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Nonanalogous climates (NACs), climates without modern analogs on Earth, challenge our understanding of eco-evolutionary processes that shape global biodiversity, particularly because of their propensity to promote novel ecosystems. However, NAC studies are generally inadequate and partial. Specifically, systematic comparisons between the future and the past are generally lacking, and hydraulic NACs tend to be underemphasized. In the present study, by adopting a frequency distribution-based method that facilitates the procedures of contributions parsing and conducting multiple comparisons, we provide a global overview of multidimensional NACs for both the past and the future within a unified framework. We show that NACs are globally prevalent, covering roughly half of the land area across the time-periods under investigation, and have a high degree of spatial structure. Patterns of NACs differ dramatically between the past and the future. Hydraulic NACs are more complex both in spatial patterns and in major contributions of variables than are thermal NACs. However, hydraulic NACs are more predictable than originally thought. Generally, hydraulic NACs in the future (2100 AD) exhibit comparable predictability to thermal NACs in the last glacial maximum (LGM) (21k BP). Identifying these NAC patterns has potential implications on climate-adaptive managements and preparing in advance to possibly frequent novel ecosystems. However, a learning-from-the-past strategy might be of limited utility for management under present circumstances., (© 2018 John Wiley & Sons Ltd.)

Predicting species range shifts in response to climatic change is a central aspect of global change studies. An ever growing number of species have been modeled using a variety of species distribution models (SDMs). However, quantitative studies of the characteristics of range shifts are rare, predictions of range changes are hard to interpret, analyze and summarize, and comparisons between the various models are difficult to make when the number of species modeled is large. Maxent was used to model the distribution of 12 Abies spp. in China under current and possible future climate conditions. Two fuzzy set defined indices, range increment index (I) and range overlapping index (O), were used to quantify range shifts of the chosen species. Correlation analyses were used to test the relationships between these indices and species distribution characteristics. Our results show that Abies spp. range increments (I) were highly correlated with longitude, latitude, and mean roughness of their current distributions. Species overlapping (O) was moderately, or not, correlated with these parameters. Neither range increments nor overlapping showed any correlation with species prevalence. These fuzzy sets defined indices provide ideal measures of species range shifts because they are stable and threshold-free. They are reliable indices that allow large numbers of species to be described, modeled, and compared on a variety of taxonomic levels.

Simple Summary: Freshwater ecosystems are embedded in terrestrial ecosystems to form an integral whole. In the context of global climate change, freshwater ecosystems may be irreversibly negatively affected; thus, aquatic organisms dependent on freshwater ecosystems are severely affected. However, terrestrial life may also experience unexpected crises due to the collapse of freshwater ecosystems, and we know very little about the relationship between terrestrial life and freshwater ecosystems. Therefore, we conducted our research on the Tibetan Plateau, an area with a dense distribution of lakes. We analyzed the relationship between the number of Tibetan antelopes (an ungulate mammal distributed in the region) and the number of lakes, and the distribution of the terrain and vegetation around the lake. Our results indicated that a greater abundance of Tibetan antelopes was associated with larger lakes, flatter terrain, and proximity to lakes, which may all be factors that affect the survival of this species. Our study suggests that lakes may provide a better habitat for ungulates in such a fragile ecosystem, including a different predation risk and more food resources, and this also provides a new research idea for the study of multi-species coexistence on the Tibetan Plateau. The influence of freshwater ecosystems on terrestrial taxa in high-altitude regions with challenging access, such as the Tibetan Plateau, remains inadequately understood. This knowledge gap is particularly significant due to the fragility of these ecosystems, characterized by low primary productivity. Ungulates, in particular, may exhibit high sensitivity to even minor alterations in plant availability, potentially stemming from global climate change. Consequently, the investigation of these ecosystems may offer valuable insights into addressing future challenges posed by climate change. Here, to fill this knowledge gap, we explore the relationship between lakes and Tibetan antelopes in an even more vulnerable region, the Tibetan Plateau. We found that the Tibetan antelope population was higher in areas with larger lakes, and where the terrain near the lakes was flatter. At the same time, vegetation cover and plant diversity were higher near the lake compared to areas farther away from the lake. This phenomenon can be elucidated by the fact that lakes offer Tibetan antelopes a richer food supply and reduced predation risk. Our study provides new perspectives for researchers to explore the cross-ecosystem impacts of climate change. [ABSTRACT FROM AUTHOR]

It is inevitable that tree species will undergo considerable range shifts in response to anthropogenic induced climate change, even in the near future. Species Distribution Models (SDMs) are valuable tools in exploring general temporal trends and spatial patterns of potential range shifts. Understanding projections to future climate for tree species will facilitate policy making in forestry. Comparative studies for a large number of tree species require the availability of suitable and standardized indices. A crucial limitation when deriving such indices is the threshold problem in defining ranges, which has made interspecies comparison problematic until now. Here we propose a set of threshold-free indices, which measure range explosion (I), overlapping (O), and range center movement in three dimensions (Dx, Dy, Dz), based on fuzzy set theory (Fuzzy Set based Potential Range Shift Index, F-PRS Index). A graphical tool (PRS_Chart) was developed to visualize these indices. This technique was then applied to 46 Pinaceae species that are widely distributed and partly common in China. The spatial patterns of the modeling results were then statistically tested for significance. Results showed that range overlap was generally low; no trends in range size changes and longitudinal movements could be found, but northward and poleward movement trends were highly significant. Although range shifts seemed to exhibit huge interspecies variation, they were very consistent for certain climate change scenarios. Comparing the IPCC scenarios, we found that scenario A1B would lead to a larger extent of range shifts (less overlapping and more latitudinal movement) than the A2 and the B1 scenarios. It is expected that the newly developed standardized indices and the respective graphical tool will facilitate studies on PRS's for other tree species groups that are important in forestry as well, and thus support climate adaptive forest management. [ABSTRACT FROM AUTHOR]