Old-growth forest is what giant pandas really need

Habitat use by giant pandas Ailuropoda melanoleuca in the Wanglang Nature Reserve, Sichuan, China

Background

To better understand the ecological requirements of the giant panda Ailuropoda melanoleuca in the wild, field surveys were carried out at both the microhabitat scale and foraging site scale in Wanglang National Nature Reserve, Sichuan, China.

Results

The results indicated that (1) at the microhabitat scale, giant pandas usually occupied habitats with a high fallen-log density, lower shrub density, and bamboo coverage of 50% to 75%; (2) at the foraging site scale, pandas usually used sites with higher bamboo densities and taller and larger-diameter bamboo; and (3) giant pandas may abandon plots when the proportion of young bamboo decreases below average in the environment.

Conclusions

The availability of young bamboo is an important driving force in habitat selection by giant pandas, which could provide important reference for the conservation of giant pandas and their habitats.

Can conservation of single surrogate species protect co-occurring species?

Conservation of surrogate species is expected to benefit co-occurring species with similar distributions that share the same habitat, yet the usefulness of this approach to protect nontarget species has been extensively challenged. In this study, we aimed to assess whether co-occurring species could be afforded protection under the conservation of two proposed surrogate species, the giant panda and the takin. We undertook a thorough study on the habitat requirements of these two endangered species, based on the analysis of their habitat preferences. The results revealed that the giant panda exhibits more specialized habitat preferences than does the takin and that habitat separation between these species mainly reflected differences in their dietary requirements and preferences. We suggest that these differences might facilitate their coexistence in sympatric areas. Meanwhile, results of a discriminant function analysis showed that protection of giant pandas would protect 82.1 % of the panda's habitat, but only 25.4 % of the takin's habitat and just 57.0 % of the joint habitats of these species. Importantly, our results also showed that a joint surrogate species approach to conservation would protect 86.9 % of the panda's habitat, 53.7 % of the takin's habitat, and 72.2 % of the joint habitats of these species. This is a higher degree of habitat protection than the single surrogate conservation of pandas. We conclude that the joint surrogate species approach should be adopted to improve biodiversity conservation.

Disequilibrium vegetation dynamics under future climate change

PREMISE OF THE STUDY

Near-future climate changes are likely to elicit major vegetation changes. Disequilibrium dynamics, which occur when vegetation comes out of equilibrium with climate, are potentially a key facet of these. Understanding these dynamics is crucial for making accurate predictions, informing conservation planning, and understanding likely changes in ecosystem function on time scales relevant to society. However, many predictive studies have instead focused on equilibrium end-points with little consideration of the transient trajectories.

METHODS

We review what we should expect in terms of disequilibrium vegetation dynamics over the next 50-200 yr, covering a broad range of research fields including paleoecology, macroecology, landscape ecology, vegetation science, plant ecology, invasion biology, global change biology, and ecosystem ecology.

KEY RESULTS

The expected climate changes are likely to induce marked vegetation disequilibrium with climate at both leading and trailing edges, with leading-edge disequilibrium dynamics due to lags in migration at continental to landscape scales, in local population build-up and succession, in local evolutionary responses, and in ecosystem development, and trailing-edge disequilibrium dynamics involving delayed local extinctions and slow losses of ecosystem structural components. Interactions with habitat loss and invasive pests and pathogens are likely to further contribute to disequilibrium dynamics. Predictive modeling and climate-change experiments are increasingly representing disequilibrium dynamics, but with scope for improvement.

CONCLUSIONS

The likely pervasiveness and complexity of vegetation disequilibrium is a major challenge for forecasting ecological dynamics and, combined with the high ecological importance of vegetation, also constitutes a major challenge for future nature conservation.