Pre-emptive conservation versus “fire-fighting”: A decision theoretic approach

How can conservation planners optimally and effectively allocate limited resources between imminently threatened and presently secure areas? Such choices must be made at multiple spatial scales involving a variety of conservation targets. Allocation strategies range from a “fire-fighting” approach, which gives priority to heavily developed areas at high risk of further habitat loss, to a “pre-emptive” approach giving priority to intact habitat tracts before they become threatened. We determined optimal dynamic reserve selection strategies when selections are made in imminently threatened and presently secure areas that will become threatened at uncertain times in the future. The objective was to maximize the expected number of endemic species conserved, predicted with species-area curves. The model was solved for three forms of species-area curve proposed in theoretical studies of habitat loss. Alternative scenarios were considered on the relationship between land prices and development risk. For the most commonly proposed form of the species-area relationship, the fire-fighting approach is optimal even if land prices rise substantially when presently secure areas become threatened. This reflects the assumption that species decline accelerates only after a large proportion of original habitat has been lost. The possibility of large species losses at lower levels of habitat loss justifies at least some pre-emptive conservation, even if land prices are not correlated with threat. If species decline is proportional with habitat loss, the optimal conservation strategy depends strongly on land price dynamics.     

Contrasting measures of fitness to classify habitat quality for the black-throated sparrow (Amphispiza bilineata)

Habitat quality is an important consideration when identifying source and sink habitat and setting priority areas for avian conservation. The problem is that different measures may lead to different conclusions about habitat quality, and may also vary in the resources required to estimate them. Individual level measures, such as nest success, and fecundity, will often identify different high quality habitats than population level measures, such as abundance or the number of fledglings produced per unit area. We tested measures of fitness in the Black-throated Sparrow both at the individual and at the population level for six habitats in the northern Chihuahuan Desert, to explore their value as indicators of habitat quality. We compared clutch size, number of nestlings per nest, number of fledglings per successful nest, nest density, nest success, daily nest survival rate, season-long fecundity, number of fledglings produced per 100 ha, and adult abundance, in each habitat type. We also modeled source-sink dynamics to estimate the scale at which they operate, to infer survival rates, and to ascertain the relative source potential of each habitat. We found that fecundity is the best indicator of individual level habitat quality but a poor indicator of population level habitat quality. Nest success (or fecundity, if resources are available to adequately estimate it) plus nest density provide the most robust indicator of population level habitat quality, which is the level at which priority habitats for conservation should be identified. Mesa grassland and black grama grassland functioned as source habitats most consistently, and mesquite was consistently a sink but also probably a reservoir of individuals available to occupy other habitats.     

Assessing critical habitat: Evaluating the relative contribution of habitats to population persistence

A principal challenge of species conservation is to identify the specific habitats that are essential for long-term persistence or recovery of imperiled species. However, many commonly used approaches to identify important habitats do not provide direct insight into the contribution of those habitats to population persistence. To assess how habitats contribute to overall population viability and characterize their relative importance, a spatially-explicit population viability model was used to integrate a species occurrence model with habitat quality and demographic information to simulate the population dynamics of the Ord’s kangaroo rat (Dipodomys ordii) in Alberta, Canada. Long-term productivity (births-deaths) in each patch was simulated and iterative patch removal experiments were conducted to generate estimates of the relative contribution of habitat types to overall population viability. Our results indicated that natural dune habitats are crucial for population viability, while disturbed/human-created habitats make a minor contribution to population persistence. The results also suggest that the habitats currently available to Ord’s kangaroo rats in Alberta are unlikely to support long-term persistence. Our approach was useful for identifying habitats that did not contribute to population viability. A large proportion of habitat (39%) represented sinks and their removal increased estimated population viability. The integration of population dynamics with habitat quality and occurrence data can be invaluable when assessing critical habitat, particularly in regions with variable habitat quality. Approaches that do not incorporate population dynamics may undermine conservation efforts by under- or over-estimating the value of habitats, erroneously protecting sink habitats, or failing to prioritize key source habitats.     

Underground mining can contribute to freshwater biodiversity conservation: Allogenic succession forms suitable habitats for dragonflies

Human-induced changes negatively affect all components of freshwater ecosystems and comprise the major cause of global loss of diversity and the biotic homogenization of freshwater faunas. The high diversity of dragonflies in heavily industrialized areas is therefore paradoxical, to say the least. We compared diversity of dragonflies in three main freshwater habitat types (natural and human-made) occurring in Upper Silesia (Central Europe). We used multivariate methods and diversity indices for a general analysis, comprising both species richness and the species composition of assemblages. We recorded 50 species in mine subsidence pools from the total of 54 sampled species. These included a high proportion of habitat specialists (typically threatened species). We emphasize that secondary habitats (e.g. spontaneously originated mine subsidence pools) should not a priori be regarded as ecological traps, because these often are the available habitats with highest quality. These habitats significantly outweigh ponds in species richness and proportion of habitat specialists. The conservation potential of specific secondary habitats lies in the fact that these habitats can substitute for very rare natural wetlands often restricted to higher elevations. We assume that high diversity in this type of secondary habitats is not random, but rather that it depends on environmental heterogeneity caused by a specific allogenic succession process occurring as a direct consequence of mining.     

Future habitat loss and the conservation of plant biodiversity

Rapid land-use and climate changes are projected to cause broad-scale global land-cover transformation that will increase species extinction rates. We assessed the exposure of globally threatened plant biodiversity to future habitat loss over the first half of this century by testing country-level associations between threatened plant species richness and future habitat loss owing to land-use and climate changes, separately. In countries overlapping Biodiversity Hotspots, plant species endangerment increases with climate change-driven habitat loss. This association suggests that many currently threatened plant species will become extinct owing to anthropogenic climate change in the absence of potentially mitigating factors such as natural and assisted range shift, and physiological and genetic adaptations. Countries rich in threatened species, which are also projected to have relatively high total future habitat loss, are concentrated around the equator. Because poverty and poor governance can compromise conservation, we considered the economic condition and quality of governance with the degree of plant species endangerment and future habitat loss to prioritize countries based on conservation need. We identified Angola, Cuba, Democratic Republic of Congo, Ethiopia, Kenya, Laos, Madagascar, Myanmar, Nepal, Tajikistan, and Tanzania as the countries in greatest need of conservation assistance. For conservation endeavors to be effective, the conservation capacity of these high-need countries needs to be improved by assisting political stability and economic sustainability. We make policy recommendations that aim to mitigate climate change, promote plant species conservation, and improve the economic conditions and quality of governance in countries with high conservation need.     

碳达峰与碳中和目标下水土保持碳汇的机理、途径及特征

[目的] 瞄准中国碳达峰、碳中和目标及其时间表,探索水土保持碳汇的主要途径与特征,为全面提升水土保持碳汇能力,科学推进水土流失综合治理高质量发展提供借鉴。[方法] 参考和借鉴国内外相关研究成果,系统性地分析了水土保持碳汇的学科应用基础及其协同作用机理,主要途径和物质表现,总结提出了水土保持碳汇的主要特征。[结果] 水土保持碳汇作用是在植物措施、工程措施和耕作措施3大类水土保持措施的共同参与下,通过植物、土壤和水体等多种途径协同发挥的,可消减大气中CO₂并将其转化为多种含碳化合物储存在植物及其产品、土壤和水体中。水土保持碳汇途径包括植物途径、土壤途径和水体途径。水土保持碳汇物质包括生物量、无生命有机质、土壤有机质和水体碳素。水土保持碳汇主要特征包括多种治理措施共同作用;多种碳汇途径相互交织;碳汇物质的现地性;碳汇特征短历时碳汇明显,全周期呈弱碳汇。[结论] 生态文明建设新阶段的水土保持工作,应全面推行碳汇水土保持,实施碳汇监测评价,扩大高碳汇水土保持措施,开展清洁生态小流域建设,避免水土流失与其治理措施损毁导致的碳排放,进一步提升碳汇增量,巩固碳汇能力。     

Plant species extinction debt in a temperate biodiversity hotspot: Community, species and functional traits approaches

Destruction and fragmentation of (semi-) natural habitats are considered the main causes of biodiversity loss worldwide. Plant species may exhibit a slow response to fragmentation, resulting in the development of an extinction debt in fragmented plant communities. The detection of extinction debt is of primary importance in habitat conservation strategies. We applied two different approaches proposed in the literature to identify extinction debt in South-East Belgium calcareous grasslands. The first method compared species richness between stable and fragmented habitat patches. The second explored correlations between current species richness and current and past landscape configurations using multiple regression analyses. We subsequently examined results generated by both methods. In addition, we proposed techniques to identify species that are more likely to support extinction debt and associated functional traits. We estimated a respective extinction debt of approximately 28% and 35% of the total and specialist species richness. Similar results were obtained from both methods. We identified 15 threatened specialist species under the current landscape configuration. It is likely the landscape configuration no longer supports the species habitat requirements. We demonstrated that non-clonal species are most threatened, as well as taxa that cannot persist in degraded habitats and form only sparsely distributed populations. We discussed our results in light of other studies in similar habitats, and the overall implications for habitat conservation.     

A large-scale conservation perspective considering endemic fishes of the North American plains

Regions with unique habitats often harbor endemic taxa associated with temporally stable habitats. We identified such habitats that sustain endemic fishes in the plains of North America. We also summarized threats to their conservation and identified remnant habitats that still harbor endemic fishes (refuges) based on post-1989 surveys. Major springs, smaller, spring-fed streams, larger rivers, and euryhaline habitats were associated with a total of 49 endemics. Endemism was attributable to climatic refugia associated with each habitat type and dispersal limitation among major river drainages and springs. Forty-one endemic fishes (84%) were declining or extinct. Dewatering, habitat fragmentation, and habitat degradation were main causes of declines, often present together. Pollution and non-native species were also threats in many cases. Evidence for 53 existing refuges was found. We considered 34 refuges to be “high-quality” because they harbored three or more endemics. Twenty of these (those with available data) maintained consistent streamflow regimes for at least 50 years up to 2009. Case studies suggest high stream length, more natural flow regimes, and fewer direct human impacts are features of high-quality refuges, but extinction thresholds are unquantified and extinction debts of refuges are unknown. Limited information on past extinctions suggests drought, a natural feature of the plains, combines with other threats to eliminate remnant endemic populations. Long-term conservation planning requires identification, protection, and restoration of high-quality refuges to reduce extinction risk, especially during future drought periods. Planning should be integrated with regional water resource planning, given scarcity of water in the region.     

Peat swamp forest avifauna of Central Kalimantan, Indonesia: Effects of habitat loss and degradation

Peat swamp forest is a unique wetland ecosystem covering extensive areas in Southeast Asia that has received relatively little scientific attention and is now being lost at a rapid pace. This study examines the effects of anthropogenic degradation on bird communities in disturbed peat swamp forest habitats – namely, intact logged forest, a degraded forest fragment, and non-forest regrowth – in Central Kalimantan, Indonesia. Results show that species richness was significantly higher and species composition significantly different in intact logged forest in comparison to the degraded forest fragment and non-forested area. Nectarivore and tree foliage-gleaning insectivore abundance declined outside the intact forest, while the regrowth was dominated by the yellow vented bulbul, an open country insectivore–frugivore. Surveys reveal that large intact tracts of logged peat swamp forest can harbour threatened and near threatened bird species (36% of records) and thus play a role in their conservation, especially for a few habitat specialists. Given the extent of unmanaged degraded peatlands and continuing pressure to development them, urgent conservation actions are needed to rehabilitate and protect this ecosystem.     

Determining the spatial scale for conservation purposes - an example with grizzly bears

This study suggests procedures for determining the spatial scale for conservation guidelines for animals, giving an illustration with an analysis of grizzly bear habitat selection. Bear densities were sampled by identifying hairs at bait stations in British Columbia. Habitat variables were measured using remote sensing. Spatial scale was changed by varying the window size over which the variables were averaged. First, the spatial pattern of bears was studied, measuring the patchiness in bear densities at a variety of spatial scales, by calculating the correlation in bear densities between adjacent windows. This was repeated for the habitat variables. Finally, the overall interaction between bears and habitats was analysed, measuring the strength of habitat selection at different spatial scales. There are three domains of scale: at 2-4 km, bears and habitats are patchy, at 5-10 km, bears select for habitats, and at 40+ km, habitats are patchy and bears select for habitats. At scales of 40+ km, bears selected for: (i) higher slopes, or (ii) higher slopes, and some combination of more avalanche chutes, fewer roads and trees, higher elevations, and less logged land. Within 15 km areas, bears selected for 6 km areas that are either at higher elevations, or at higher elevations and had fewer trees. The relationship of conservation guidelines at different spatial scales should be determined by measuring and comparing hierarchical to non-hierarchical selection. The scales that bears select for habitats roughly correspond to the scales used in present grizzly bear conservation plans in British Columbia.     

Estimating habitat suitability and potential population size for brown bears in the Eastern Alps

According to the Habitats Directive of the European Union, a favorable conservation status for the brown bear (Ursus arctos) should be targeted at the population level in large contiguous habitats such as the Alps, the largest mountain range in Europe. However, in most of the Alps brown bears are extinct and habitat suitability in these areas is often questionable. For this paper, radio-tracking data from four projects with 42 individual bears was compiled to assess habitat suitability. Discrete-choice models with random bear effects were fitted and compared to results obtained from compositional analysis and logistic regression. Sound definition of the available area in the discrete-choice model turned out to be essential. Brown bears showed a preference for forested and steep habitats and an avoidance of roads.Results from the three approaches were used to predict habitat suitability across the entire range of the Eastern Alps. Minimum potential population size was projected based on observed densities in Trentino and Central Austria, and ranged from 1228 to 1625 individuals, with 518–686 mature bears. This would satisfy a favorable conservation status. The developed methodology also has wide applicability to quantification of habitat suitability and potential population size in other cases where species are at risk.     

Estimating occupancy of a data deficient mammalian species living in tropical rainforests: Sun bears in the Kerinci Seblat region, Sumatra

Tropical mammals represent some of the most threatened species, but also the least known because they tend to be difficult to study. To objectively evaluate the conservation status of these species, standardized methods are urgently required. The sun bear Helarctos malayanus is a case in point: it is cryptic, difficult to detect and consequently classified on the IUCN Red List as Data Deficient, and the highest priority for bear conservation research. In this study, we apply a detection/non-detection sampling technique using camera trap data with environmental covariates to estimate sun bear occupancy from three tropical forest study areas with different levels of degradation and protection status in Sumatra. Sun bear detections, and encounter rates, were highest in one of the primary forest study areas, but sun bear occupancy was highest in the degraded forest study area. Whilst, sun bears were recorded at a greater proportion of camera placements in degraded forest, these records were often on only one occasion at each placement, which greatly increased the final occupancy estimate. Primary forests with their large fruiting trees undoubtedly represent good sun bear habitat, but our results indicate that degraded forest can also represent important habitat. These forests should therefore not be considered as having limited conservation value and assigned to other uses, such as oil palm production, as has previously happened in Sumatra. Estimating occupancy between years will yield information on the population trends of sun bears and other tropical mammals, which can be used to provide more reliable conservation assessments.     

Can natural disturbance-based forestry rescue a declining population of grizzly bears?

Forest managers are increasingly considering historic patterns of natural forest disturbance as a model for forest harvesting and as a coarse-filter ecosystem management tool. We evaluated the long-term (100-year) persistence of a grizzly bear population in Alberta, Canada using forest simulations and habitat modelling. Even with harvesting the same volume of timber, natural disturbance-based forestry resulted in a larger human footprint than traditional two-pass forestry with road densities reaching 1.39 km/km² or more than three times baseline conditions and suggested maximum levels of security for grizzly bears. Because bears favour young forests and edges where food resources are plentiful, a future shift to young forests and more edge habitat resulted in a 20% projected increase in habitat quality and a 10% projected increase in potential carrying capacity. Human-caused mortality risk, however, offset any projected gains in habitat and carrying capacity resulting in the loss of all secure, unprotected territories, regardless of forest harvest method, within the first 20-30 years of simulation. We suggest that natural disturbance-based forestry is an ill-suited management tool for sustaining declining populations of grizzly bears. A management model that explicitly considers road access is more likely to improve grizzly bear population persistence than changing the size of clear-cuts. In fact, large clear cuts might be counter productive for bears since a diversity of habitats within each bear’s home range is more likely to buffer against future uncertainties.     

Assessing conservation priorities for insects: status of water beetles in southeast Spain

We propose an objective method for assessing the vulnerability of species and for prioritizing species and populations for conservation, especially insects. Species of water beetles from two Spanish provinces of the southeast of the Iberian Peninsula were ranked according to their conservation priority at the local, national and global levels taking into consideration a set of six variables: general distribution, endemicity, rarity, persistence, habitat rarity and habitat loss. Each variable was categorized into four ranks (0-3) of increasing risk for survival. Ochthebius glaber, Ochthebius irenae, Ochthebius montesi, Ochthebius albacetinus and Hydraena mecai were seen to be the most vulnerable, for which reason we propose they should be included in the national red list. Furthermore, O. glaber, O. irenae and O. montesi are proposed for inclusion in the IUCN red list as “Vulnerable”. These species are Iberian endemisms, with geographic ranges restricted to the southeast, and are threatened by habitat loss. Effective protection of these species requires measures directed at the conservation of their habitats. Crucial target habitats for protection in the southeast of the Iberian Peninsula include freshwater streams at medium altitudes, saline streams and endorreic lagoons.     

An integrated analysis into the causes of ungulate mortality in the Wanda Mountains (Heilongjiang Province, China) and an evaluation of habitat quality

As part of our ungulate population protection program, the specific causes of ungulate mortality were examined and the effect of single habitat on habitat selection by ungulate analyzed. An integrated occurrence–mortality model for three ungulate species (wild boar Sus scrofa L., red deer Cervus elaphus L. and roe deer Capreolus capreolus Pallas) within the Wanda Mountains of Heilongjiang Province, China was then created. Results showed that steel cable snares and poison, used to kill ungulates, were the primary threats to survival of wild boar (40.07% poison, 27.79% cable snares), red deer (51.35% poison, 40.54% cable snares) and roe deer (29.31% poison, 56.90% cable snares). Furthermore, we found evidence that aspect, slope, elevation and forest type are important factors in determining ungulate habitat preference. The integrated occurrence–mortality model indicated that 46.39% of suitable habitat was associated with mortality risk. This model correctly classified 8.06% (297.49 km²) of the study area as unsuitable habitat, 5.43% (200.44 km²) as first attractive sink-like habitat, 32.76% (1209.85 km²) as second attractive sink-like habitat, 8.20% (302.77 km²) as third attractive sink-like habitat, and 8.91% (329.00 km²), 30.53% (1127.22 km²) and 6.11% (225.29 km²) as first, second and third source-like habitats, respectively. The results indicate that source-like habitats should be preserved to prevent habitat loss and degradation, while attractive sink-like habitats should be managed effectively to mitigate mortality risks. In particular, the various authorities need to be more proactive (increase patrolling, thereby providing employment, educational opportunities and increasing income) to reduce human-caused ungulate mortality.     

Landscape evaluation of female black bear habitat effectiveness and capability in the North Cascades, Washington

We used logistic regression to derive scaled resource selection functions (RSFs) for female black bears at two study areas in the North Cascades Mountains. We tested the hypothesis that the influence of roads would result in potential habitat effectiveness (RSFs without the influence of roads) being greater than realized habitat effectiveness (RSFs with roads). Roads consistently had a negative influence on black bear RSFs across seasons and study areas. Roads reduced habitat effectiveness during all seasons at both study areas and changes in the potential habitat values ranged from 1.7% to 16.9%. The greatest reduction in habitat values occurred during the early-season on the west-side study area due to high open road densities. These results support the hypothesis that roads reduce habitat effectiveness for black bears. The influence of roads could be reduced through road closures to reduce open road densities and limit traffic volumes. We then used the scaled RSFs in a habitat-based population model to assess the influences of timber harvest and roads on potential black bear population sizes. On the west-side study area the potential black bear population size was most influenced by moderate use roads and timber harvest during the early-season (41% reduction). On the east-side study area, low use roads had the greatest effect on potential black bear population during the early-season (10% reduction). During the late-season, in both study areas, roads had less influence on the potential population sizes as bears were able to access habitats away from roads. The habitat-population model provided reasonable estimates of bear densities compared to other study areas with similar habitats and could be extrapolated to estimate potential black bear populations in other areas with similar habitats. This approach may provide a useful link between the landscape ecology and population biology of black bears, and could eventually be useful in the development of habitat-based population viability analyses.     

Prioritisation of conservation areas in the Western Ghats, India

Areas of high conservation value were identified in the Western Ghats using a systematic conservation planning approach. Surrogates were chosen and assessed for effectiveness on the basis of spatial congruence using Pearson’s correlations and Mantel’s tests. The surrogates were, threatened and endemic plant and vertebrate species, unfragmented forest areas, dry forests, sub-regionally rare vegetation types, and a remotely sensed surrogate for unique evergreen ecosystems. At the scale of this analysis, amphibian richness was most highly correlated with overall threatened and endemic species richness, whereas mammals, especially wide-ranging species, were better at capturing overall animal and habitat diversity. There was a significant relationship between a remote sensing based habitat surrogate and endemic tree diversity and composition. None of the taxa or habitats served as a complete surrogate for the others. Sites were prioritised on the basis of their irreplaceability value using all five surrogates. Two alternative reserve networks are presented, one with minimal representation of surrogates, and the second with 3 occurrences of each species and 25% of each habitat type. These networks cover 8% and 29% of the region respectively. Seventy percent of the completely irreplaceable sites are outside the current protected area network. While the existing protected area network meets the minimal representation target for 88% of the species chosen in this study and all of the habitat surrogates, it is not representative with regard to amphibians, endemic tree species and small mammals. Much of the prioritised unprotected area is under reserve forests and can thus be incorporated into a wider network of conservation areas.     

Environmentally biased fragmentation of oak savanna habitat on southeastern Vancouver Island, Canada

Quantifying the degree to which natural or protected areas are representative of a specified baseline provides critical information to conservation prioritization schemes. We report results on southeastern Vancouver Island, Canada, where we compared environmental conditions represented across the entire landscape, in oak savanna habitats prior to European settlement (<1850), and in both protected and unprotected oak savannas in the present-day. In this region, oak savannas represent a rare habitat type, harboring many threatened species. Before European settlement, oak savannas occurred in a distinctly different subset of environmental conditions than they do today. Compared to the entire landscape, oak savannas were historically found predominantly in warm, dry, flat, and low-lying areas, but habitat destruction has left oak savannas in largely the exact opposite set of conditions at present. Thus, the range of conditions in both protected and unprotected oak savannas at present are highly unrepresentative of historical conditions. It appears that fire management by indigenous peoples maintained oak savannas historically across large areas of flat low-lying conditions with deep soils, where succession otherwise produces closed coniferous forest. These areas have since been almost entirely converted to agricultural and urban areas, leaving remnant oak savannas largely on steep, rocky hilltops, where the habitat is maintained by shallow soils. Our results provide quantitative guidance for setting conservation priorities for oak savannas in this region, while highlighting the important general issue of the major role traditional land-use practices can play in shaping landscapes, and therefore in influencing the baselines used to set conservation priorities.     

Beyond the wetland border: Estimating the impact of roads for two species of water snakes

We used models integrating road maps, traffic volume, and snake movements to examine the potential for roads to contribute to mortality in two species of water snakes that differ in their vagility, use of terrestrial habitats, and conservation status. Road networks and traffic volumes typical of three regions in Indiana, USA, may account for mortality of 14-21% of the population per year in the more vagile, terrestrial, and imperiled copperbelly water snake (Nerodia erythrogaster neglecta) but only 3-5% mortality in the more sedentary, aquatic, and common northern water snake (Nerodia sipedon). The majority (>91%) of road crossings and associated mortality are predicted to occur during overland migrations to other wetlands, suggesting roads bisecting travel routes between wetlands may function as mortality sinks. Our models highlight the proportionately greater risk of mortality for the more vagile and imperiled species, N. e. neglecta, and suggest current wetland conservation strategies that focus on the wetland alone are unlikely to adequately protect wetland biodiversity from certain types of anthropogenic habitat modification. What is needed is a landscape approach to wetland conservation that considers not only the quality of wetlands and nearby terrestrial habitats, but also ensures that terrestrial corridors between wetlands remain permeable and offer safe passage for wildlife.     

The cost of postponing biodiversity conservation in Mexico

Though Neotropical countries are the most species rich in the world, their biodiversity is threatened by the loss of native vegetation. Land conversion in Mexico during the last 30 years has been extensive and is representative of that of other developing countries. However, the effects of land use change on the required size and configuration of an adequate biological conservation area network are largely unknown. It is shown here that endemic mammals in Mexico could have been protected considerably more economically if a conservation plan had been implemented in 1970 than is possible today due to extensive conversion of primary habitats. Analysis of the distributions of 86 endemic mammal species in 1970, 1976, 1993, and 2000 indicates that the distributions of 90% of the species shrank during this 30-year period. At each time step, optimal conservation area networks were selected to represent all species. 90% more land must be protected after 2000 to protect adequate mammal habitat than would have been required in 1970. In addition, under a realistic conservation budget, 79% fewer species can be represented adequately in a conservation area network after 2000 compared to 1970. This provides an incentive for rapid conservation action in Mexico and other biodiversity hotspots with comparable deforestation rates, including Burma, Ecuador, Indonesia, the Philippines, and Sri Lanka. Due to ongoing habitat degradation, the efficiency of a conservation plan decreases with delays in its implementation.