particularly when feedbacks between elevated CO 2 , water availability and vegetation are taken into account [49].…”

On the Statistical Mechanics of Alien Species Distribution

“…Biologically, it represents some resource that may be related to global net primary productivity and it is an instance of the process of 'biotic resistance' and the fundamental regulation of community diversity [17][18][19][20][21][22]. CO 2 has been shown elsewhere to enhance net primary productivity above the general action of climate change (temperature and water availability) [23], suggesting that it may be the fundamental factor responsible for the ongoing rate of species naturalisations currently being observed throughout the globe [24][25][26][27][28].…”