We tested for plague (Yersinia pestis) in a puma population in the Greater Yellowstone Ecosystem (GYE) over 9 years, overlapping a case when a boy in the area became infected with plague. Antibodies to Y. pestis were detected in 8 of 17 (47%) pumas tested by complement-enzyme-linked immunosorbent assay, and the organism itself was detected in 4 of 11 (36%) pumas tested after necropsy. Neither puma sex nor age was significantly associated with Y. pestis exposure or mortality, although our sample size was small. The overall prevalence of exposure we recorded was similar to that found along the western slope of Colorado, which is adjacent to the Four Corners region, a known plague hotspot in the USA. This suggests that: (1) Y. pestis may be present at higher levels in the GYE than previously assumed; (2) plague is a significant source of mortality for local pumas (6.6% of sub-adult and adult mortality); and (3) pumas may be a useful sentinel for potential risk of plague exposure to humans throughout the West. We would also emphasize that hunters and others handling pumas in this region should be made aware of the possibility of exposure.

Four grassland types at Cherrapunji, in northeastern India, namely the Osbeckia, Arundinella, Ischaemum, and Eragrostiella, types, were studied for soil nutrient losses through their hydrology and related soil-fertility changes. Losses through water and the consequent soil-fertility depletion were shown to be related to the frequency of the burn to which these grasslands are subjected. The Ischaemum type, with regular burning at 2-years' intervals, was the most adversely affected, compared with the Osbeckia type, which had not been burnt for the past 6 years.

In all the grassland types which were studied, the losses through water were high during the early part of the monsoon period, owing to the poor vegetation cover at that time. A desertified site with the Eragrostiella type of grassland had the lowest soil-fertility level, and had losses through removal in water that far exceeded the prevailing soil-nutrient level.

Fire can help in stabilizing the seral grassland vegetation if the soil is sufficiently deep and the frequency of the burn is not too great. On the other hand, too frequent perturbations by fire are apt to result in a desertified landscape that is difficult to restore.

Vandergeest (1996) suggested that the protected area (PA) system in Thailand is too large. He proposed that the state should recognize claims to private property rights within the PA system and subject remaining lands to collective property rights where villagers would be allowed to burn, cut and graze for commercial purposes. We disagree and summarize some of our concerns below.

The prevention of tropical forest deforestation is essential for mitigating climate change. We tested the machine learning algorithm Maxent to predict deforestation across the Peruvian Amazon. We used official annual 2001–2019 deforestation data to develop a predictive model and to test the model’s accuracy using near-real-time forest loss data for 2020. Distance from agricultural land and distance from roads were the predictor variables that contributed most to the final model, indicating that a narrower set of variables contribute nearly 80% of the information necessary for prediction at scale. The permutation importance indicating variable information not present in the other variables was also highest for distance from agricultural land and distance from roads, at 40.5% and 14.3%, respectively. The predictive model registered 73.2% of the 2020 early alerts in a high or very high risk category; less than 1% of forest cover in national protected areas were registered as very high risk, but buffer zones were far more vulnerable, with 15% of forest cover being in this category. To our knowledge, this is the first study to use 19 years of annual data for deforestation risk. The open-source machine learning method could be applied to other forest regions, at scale, to improve strategies for reducing future deforestation.

Increasing net-zero commitments by individuals, companies and governments have been accompanied by the growth of the voluntary offset market, including Reducing Emissions from Deforestation and Forest Degradation (REDD+). Technologies, notably blockchain, are starting to enter the REDD+ space and may have the potential to address issues such as additionality, permanence, leakage and property and community rights. In this Perspective, we first examine voluntary markets and the role forest carbon offsets have played within them, highlighting the evolution of REDD+ and the issues that have hindered its development. We then examine the potential of blockchain to address each of the issues, using the literature and emerging experience from the use of blockchain in the forestry space. We find that the technology may have the potential to improve verifiability, reduce transaction costs and, to a lesser degree, aid in addressing additionality and permanence concerns. However, greater learning from the emerging use of blockchain in pilot projects is needed to fully assess and maximize its potential.

We appreciate the effort and thought that Stewart-Oaten (2008) has put into his comment on our paper in Environmental Conservation (Bulleri et al. 2007). Clearly, the philosophical and methodological approaches used in ecological impact assessments (EIAs) warrant much further attention and discussion by ecologists. We would like, however, to clarify that the goals of our comment were far from summarizing available procedures and, even more, from expressing an opinion about which among these should be retained or rejected. This is quite well reflected by the contents of our paper (Bulleri et al. 2007). Our ‘main purpose’ (to quote Stewart-Oaten 2008) was to point out that the degree of naturalness of a site is irrelevant to whether or not some proposed disturbance causes an impact and that all disturbances potentially cause negative impacts.

Experimental trampling was carried out in recently-burned and unburned areas of a dry sclerophyll forest. Percentage cover was greatly reduced by burning and trampling. Plant numbers were relatively unaffected by burning, and trampling had approximately the same effect on plant numbers in recently-burned and unburned areas.

The reduction of cover and plant numbers to 50% of their original value by fewer than 16 passages was near to that predicted on the basis of the low primary productivity of the ground-flora, and suggests that this type of vegetation is quite vulnerable to trampling.

Incentives used to encourage local residents to support conservation range from integrated conservation and development projects (ICDPs), which indirectly connect improved livelihoods with biodiversity protection, to direct payments for ecosystem services (PES). A unique hybrid between these two strategies, the Arabuko-Sokoke Schools and Ecotourism Scheme (ASSETS), provides secondary-school bursaries to encourage stewardship of a biodiverse highly-imperiled Kenyan forest. Household surveys and semi-structured interviews were used to assess the effectiveness of ASSETS by comparing attitudes and perceptions toward the forest among scheme beneficiaries and non-beneficiaries. The most commonly identified benefit of the forest was resource extraction (for example fuelwood), followed by ecosystem services (such as source of rain). Those in favour of forest clearing tended not to be ASSETS beneficiaries, were less-educated, and were less likely to mention ecosystem services and tourism as forest benefits. ASSETS appears to shape pro-conservation attitudes among beneficiaries and foster a sense of responsibility toward the forest. Challenges for ASSETS are similar to those faced by many conservation and development projects, namely unsteady funding and the risk that the extremely poor may be overlooked. ASSETS may serve as an effective hybrid between the PES and ICDP approaches, and such educational support provides a promising conservation incentive.

Higgins (2005) has shown that increased human physical activity in the USA could lead to both improvements in physical health and reductions in oil consumption by motor vehicles, thereby also reducing carbon emissions. It is an intriguing idea and, as the health costs of obesity are so high, the potential health and environmental savings could be vast. These questions deserve wider attention, as all the trends suggest that consumption of both fossil fuels and food calories (combined with more sedentary lifestyles) will continue to rise in the coming years.

Tropical wetlands are of great ecological importance and are worthy of widespread and vigorous conservation efforts. They are, however, very susceptible to environmental changes which often result from human activities. Waigani swamp near Port Moresby, Papua New Guinea, comprises a number of small, shallow lakes, the largest of which, Waigani Lake, has a surface area of 120 ha. This Lake now has nutrient-rich water with very high phytoplankton populations owing to sewage effluent disposal.

Changes in the macrophyte flora and vegetation of Waigani Lake are documented in aerial photographs taken between 1942 and 1981. From 1942 to 1956 the Lake was dominated by emergent vegetation, and there was very little open water. Between 1956 and 1966 this emergent vegetation was replaced by dense stands of nymphaeids. In 1965, sewage disposal into Waigani Lake began and by 1974 only a few small stands of nymphaeids remained. By 1978 no nymphaeids could be found in Waigani Lake. The decline in the nymphaeid cover of Waigani Lake was accompanied by a regression of the surrounding reed-swamp. Two other lakes near Port Moresby are nutrient-poor and have a dominant and diverse macrophyte flora, being probably more comparable with Waigani Lake prior to its enrichment—apart from a recent takeover by a pestiferous free-floating water-fern.

Wildland fire management directly affects the forces of natural selection to which plant taxa become adapted. Changes in a fire regime will often result in changes in the relative abundance of particular species, and may cause the extinction of some of them. Life-history characteristics are important indicators of adaptation to recurrent disturbance, such as may be produced by fire. The incorporation of these characteristics in a computer simulation allows of the projection of species abundance under different fire regimes.

Through prescribed burning and fire suppression, fire interval and fire intensity can be controlled to some extent. The fire intensity for given sets of fuel, site, and meteoro-logical conditions, representing given fire-intervals, is calculated with the use of a fire behaviour computer simulation. These results are incorporated in computer simulation of the demographic competition of the five dominant shrub species of coastal sage-scrub in the Santa Monica Mountains of southern California: Artemisia californica, Encelia californica, Eriogonum cinereum, Salvia leucophylla, and S. mellifera. The model incorporates resprouting proportions, seedling establishment, and growth, and assumes survivorship rates in simulating scramble competition for space. Foliar cover-values of the five species are projected for nine different fire regimes. Short fire-intervals of the order of 10–20 years, such as might occur under a regime of prescribed burning, may eliminate or greatly reduce some species, whereas longer intervals allow the maintenance of a more diverse community especially of shrubs. Fixed and variable interval-lengths do not produce appreciably different results.

This study suggests that prescribed burning at 10–20 years' intervals should not be used indiscriminately to reduce wildland fire hazard in southern California. The fire intervals that will reduce the hazard, may eliminate some dominant native shrub species. A ‘natural’ fire regime which would maintain the natural vegetation while constituting only a minimum hazard to homesites may, unfortunately, be mutually exclusive goals in the coastal sage-scrub of southern California.

A number of recent publications have pointed out the accelerating speed at which ecosystems and biodiversity are being lost (United Nations Development Programme/United Nations Environment Programme/The World Bank/The World Resources Institute 2000). The general view is that conservation can only be achieved in a global network of protected areas (see Pimm et al. 2001). To safeguard the most important ecosystems, Myers et al. (2000) have suggested that we primarily conserve 25 biodiversity hotspots, in particular forests, comprising 1.4% of the land surface of the Earth. The costs for the conservation of these hotspots have been estimated at US$ 500 million per year (Myers et al. 2000), while the costs of a global network of protected areas may even reach US$ 27.5 billion per year (James et al. 1999). Even though these costs may seem minor compared to, for example, the costs of global armament, governments in developing countries and environmental organizations are clearly not in the position to finance conservation. It is thus urgent to raise additional funds to safeguard biodiversity. In the following, I suggest a twofold strategy, based on tourism.

The Kirby Canyon Conservation Agreement was designed to provide protection of the Bay Checkerspot Butterfly (Euphydryas editha bayensis) while allowing development of an extensive solid-waste landfill in the habitat of that threatened subspecies. Elements of the programme include 1) biological research; 2) habitat acquisition; 3) habitat management; 4) restoration and revegetation activities; and 5) off-site recovery, including reintroduc-tion of the Butterfly into an unoccupied suitable habitat.

The high likelihood of success of this agreement reflects the availability of detailed life-history information, the known ecological characteristics of the Butterfly, and the geographic scale of the proposed development. This agreement should provide a useful model for the resolution of potential conflicts between endangered invertebrates and resource development in urban corridors elsewhere.

There is burgeoning interest in predicting road development because of the wide ranging important socioeconomic and environmental issues that roads present, including the close links between road development, deforestation and biodiversity loss. This is especially the case in developing nations, which are high in natural resources, where road development is rapid and often not centrally managed. Characterization of large scale spatio-temporal patterns in road network development has been greatly overlooked to date. This paper examines the spatio-temporal dynamics of road density across the Brazilian Amazon and assesses the relative contributions of local versus neighbourhood effects for temporal changes in road density at regional scales. To achieve this, a combination of statistical analyses and model-data fusion techniques inspired by studies of spatio-temporal dynamics of populations in ecology and epidemiology were used. The emergent development may be approximated by local growth that is logistic through time and directional dispersal. The current rates and dominant direction of development may be inferred, by assuming that roads develop at a rate of 55 km per year. Large areas of the Amazon will be subject to extensive anthropogenic change should the observed patterns of road development continue.