Global priority areas for ecosystem restoration

In the paper

“A previous global assessment of areas where trees could be planted indicated there is considerable scope for carbon drawdown 6 , but afforestation of nonforest biomes is likely to have negative consequences for native biodiversity 7,8 .”

What the sources say

• ?Not checked — no full text of the sourcecites [6] Bastin, J. F. et al. The global tree restoration potential. Science 365, 76–79 (2019). source
• ?Not checked — no full text of the sourcecites [7] Chazdon, R. & Brancalion, P. Restoring forests as a means to many ends. Science 365, 24–25 (2019). source
• Supported

  The citation to this paper is attached to the biodiversity claim, not the preceding claim about global carbon-drawdown potential. In “The Need for Biodiversity and Habitat Safeguards” (p. 9), the paper says afforestation of grassy biomes leads to biodiversity loss; “Watch Out for the Trade-Offs” (p. 12) likewise warns that tree planting is not always beneficial for biodiversity in non-forest systems. (LLM, conf=0.93)

  cites [8] Temperton, V. M. et al. Step back from the forest and step up to the Bonn challenge: how a broad ecological perspective can promote successful landscape restoration. Restor. Ecol. 27, 705–719 (2019). source

In the paper

“This more-dispersed restoration could have benefits in terms of increased representation of ecological communities and local benefits of nature to people 33,34 .”

What the sources say

• ?Not checked — no full text of the sourcecites [33] Anderson, C. B. et al. Determining nature’s contributions to achieve the sustainable development goals. Sustain. Sci. 14, 543–547 (2019). source
• ?Could not verify

  The Introduction describes ecological communities and nature’s contributions to people, and section 4.3 discusses conservation and local ecosystem services. Neither passage addresses whether more-dispersed restoration increases ecological representation or local benefits; searches for restoration and its spatial distribution found no such comparison in our copy. (LLM, conf=0.72)

  cites [34] Martín-López, B. et al. Nature’s contributions to people in mountains: a review. PLoS ONE 14, e0217847 (2019). sourceExperimental — accuracy not yet measured

In the paper

“Introducing cost minimization as an extra objective of the optimization markedly improves the cost effectiveness of solutions (trade-off curve with point V in Fig. 3) consistent with previous studies 9,15 .”

What the sources say

• Supported

  The Results (p. 9) compare an efficiency frontier that excludes costs with a cost-effective frontier that includes them. A compromise solution on the latter achieves an eightfold increase in cost-effectiveness for biodiversity conservation relative to the baseline, supporting the cited point in this restoration-planning setting. (LLM, conf=0.91)

  cites [9] Strassburg, B. B. N. et al. Strategic approaches to restoring ecosystems can triple conservation gains and halve costs. Nat. Ecol. Evol. 3, 62–70 (2019). source
• ?Not checked — no full text of the sourcecites [15] Ando, A., Camm, J., Polasky, S. & Solow, A. Species distributions, land values, and efficient conservation. Science 279, 2126–2128 (1998). source

In the paper

“identify overlaps between priority areas for different objectives 10 -but also indicate considerable trade-offs among these objectives 9 .”

What the sources say

• Supported

  The citation follows the clause about trade-offs. In the Results, the paper reports that areas with greater climate-mitigation benefits tended to have lower adaptation benefits, and that areas with greater benefits across several objectives generally had lower restoration feasibility. The Discussion likewise describes spatial mismatches and potential trade-offs. (LLM, conf=0.90)

  cites [10] Brancalion, P. H. S. et al. Global restoration opportunities in tropical rainforest landscapes. Sci. Adv. 5, eaav3223 (2019). source
• Supported

  Citation 9 is attached to the trade-offs clause, not the claim about overlapping priority areas. The Results (p. 8) report mixed outcomes across single-objective restoration allocations, and the Discussion (p. 14) explicitly describes trade-offs among restoration benefits and costs. (LLM, conf=0.91)

  cites [9] Strassburg, B. B. N. et al. Strategic approaches to restoring ecosystems can triple conservation gains and halve costs. Nat. Ecol. Evol. 3, 62–70 (2019). source

In the paper

“Linear programming identifies exact solutions to linear optimization problems 15,16 -unlike the heuristic algorithms that are more commonly used in conservation [12][13][14] , which identify feasible solutions of unknown optimality 17,18 .”

What the sources say

• ?Not checked — no full text of the sourcecites [15] Ando, A., Camm, J., Polasky, S. & Solow, A. Species distributions, land values, and efficient conservation. Science 279, 2126–2128 (1998). source
• ?Could not verify

  The citation is attached to the claim that heuristic algorithms are more commonly used in conservation. The Comparisons Between Ecosystem Services and Biodiversity section instead says this paper used integer programming; the Discussion calls its analyses heuristic in purpose, not its algorithms heuristic. Our copy does not establish how commonly conservation uses heuristic algorithms or whether their solutions have unknown optimality. (LLM, conf=0.76)

  cites [16] Naidoo, R. et al. Global mapping of ecosystem services and conservation priorities. Proc. Natl Acad. Sci. USA 105, 9495–9500 (2008). sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [17] Beyer, H. L., Dujardin, Y., Watts, M. E. & Possingham, H. P. Solving conservation planning problems with integer linear programming. Ecol. Modell. 328, 14–22 (2016). source
• ?Not checked — no full text of the sourcecites [18] Cabeza, M. & Moilanen, A. Design of reserve networks and the persistence of biodiversity. Trends Ecol. Evol. 16, 242–248 (2001). source

In the paper

“To estimate the potential carbon stocks that can accumulate in the long term in above-and belowground biomass after restoration, we used an approach commonly used in global estimates (for example, ref. 53 ).”

What the sources say

• Supported

  Section 3 describes biome-average carbon values as the most routinely used source of forest carbon stock data and applies them to estimate stocks across tropical countries. This supports the citation’s claim that the approach is commonly used in global estimates; the restoration application is the citing authors’ own use of it. (LLM, conf=0.90)

  cites [53] Gibbs, H. K., Brown, S., Niles, J. O. & Foley, J. A. Monitoring and estimating tropical forest carbon stocks: making REDD a reality. Environ. Res. Lett. 2, 045023 (2007). source

In the paper

“Although agricultural intensification can have detrimental effects on climate, biodiversity and human health 2,[35][36][37][38][39] , yields can often be increased without incurring these costs 37 .”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [2] IPCC. An IPCC Special Report on Climate Change, Desertification, Land Degradation, Sustainable Land Management, Food Security, and Greenhouse Gas Fluxes In Terrestrial Ecosystems (SRCCL) (World Meteorological Organization, 2019).
• Partly supported

  The Introduction and Soil compaction sections describe ways cattle-ranching productivity can increase while sparing natural areas, reducing emissions, or benefiting biodiversity. But the paper presents these as context-dependent possibilities, not as something that often occurs without the cited costs; the passages do not establish an absence of human-health costs. Page numbers are unavailable in our copy. (LLM, conf=0.82)

  cites [35] Latawiec, A. E., Strassburg, B. B. N., Valentim, J. F., Ramos, F. & Alves-Pinto, H. N. Intensification of cattle ranching production systems: socioeconomic and environmental synergies and risks in Brazil. Animal 8, 1255–1263 (2014). sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [36] Newbold, T. et al. Global effects of land use on local terrestrial biodiversity. Nature 520, 45–50 (2015). source
• Partly supported

  The discussion (p. 12) gives examples of yield-increasing practices that avoid greenhouse-gas penalties or reduce emissions, while the biodiversity discussion (p. 6) says higher yields can reduce impacts when natural habitats are spared. But the paper does not establish that yield increases often avoid human-health costs; its conclusion (p. 13) warns that high-yield systems can harm health without additional measures. (LLM, conf=0.86)

  cites [37] Balmford, A. et al. The environmental costs and benefits of high-yield farming. Nat. Sustain. 1, 477–485 (2018). sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [38] Garnett, T. et al. Sustainable intensification in agriculture: premises and policies. Science 341, 33–34 (2013). source
• Partly supported

  The Discussion (page not available) says increased yields can save land and potentially increase carbon storage. It also says those benefits may be offset by agricultural emissions and that the study cannot establish the sustainability of its scenarios. It therefore does not support the claim that yields can often be increased without climate, biodiversity, or human-health costs. (LLM, conf=0.84)

  cites [39] Erb, K.-H. et al. Exploring the biophysical option space for feeding the world without deforestation. Nat. Commun. 7, 11382 (2016). sourceExperimental — accuracy not yet measured

In the paper

“We find that restoring 15% of converted lands in priority areas could avoid 60% of expected extinctions while sequestering 299 gigatonnes of CO 2 -30% of the total CO 2 increase in the atmosphere since the Industrial Revolution.”

In the paper

“Although single-criterion solutions do not perform well for the other criteria, multicriteria solutions can deliver a substantial fraction of both sets of benefits simultaneously.”

In the paper

“At 15% restoration (scenario V in Fig. 3), this scenario would deliver 91% of the potential benefit for biodiversity and 82% of that for climate, while reducing costs by 27% compared to the biodiversity + climate scenario”

In the paper

“If focused on the mitigation of climate change, up to 335 ± 35 gigatonnes of CO 2 could be sequestered (Figs.2b, 3)-equivalent to 34% of the total increase in atmospheric CO 2 since the Industrial Revolution (about ad 1750).”

In the paper

“Across the main scenarios, carbon prices of US$10-15 per tonne of CO 2 would be sufficient to cover costs in targets up to 45% of global converted area (Extended Data Fig. 4), which could deliver climate mitigation benefits of as much as 702 ± 83 gigatonnes of CO 2 .”

In the paper

“At national levels, outcomes would be within 3% or less of the unconstrained global scenarios (scenario VIII in Fig. 3), whereas at landscape levels biodiversity benefits would drop by 12% only (scenario IX in Fig. 3), instead of 67% in the uniform scenario.”

In the paper

“Optimizing for both benefits simultaneously ('biodiversity + climate' scenario in Fig. 1d) would deliver 95% of the maximum biodiversity benefit and 89% of the maximum for climate change mitigation (scenario III in Fig. 3).”

In the paper

“In comparison with scenarios that uniformly constrain restoration to a fixed 15% of national or landscape units, implementing restoration in priority areas while maintaining current agricultural production via achievable yield increases would result in far greater environmental”

In the paper

“Converted areas within relatively intact tropical forests are also priorities for the mitigation of climate change, and South American and African shrublands are additional priorities for biodiversity (Fig. 1).”

In the paper

“Wetlands and forests are of the highest relative importance for biodiversity conservation (Fig. 4a) and the mitigation of climate change (Fig. 4b), respectively.”

In the paper

“Priority areas for restoration that focus solely on biodiversity, climate change mitigation or cost minimization (Fig. 1a-c) have different spatial patterns, which result in widely variable restoration outcomes.”

In the paper

“Benefits for the mitigation of climate change vary threefold (sequestration of 48-130 gigatonnes of CO 2 under 5% restoration) (Fig. 2b).”

In the paper

“Constraining targets so that all landscapes are restored by 15% (scenario VII in Fig. 3) would reduce biodiversity benefits by 67% and the benefits of climate change mitigation by 49%, while increasing costs by 92%.”

In the paper

“Applying the 15% restoration target at the national scale would result in a 28% reduction in benefits for biodiversity and 29% for climate while increasing costs by 52% (scenario VI in Fig. 3) in the multiple benefits scenario, when compared to the global unconstrained equivalent.”

In the paper

“Joint priority areas for biodiversity and climate are concentrated in wetlands and tropical and subtropical forests with high carbon stocks, high diversity and marked loss of natural habitat, and are generally located 10 in biodiversity hotspots 30 .”

What the sources say

• ?Not checked — no full text of the sourcecites [30] Myers, N., Mittermeier, R. A., Mittermeier, C. G., da Fonseca, G. A. & Kent, J. Biodiversity hotspots for conservation priorities. Nature 403, 853–858 (2000). source

In the paper

“Of 2,870 million hectares of converted lands we identified worldwide, we estimate that 54% were originally forests, 25% grasslands, 14% shrublands, 4% arid lands and 2% wetlands (Extended Data Fig. 5).”

In the paper

“The biodiversity-focused solution of the 15% target delivers 73% of potential climate-mitigation gains, whereas the climate-focused solution provides only 65% of the potential biodiversity gains.”

In the paper

“Up to 61% of the global priority areas (mostly in the tropics; red in Extended Data Fig. 8) would not be restored in these national-level scenarios, although they could potentially be targeted by international incentive schemes such as REDD+.”

In the paper

“Benefits for biodiversity, estimated as reductions in extinction debt, vary sixfold for the same area restored (the reduction in extinction debt for 5% restoration varies from 7 to 43%) (Fig. 2a).”

In the paper

“The spatial patterns for individual criteria (a-c) vary considerably, which highlights the role of joint optimizations (d, e) in capturing synergies.”

In the paper

“with relatively little variation among the five land-cover types: forests, 4.0% (a); grasslands, 1.7% (b); shrublands, 4.3% (c); wetlands, 1.2% (d); and arid areas, 2.6% (e).”

In the paper

“The results highlight the substantial variation in outcomes for the same area target, illustrated in a by the sixfold difference in outcomes for biodiversity (α) for the same 5% restoration target depending on the criteria chosen for the spatial allocation of restoration.”

In the paper

“The results highlight the substantial variation in the relative importance that each ecosystem type has depending on the objective(s) of restoration, which suggests that restoration initiatives aimed at multiple objectives should include several types of ecosystem.”

In the paper

“South America has the greatest extent of converted lands that are relatively evenly distributed in the top 50% of global priorities, whereas the Caribbean has the smallest extent of areas potentially available for restoration-but almost all of them are in the top 10% of global priorities.”

In the paper

“For instance, combining the retention of remaining natural ecosystems with the restoration of 30% of converted lands in priority areas would mitigate 71 ± 4% of current extinction debt while sequestering 465 ± 59 gigatonnes of CO 2 -equivalent to 49% of all of the CO 2 increase in the atmosphere since the Industrial Revolution.”

In the paper

“The unconstrained global scenarios are useful benchmarks and might support international incentive schemes such as REDD+ ('reducing emissions from deforestation and forest degradation' 22 ), yet involve some regions having high proportions of their converted lands prioritized for restoration.”

What the sources say

• ?Not checked — no full text of the sourcecites [22] Strassburg, B. B. N. et al. Impacts of incentives to reduce emissions from deforestation on global species extinctions. Nat. Clim. Chang. 2, 350–355 (2012). source

In the paper

“tropical forests (which make up most of the area of restored ecosystems in all but the 'minimize costs' scenarios) return to 90% of reference carbon stocks in 66 years and to >50% in the first 20 years (both median times) 29 .”

What the sources say

• ?Not checked — no full text of the sourcecites [29] Poorter, L. et al. Biomass resilience of Neotropical secondary forests. Nature 530, 211–214 (2016). source

In the paper

“a global analysis of priority areas for restoration has not yet been conducted and the interplay between multiple restoration objectives and biomes remains unknown.”

In the paper

“Our results confirm the vast potential contributions of restoration to addressing global challenges, while underscoring the necessity of pursuing these goals synergistically.”

In the paper

“Validation of the estimated original ecosystem type using data from 1992-2015 indicates high predictive accuracy (total root mean square error of 6.73%), consistent across all vegetation classes (Extended Data Fig. 6, Methods).”

In the paper

“Analyses within regions 9 , or subsets of habitat types 10 or ecoregions 11 , suggest restoration could be achieved at relatively low cost 12”

What the sources say

• ?Not checked — no full text of the sourcecites [12] Brooks, T. M. et al. Global biodiversity conservation priorities. Science 313, 58–61 (2006). source

In the paper

“We did not include the restoration of unconverted yet degraded natural ecosystems-which can contribute substantially to several global challenges 5 -because their restoration costs and benefits are poorly quantified.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [5] IPBES. The IPBES Assessment Report on Land Degradation and Restoration (IPBES Secretariat, 2018).

In the paper

“This lies at the lower end of mitigation cost options according to the Intergovernmental Panel on Climate Change (IPCC) 2 and below the 2019 market price in the EU trading scheme (US$25 per tonne of CO 2 equivalent).”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [2] IPCC. An IPCC Special Report on Climate Change, Desertification, Land Degradation, Sustainable Land Management, Food Security, and Greenhouse Gas Fluxes In Terrestrial Ecosystems (SRCCL) (World Meteorological Organization, 2019).

In the paper

“The concave shape of these trade-off curves suggests the potential for compromise options in the middle of the curves.”

In the paper

“These varied spatial patterns in turn underscore the need to adopt multicriteria approaches that incorporate several ecosystem types.”

In the paper

“The results show that the overall distribution of restoration would be very similar (total root mean square error of 13%), and differences in outcomes for biodiversity, carbon sequestration and costs are all within the margin of error for the estimates based on current land-use change (Extended Data Fig. 9).”

In the paper

“As most of these areas are in lower-income countries, the results reinforce the role that international cooperation mechanisms such as REDD+ can have in achieving cost-effective global outcomes through restoration.”

In the paper

“No primary data was collected and no sampling was performed”

In the paper

“These values suggest the potential for more ambitious restoration beyond the 15% Aichi Biodiversity Target 15 and highlight the substantial scope for a restoration approach implemented through integrated landscape management to provide marked environmental benefits while limiting conflicts with agriculture.”

What the sources say

• ?Not checked — no full text of the sourcecites [15] Ando, A., Camm, J., Polasky, S. & Solow, A. Species distributions, land values, and efficient conservation. Science 279, 2126–2128 (1998). source

In the paper

“Second, our approach to estimating the original vegetation cover might underestimate the original coverage of some ecosystems, although our estimates fall within ranges found in the literature 5 and validation analyses indicated high accuracy (Extended Data Fig. 6).”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [5] IPBES. The IPBES Assessment Report on Land Degradation and Restoration (IPBES Secretariat, 2018).

In the paper

“The experiments were not randomized and investigators were not blinded to allocation during experiments and outcome assessment.”

In the paper

“No statistical methods were used to predetermine sample size.”

In the paper

“No data were excluded from the analyses”

In the paper

“The findings can be reproduced using the datasets and codes developed, all either publicly available or available upon request”

In the paper

“Our potential and current carbon stock estimates (Extended Data Fig. 2b) also have intrinsic uncertainties that are combined when delta carbon values are calculated, and these uncertainties are probably underestimated given the unknown biases introduced by our extrapolation of biomass values from preserved areas to converted lands.”

In the paper

“Our quantification of potential carbon sequestration-similarly to other approaches (for example, that of the IPCC)-lacks an explicit temporal dimension and does not consider ecosystem feedbacks, but only changes in carbon stocks resulting from land-use change.”

In the paper

“which further highlights the importance of using multicriteria optimizations that take into account several benefits of restoration simultaneously.”

In the paper

“No data collection was performed, and blinding not applicable to the modeling approach used”

In the paper

“Second, our findings highlight that area alone is an ineffective metric for ensuring substantial biodiversity and climate mitigation outcomes, with up to sixfold variation in outcomes for the same restored area; targets should instead be oriented towards overarching outcomes, such as extinction avoidance and the mitigation of climate change.”

In the paper

“We focused exclusively on converted areas, but the restoration of degraded ecosystems that have not been fully cleared can also provide important benefits 5 .”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [5] IPBES. The IPBES Assessment Report on Land Degradation and Restoration (IPBES Secretariat, 2018).

In the paper

“Fourth, we show the complementary roles that different countries have in meeting overarching global targets, highlighting the benefits of international cooperation.”