Seed longevity influences the success of ex situ storage and preservation of plant genetic diversity and is thus a critical factor in conservation efforts. Rapid seed ageing experiments at high temperature and high humidity have been widely used to classify seed longevity for hundreds of plant species, with potential implications for longevity in ex situ conservation. In this approach, radicle emergence (R) is normally used as a measure of the viability of the seeds. However, R could overestimate the level of normal seedling development and, consequently, the perceived longevity of seeds. Here, seed lifespan for 33 alpine species was compared to assess whether germination criteria could affect seed longevity parameters. Seeds were exposed to controlled ageing [45°C, 60% relative humidity (RH)] and regularly sampled for germination assessment as both radicle emergence (R) and radicle plus cotyledon emergence (R + C). The time taken in storage for viability to fall to 50% (p50) was determined using probit analysis, including either R or R + C data. A coefficient of overestimation of seed longevity (OESL, %) was determined. The results highlight significant differences in seed longevity estimates both across species and the germination criteria. For 17 species, seed longevity estimated by R was significantly higher than that estimated using R + C, resulting in large variation in OESL (0.54–9.01 d). The introduction of OESL facilitates effective screening for seed longevity and recovery, enhancing the overall efficiency of conservation strategies for diverse species.

The floristic composition of the understory plays a fundamental role in the long-term conservation of the diversity, structure, and function of mountain cloud forests in the Andes. We evaluated the relationship between the understory tree floristic composition of four types of predefined cloud forests and the canopy structure, the light transmitted to the understory, and the effect of topography. Through multivariate analysis, we found an environmental gradient correlated with light penetration into the understory and a gradient associated with the slope and, to a lesser extent, with the elevation. Then, we identified floristically well-differentiated ecological groups in response to environmental conditions; however, the groups only partially coincided with the understory composition of the predefined forests. We found environmental response species groups such as Roupala obovata and Beilschmiedia sulcata that are indicator species of sites with lower light penetration into the understory but with steeper slopes and higher elevation. In comparison, Clusia multiflora and Zanthoxylum quinduense to be the main indicator species from sites with greater light penetration into the understory and lower slope and elevation. These findings support appropriate species selection when implementing restoration strategies in forest landscape restoration plans.

In April 2019, the U.S. Fish and Wildlife Service (USFWS) released its recovery plan for the jaguar Panthera onca after several decades of discussion, litigation and controversy about the status of the species in the USA. The USFWS estimated that potential habitat, south of the Interstate-10 highway in Arizona and New Mexico, had a carrying capacity of c. six jaguars, and so focused its recovery programme on areas south of the USA–Mexico border. Here we present a systematic review of the modelling and assessment efforts over the last 25 years, with a focus on areas north of Interstate-10 in Arizona and New Mexico, outside the recovery unit considered by the USFWS. Despite differences in data inputs, methods, and analytical extent, the nine previous studies found support for potential suitable jaguar habitat in the central mountain ranges of Arizona and New Mexico. Applying slightly modified versions of the USFWS model and recalculating an Arizona-focused model over both states provided additional confirmation. Extending the area of consideration also substantially raised the carrying capacity of habitats in Arizona and New Mexico, from six to 90 or 151 adult jaguars, using the modified USFWS models. This review demonstrates the crucial ways in which choosing the extent of analysis influences the conclusions of a conservation plan. More importantly, it opens a new opportunity for jaguar conservation in North America that could help address threats from habitat losses, climate change and border infrastructure.

Since the ‘Grain to Green Program' was launched in 1999 in the Loess Plateau, China, the processes and patterns of ecological change have become important. Through the use of the fractional vegetation cover (FVC) index, this study examines the spatial distribution and temporal change of vegetation cover in the Loess Plateau during 2000–2014. Over this period more than 60% of the Loess Plateau has remained with little vegetation cover (FVC <30%). The spatial distribution pattern shows an overall increase from the NW to SE. Temporally, the vegetation cover exhibits a general trend of improvement. In 2000–2005, 2000–2010 and 2000–2014, the percentages of restored vegetation (vegetation with significantly increased FVC, P<0.05) were 2, 21 and 52%, respectively. The rate of vegetation cover restoration was highly variable among different bioclimatic zones. The expansion of restored vegetation was greater in the N of the Loess Plateau than in the south. Both human restoration activities and climatic fluctuation influenced the vegetation cover change. The ‘Grain to Green Program' emphasised vegetation restoration. Regional precipitation also had clear effects on vegetation cover. The results of this study reveal that vegetation change shows a non-linear process in response to climate and ecological restoration measures, and that the change gradually emerges over time. This study highlights the importance of considering the spatiotemporal variability in vegetation cover during the implementation of restoration programs, which could aid decision-making for the effective and sustainable management of large-scale restoration programs.

Extinctions have altered island ecosystems throughout the late Quaternary. Here, we review the main historic drivers of extinctions on islands, patterns in extinction chronologies between islands, and the potential for restoring ecosystems through reintroducing extirpated species. While some extinctions have been caused by climatic and environmental change, most have been caused by anthropogenic impacts. We propose a general model to describe patterns in these anthropogenic island extinctions. Hunting, habitat loss and the introduction of invasive predators accompanied prehistoric settlement and caused declines of endemic island species. Later settlement by European colonists brought further land development, a different suite of predators and new drivers, leading to more extinctions. Extinctions alter ecological networks, causing ripple effects for islands through the loss of ecosystem processes, functions and interactions between species. Reintroduction of extirpated species can help restore ecosystem function and processes, and can be guided by palaeoecology. However, reintroduction projects must also consider the cultural, social and economic needs of humans now inhabiting the islands and ensure resilience against future environmental and climate change.

Ecological restoration of shrub–steppe communities in the western United States is often hampered by invasion of exotic annual grasses during the process. An important question is how to create restored communities that can better resist reinvasion by these weeds. One hypothesis is that communities comprised of species that are functionally similar to the invader will best resist invasion, while an alternative hypothesis is that structurally more complex and diverse communities will result in more effective competitive exclusion. In this field experiment, we examined the effects of restored community structure on the invasion success of three annual grass weeds (downy brome, jointed goatgrass, and cereal rye). We created replicated community plots that varied in species composition, structural complexity and density, then seeded in annual grass weeds and measured their biomass and seed production the following year, and their cover after 1 and 3 yr. Annual grass weeds were not strongly suppressed by any of the restored communities, indicating that it was difficult for native species to completely capture available resources and exclude annual grass weeds in the first years after planting. Perennial grass monocultures, particularly of the early seral grass bottlebrush squirreltail, were the most highly invaded communities, while structurally complex and diverse mixtures of shrubs (big sagebrush, rubber rabbitbrush), perennial grasses (bluebunch wheatgrass and bottlebrush squirreltail) and forbs (Lewis flax, Utah sweetvetch, hairy golden aster, gooseberryleaf globemallow) were more resistant to invasion. These results suggest that restoration of sagebrush steppe communities resistant to annual grass invasion benefits from higher species diversity; significant reduction of weed propagule pressure prior to restoration may be required.

The distribution of the Critically Endangered tree Manglietia longipedunculata, of which there are only 11 known wild individuals, is restricted to the Nankunshan Nature Reserve in South China. The species is threatened with extinction because of its small number of individuals and the impediments to its reproduction (a combination of protogyny, a short period of stigma receptivity, and a lack of efficient pollinators). To reduce the risk of extinction we conducted two conservation translocation trials: one to augment the sole extant population, and the other 202 km north of the current range. The latter trial was a conservation introduction in which the goals were to increase the population and to buffer against the effects of climate change. We used emerged and grafted seedlings as translocation materials. We compared the survival, growth, and eco-physiological properties of emerged and grafted seedlings at the two sites. The survival rate and growth were higher for grafted seedlings than for emerged seedlings at both sites. Eco-physiological data indicated that grafted seedlings at both sites were as efficient or more so in light and water usage than wild individuals, whereas emerged seedlings were less efficient. Grafted seedlings attained the flowering stage sooner than emerged seedlings. Our study suggests that grafting can facilitate the augmentation and establishment of new populations of M. longipedunculata and perhaps of new populations of other threatened species facing reproductive difficulties and climate change.

Accurate measurements of seed rain are important for understanding tree reproduction (Greene & Johnson 1994), forest regeneration (Cole et al. 2010, Cubiña & Aide 2001, Howe et al. 2010, Zahawi & Augspurger 2006), forest ecology (Muller-Landau et al. 2008, Terborgh et al. 2011) and maintenance of community diversity (Harms et al. 2000). Seed traps generally consist of a bucket or net of a fixed area suspended 0.3–1 m above the ground, and seeds are typically collected once or twice per month. An implicit assumption of all seed-rain studies is that traps do not influence seed dispersal. Should birds perch on and defecate seeds into seed traps, seed abundance will be overestimated. This behaviour could produce a directional bias if birds perch on seed traps in one habitat more than others. To our knowledge, no study has considered this potential bias.