Impacts of Biodiversity Loss Escalate Through Time as Redundancy Fades

Abstract

Plant diversity generally promotes biomass production, but how the shape of the response curve changes with time remains unclear. This is a critical knowledge gap because the shape of this relationship indicates the extent to which loss of the first few species will influence biomass production. Using two long-term (≥13 years) biodiversity experiments, we show that the effects of diversity on biomass productivity increased and became less saturating over time. Our analyses suggest that effects of diversity-dependent ecosystem feedbacks and interspecific complementarity accumulate over time, causing high-diversity species combinations that appeared functionally redundant during early years to become more functionally unique through time. Consequently, simplification of diverse ecosystems will likely have greater negative impacts on ecosystem functioning than has been suggested by short-term experiments.

In a long-term experimental demography study, excluding ungulates reversed invader's explosive population growth rate and restored natives

“…If the results of our experiment apply generally, then reducing ungulate numbers where they are overabundant will be key in curbing invasion success in forest and rangelands worldwide. These habitats are in particular need of policy and management practice reform, because their ecosystem functions are predicted to further decline over time as community diversity degenerates (58) and functional redundancy is lost (59). Finally, our findings underscore the need for comanagement strategies for ungulates and invasive plants to maintain functional native-invasive interactions that preserve biodiversity.…”

Biodiversity and ecosystem functioning in dynamic landscapes

“…The effects of biodiversity loss are rapidly seen when multiple functions are monitored over longer periods of time and across multiple local habitats [5], which reflects the ability of more diverse communities to stabilize processes across multiple environmental conditions [16,17]. Consequently, biodiversity effects in BEF experiments increase over time [6] with increasing resource use complementarity. This rather broad consensus on BEF experiment results is reflected by increasing awareness that changing biodiversity can affect ecosystem processes with a magnitude that is similar to other known impacts on ecosystems, such as eutrophication, disturbances or herbivory [18,19].…”

“…Generalizing over several hundred studies, there is clear evidence that the loss of biodiversity from a certain trophic group of species results in their reduced biomass production, associated with reduced efficiency of resource capture [1][2][3]. This relationship has been primarily observed in communities of autotrophs such as plants [4][5][6][7], but also holds in consumers of plant or animal resources [8][9][10] and decomposers feeding on dead organic material [11,12]. In fact, the loss of biodiversity across trophic levels has been predicted to show even stronger effects owing to the strong connection between consumer -resource energy fluxes and ecosystem processes [2,13,14].…”

Biodiversity acts as insurance of productivity of bacterial communities under abiotic perturbations

“…The role of biodiversity is crucial for ecosystem functioning (Hooper et al, 2005;Cardinale et al, 2006;Loreau, 2010;Reich et al, 2012) because diverse communities may use available resources more efficiently and maintain the ecosystem functioning under environmental uncertainty. The importance of biodiversity becomes more evident under environmental fluctuations where it may act as ecological insurance for maintaining the ecosystem functioning (Yachi and Loreau, 1999;Tilman et al, 2006;Loreau and de Mazancourt, 2013).…”