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It’s time to assign nonforested, nonagricultural lands a global designation

Published online by Cambridge University Press:  18 February 2025

David D. Briske Open the ORCID record for David D. Briske [Opens in a new window] ,
Lynn Huntsinger ,
Nathan F. Sayre ,
Peter F. Scogings Open the ORCID record for Peter F. Scogings [Opens in a new window] ,
Mark Stafford-Smith  and
Tungalag Ulambayar
David D. Briske*
Affiliation:
Ecology & Conservation Biology, Texas A&M University, College Station, TX, USA
Lynn Huntsinger
Affiliation:
Rangeland & Wildlife Management, University of California, Berkeley, Berkeley, CA, USA
Nathan F. Sayre
Affiliation:
Geography Department, University of California-Berkeley, Berkeley, CA, USA
Peter F. Scogings
Affiliation:
Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Scottsville, South Africa
Mark Stafford-Smith
Affiliation:
CSIRO, Land & Water, Canberra, ACT, Australia
Tungalag Ulambayar
Affiliation:
Zoological Society Luujin, Ulaanbaatar, Mongolia
*
Corresponding author: David D. Briske; Email: [email protected]
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Abstract

Earth’s land cover consists of forests, agricultural land, urban settlements and a large, heterogeneous category that includes deserts, grasslands, savannas, shrublands and tundra. This heterogeneous category has eluded a collective designation comparable to that of forests, which has contributed to its omission from multilateral programs and critical global initiatives. Potential designations for this land category – drylands, grasslands, grassy biomes, open ecosystems and rangelands – were evaluated for their relative advantages and disadvantages. Grassy biome is recommended as the most appropriate designation because it conveys a meaning that is distinct from forests, emphasizes that grasses often coexist with other plant growth forms and has great utility for use by multilateral organizations. However, the criteria of tree canopy cover >10% used by the Food and Agriculture Organization (FAO) to define forests represents a major obstacle to implementation of the grassy biome designation. This minimal canopy cover infringes on global savannas that occupy 20–25% of global land area. An assessment of the functional plant traits determining the shade and fire tolerance of savanna and forest trees indicates that a minimal tree canopy cover of 45% represents an ecologically appropriate demarcation between savannas and forests.

Topics structure

Topic(s)

Dryland ecosystem types

Subtopic(s)

Land use planning

Keywords

DrylandsForest classificationGlobal land assessmentGrassy biomesRangelands
Type
Perspective
Information
Cambridge Prisms: Drylands , Volume 2 , 2025 , e5
Creative Commons
Creative Common License - CCCreative Common License - BY
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.
Copyright
© The Author(s), 2025. Published by Cambridge University Press

Impact statement

Declaration of 2026 as the International Year of Rangelands and Pastoralists by the United Nations General Assembly provides an opportune occasion to promote a global designation for the nonforested, nonagricultural land category. We respectfully urge multilateral organizations and partner nations to adopt “grassy biomes” as a formal designation for this heterogeneous land category. The defining feature of this designation is a consistent cover of annual or perennial grasses throughout much of the year, including coexistence of other plant growth forms e.g., forbs, shrubs, succulents and scattered trees. The grassy biome designation would provide a more ecologically accurate distinction from forests than the one which is currently utilized. This would establish the foundation for development and implementation of a grassy biome resource assessment comparable to that of forest resource assessments that have been conducted by FAO for the past 70 years. Collectively, these resource assessments would provide valuable inventory data for approximately 75% of the Earth’s land surface and effectively support the aspirations and futures of its many peoples. Continued prioritization of forest assessments over those of the grassy biome can no longer be justified given the pressing challenges confronting Earth stewardship.

Introduction

Earth’s land cover broadly consists of forests, agricultural land, urban settlements and a large, heterogeneous category that includes deserts, grasslands, savannas, shrublands and tundra. This land category represents approximately 50% of the Earth’s land surface, which is 1.5 and 2.8 times greater than that of forests and agricultural land, respectively (Reid et al., Reference Reid, Galvin, Kruska, Galvin, Reid, Behnke and Hobbs2008; UNCCD, 2024). Various terms are used to describe these lands, including drylands, grasslands, grassy biomes, open ecosystems, grazing lands and rangelands. These are overlapping but nonidentical terms and each has multiple definitions that vary by author and application, specifically with reference to land use and land type. For example, a recent report by the UN Convention to Combat Desertification (UNCCD) used three terms – drylands, grasslands and rangelands – to describe this heterogeneous land category, with rangelands defined as a land use, rather than a land cover type (UNCCD, 2024). Moreover, these lands occur on all continents except Antarctica, spanning numerous cultures and languages which further contributes to this varied nomenclature (Figure 1).

Figure 1. Map illustrating spatial coverage of the proposed grassy biome category, including its representative biomes, in comparison to forests. Inset illustrates the aggregate coverage of the proposed grassy biome category (beige) relative to that of the forest land category (green) (modified from Olson et al., Reference Olson, Dinerstein, Wikramanayake, Burgess, Powell, Underwood, D’amico, Itoua, Strand, Morrison, Loucks, Allnutt, Ricketts, Kura, Lamoreux, Wettengel, Hedao and Kassem2001).

The absence of a single, globally recognized designation for these lands creates a major obstacle to their recognition, perceived value and stewardship (Johnsen et al., Reference Johnsen, Niamir-Fuller, Bensada and W-B2019; Parr et al., Reference Parr, te Beest and Stevens2024). For example, numerous multilateral organizations specifically attend to forests and agricultural land, and the Food and Agriculture Organization (FAO) has conducted regular global forest resource assessments for 70 years (Garzuglia, Reference Garzuglia2018). In contrast, comparable assessments have not been conducted for the heterogenous land category, and a substantial fraction is routinely misclassified as forest or degraded forest (Scogings, Reference Scogings2023; Parr et al., Reference Parr, te Beest and Stevens2024). In addition, this land category is not explicitly referenced in the U.N. Sustainable Development Goals, whereas two targets specifically invoke forests in Goal 15 – Life on Land. The limited recognition and value assigned to these lands have been described as a “case of benign neglect” in a U.N. report (Johnsen et al., Reference Johnsen, Niamir-Fuller, Bensada and W-B2019). Insufficient emphasis on these lands by multilateral organizations and member states obscures the value of 50% of the Earth’s land area to society and Earth stewardship (Stafford-Smith and Metternicht, Reference Stafford-Smith and Metternicht2021; Zhang et al., Reference Zhang, Tariq, Hughes, Hong, Wei, Sun, Sardans, Penuelas, Perry, Qiao, Kurban, Jia, Raimondo, Pan, Yang, Zhang, Li, Ahmed, Beierkuhnlein, Lazkov, Toderich, Karryeva, Dehkonov, Hisoriev, Dimeyeva, Milko, Soule, Suska-Malawska, Saparmuradov, Bekzod, Allin, Dieye, Cissse, Whibesilassie and Ma2023).

Declaration of 2026 as the International Year of Rangelands and Pastoralists by the United Nations General Assembly provides an opportune occasion to promote a global designation for this land category (IYRP, 2022). Adoption of a common designation by multilateral organizations and member states would promote recognition and stewardship at a level comparable to that of forests. Such a designation is not intended to replace the established names of ecological biomes – large geographical regions characterized by a distinct climate and biota that possess similar adaptations to that environment e.g., desert, grassland or forest – or regional nomenclature for specific vegetation types within this land category.

Potential land category designations

The heterogeneous land category, excluding agricultural lands and human settlements, represents the conceptual reciprocal of forests. Forests comprise diverse tree growth forms, including evergreen and deciduous species of varying stature, density and proportion, but they share a common appearance because the tree growth form remains dominant. In contrast, the heterogeneous land category is comprised of multiple plant growth forms, including grasses, forbs, shrubs, succulents and trees, in various combinations and proportions, but are not forests. The heterogeneous composition of vegetation in this land category has eluded a collective designation, so that specific vegetation types – grasslands, savannas, shrublands, deserts and tundra – are individually referenced.

We have chosen to use land cover, rather than land use, to assess land category designations because it implicitly acknowledges the diverse ecosystem services supplied and is most easily evaluated by multiple assessment procedures. However, functional plant traits are referenced to identify critical distinctions between land cover categories when information is available.

The definitions and relative advantages and disadvantages of dryland, grassland, grassy biome, open ecosystem and rangeland as appropriate designations for this land category are presented in Table 1. Grassland is the only designation that represents an ecological biome. Each of the designations has numerous and varied definitions so those that identify the most common descriptors and are referenced most frequently have been selected. Although some commonality exists among the five broad designations associated with this land category, they do not express synonymous meanings, and they all possess various advantages and disadvantages. Drylands, grasslands and rangelands received careful consideration given their extensive prior usage and recognition, but they were all determined to have major limitations as an effective designation.

Table 1. Definitions and advantages and disadvantages of five broad designations considered for the heterogeneous land category

Drylands are exclusively based on climatic criteria – an aridity index (annual precipitation/evapotranspiration) less than 0.65 – without specific reference to land cover. This designation is ecologically appropriate insofar as the representative biomes occur in drier climates than do forests, but the wettest portions of grassland, savanna and shrubland biomes exceed this aridity index with a mean annual precipitation of 1,000 mm (Whittaker, Reference Whittaker1975) (Figure 2). Moreover, drylands represent the domain of the UNCCD, which includes arable lands.

Figure 2. Correlation between biomes and mean annual temperature and precipitation across the globe. Area within the dotted lines represents a zone of biome uncertainty in which natural disturbance regimes may prevent the climatic potential from being realized (modified from Whittaker, Reference Whittaker1975).

Grasslands are widely envisioned as expansive treeless plains, which are most prominent in Asia, North America and South America. However, globally, grasses often coexist with shrubs, trees and succulent plants in various combinations and proportions. These heterogeneous vegetation types – shrub-steppe, shrublands and savannas – are not effectively represented by the grassland designation and grasslands are frequently misinterpreted as degraded forests, rather than having evolved with unique climates and natural disturbance regimes (Bond et al., Reference Bond, Woodward and Midgley2005; Davis, Reference Davis2016).

The term rangelands has been extensively used in Western range science for over a century, primarily in Australia, South Africa and the U.S., but global usage has been limited. Two notable exceptions are the use of rangelands by the International Year of Rangelands and Pastoralists (IYRP, 2022), which adopted terminology developed by the International Rangeland Congress (IRC, 1978). Adoption of the term rangelands was strongly influenced by members of the U.S. rangeland community, which convened the inaugural rangeland congress in Denver, Colorado in 1978.

Broad international usage of rangelands has been limited by several major challenges. First, it has a negative connotation relative to forests, which dates to the mid-19th century when western European scholarship erroneously interpreted rangelands as degraded forests (Davis, Reference Davis2016; Kumar et al., Reference Kumar, Pfeiffer, Gaillard, Langan, Martens and Scheiter2020). In this context, rangeland is a social classification that emphasizes marginal land, rather than an ecological classification based on land cover (Sayre, Reference Sayre2017). Second, rangeland is often understood as a land use, emphasizing forage and livestock production, rather than a land cover type (UNCCD, 2024). Range livestock production is vital to pastoral livelihoods, but rangelands also hold great value to Earth stewardship for climate regulation, biodiversity conservation and numerous cultural values (Briske and Coppock, Reference Briske and Coppock2023; Zhang et al., Reference Zhang, Tariq, Hughes, Hong, Wei, Sun, Sardans, Penuelas, Perry, Qiao, Kurban, Jia, Raimondo, Pan, Yang, Zhang, Li, Ahmed, Beierkuhnlein, Lazkov, Toderich, Karryeva, Dehkonov, Hisoriev, Dimeyeva, Milko, Soule, Suska-Malawska, Saparmuradov, Bekzod, Allin, Dieye, Cissse, Whibesilassie and Ma2023). Third, the rangelands designation carries colonial implications derived from its European origins and imposition on indigenous lands (Davis, Reference Davis2016). Finally, a comparable term for rangelands does not exist in most languages, so translation presents a major challenge.

Open ecosystems were also considered inappropriate because they were introduced to identify a specific portion of this land category – grasslands and savannas that occur in climates warm and wet enough to support closed forests but are not forests or anthropogenically degraded forests (Bond, Reference Bond2019). In these cases, the natural disturbance regimes of fire and grazing prevent the climatic potential from being expressed as forest (Figure 2). The term “open” may further marginalize this land category by suggesting that it has minimal value and that it is well suited for alternative land uses, e.g., afforestation, agriculture and renewable energy (Briske and Coppock, Reference Briske and Coppock2023). Open ecosystems have several alternative meanings in ecology and information networking.

A multi-term designation was also considered – grassland–rangeland–savanna – but its value for further promoting global recognition of this land category is questionable. The composite term “grasslands and rangelands” has several supporting arguments: (a) “grasslands” is familiar/recognizable across places and languages, and many people value them; (b) and “rangelands” encompass the various land cover types that aren’t grasslands; (c) the two together allow for the presence or the absence of livestock grazing; (d) they both have recognized bodies of scholarship (grassland ecology, rangeland ecology). However, the existing ambiguity and inconsistency of each term are potentially compounded by their combined use (Table 1).

Selected land category designation

Grassy biome was selected as the most appropriate designation for this land cover category. It is characterized by a grass cover that varies from open grasslands to savannas with up to 60% tree cover that is maintained by natural disturbance regimes of grazing, drought and fire (Bond et al., Reference Bond, Woodward and Midgley2005; Parr et al., Reference Parr, Lehmann, Bond, Hoffmann and Andersen2014). Original usage of the term was similar to that of open ecosystems in that it was intended to establish tropical grasslands and savannas as being distinct from forests (Bond, Reference Bond2019) (Figure 2). However, recent usage of grassy biome indicates that it is more comprehensive than those of the topical systems originally identified.

We recommend that grassy biome be used to broaden the scope of the grassland biome, both tropical and temperate, by recognizing that grasses frequently coexist with other plant growth forms e.g., forbs, shrubs, succulents and scattered trees. The defining feature of this designation is a consistent cover of annual or perennial grasses throughout much of the year. In this context, grassy biomes also include tundra because grasses and grass-like sedges are an important land cover. The functional plant traits supporting high tolerance to drought, grazing and fire and low tolerance to prolonged shade make deserts, grasslands, savannas and shrublands more similar to each other than to forests (Bond et al., Reference Bond, Woodward and Midgley2005; Parr et al., Reference Parr, Lehmann, Bond, Hoffmann and Andersen2014).

The evolutionary history of the grassy biome has been well established in the palaeoecological record (Jacobs et al., Reference Jacobs, Kingston and Jacobs1999). They initially became widespread in the early to mid-Tertiary Period 30–60 MYA. Savannas and grasslands further expanded in the late Miocene Epoch 15 MYA as forests began to open in response to a drier and more seasonal climate. Herbivores coevolved with expanding grass-dominated biomes by adapting functional traits that facilitated grazing rather than browsing strategies.

A proposed definition for the grassy biome designation follows along with the current FAO definition for forests.

Grassy biome – Land spanning more than 0.5 ha with a minimum of 10% cover of annual or perennial grass for at least 2 months of the year (Lund, Reference Lund2007) and a canopy cover of trees greater than 5 m that does not exceed 45%. This land category includes grasslands, savannas, shrublands, deserts and tundra while cultivated, irrigated and agroforestry lands are excluded.

Forest – Land spanning more than 0.5 ha with trees higher than 5 m and canopy cover more than 10%, or trees able to reach these thresholds in situ. It includes young natural stands and forest nurseries but not forests on agricultural or urban lands (FAO, 2020).

We acknowledge that entirely unique designations may exist for this heterogeneous land category. A novel term that emerged from our deliberations was “terravista”. It is derived from the Latin word’s terra (“land”) and vista (“view”). “Terravista” expresses a feature common to all the biomes in this land category: namely, open visibility over long distances for a human on the ground. This effectively captures the reciprocal relation of “terravista” to forests because even though savannas have trees, the sparse densities permit ready visibility. While this may suggest a purely structural definition, we intend “terravista” to encompass the functional attributes associated with the grassy biome.

Forest–grassy biome demarcation

The recommended grassy biome category exhibits vast overlap with forest land based on FAO’s criterion of tree canopy cover >10% (Garzuglia, Reference Garzuglia2018; Scogings, Reference Scogings2023). This criterion was originally derived from the UNESCO report “International Classification and Mapping of Vegetation” (UNESCO, 1973), which defined “closed” forest as having interlocking canopies and “woodlands” as having a canopy cover >40%. The 1980 FAO forest resources assessment also referenced “open” and “closed” forests as having canopy covers of 10–40% and >40%, respectively (Garzuglia, Reference Garzuglia2018). However, the 2000 forest resources assessment eliminated the open and closed forest classifications and applied the minimum 10% canopy cover criterion to all forests. Modification of this important criterion appears to have been arbitrarily made without clear ecological or socioeconomic justification and it has received substantial criticism (Veldman et al., Reference Veldman, Overbeck, Negreiros, Mahy, Le Stradic, Fernandes, Durigan, Buisson, Putz and Bond2015; Scogings, Reference Scogings2023).

This canopy cover criterion greatly infringes on savannas, which occupy 20–25% of global land area (Scogings, Reference Scogings2023). Savannas are characterized by a continuous cover of C4 grasses that are interspersed with trees of varying density and canopy cover. Savannas typically occur in tropical and subtropical regions characterized by mean annual temperature >10 °C and mean annual precipitation of 200–2700 mm, which is distributed in distinct wet-dry seasons (Stevens et al., Reference Stevens, Bond, Feurdean and Lehmann2022). However, most savannas occur in a narrower range of mean annual precipitation of 400–1600 mm (Scogings, Reference Scogings2023). Savannas are of ancient origin and are maintained by interactions among climate, fire and grazing (Bond et al., Reference Bond, Woodward and Midgley2005). These disturbances enable grassy biomes to extend into climatic zones capable of supporting forests and long-term variation among these variables is known to have modified grassy biome–forest boundaries (Whittaker, Reference Whittaker1975; Staver et al., Reference Staver, Archibald and Levin2011) (Figure 2). However, this does not imply that forests can occupy major portions of these grassy biomes when these disturbances are lessened.

The distinction between savannas and forests is dependent upon the functional plant traits that determine shade and fire tolerance, in addition to structural criteria (Ratnam et al., Reference Ratnam, Bond, Fensham, Hoffmann, Archibald, Lehmann, Anderson, Higgins and Sankaran2011). The amount of canopy shade at which sun-tolerant savanna tree seedlings are replaced by shade-tolerant forest trees is considered a “deep shade” threshold (Charles-Dominique et al., Reference Charles-Dominique, Midgley, Tomlinson and Bond2018; Pilon et al., Reference Pilon, Durigan, Rickenback, Pennington, Dexter, Hoffmann, Abreu and Lehmann2021). This threshold occurs at a leaf area ratio (LAR, leaf area/ground area) of 1.0–1.5, which coincides with a tree canopy cover of approximately 40–45% (Martens et al., Reference Martens, Breshears and Meyer2000; Duursma and Mäkelä, Reference Duursma and Mäkelä2007). A second critical threshold, the “fire suppression” threshold, occurs when grass cover and production are insufficient to support frequent ground fires that are necessary to minimize tree establishment and maintain grass dominance (Ratnam et al., Reference Ratnam, Bond, Fensham, Hoffmann, Archibald, Lehmann, Anderson, Higgins and Sankaran2011). This threshold occurs at a LAR of 1.0 and C4 grasses that are characteristic of tropical savannas are greatly suppressed at a LAR > 1.5 (Charles-Dominique et al., Reference Charles-Dominique, Midgley, Tomlinson and Bond2018; Pilon et al., Reference Pilon, Durigan, Rickenback, Pennington, Dexter, Hoffmann, Abreu and Lehmann2021). These critical thresholds occur at a minimal tree canopy cover of approximately 40–45% which directly challenges the validity of the 10% canopy cover criterion used by FAO to define forests.

The adverse consequences of the 10% tree canopy cover criterion are highlighted in the FAO report entitled the “first global assessment of trees and forests in drylands”, which provides a forest-centric representation of drylands (FAO, 2019). The assessment indicates that 18% of drylands are forested, with 50 and 66% having a canopy cover >70% and 40%, respectively. However, savannas, which were not acknowledged in the assessment, likely comprise much of these dryland forests (Scogings, Reference Scogings2023). The assessment further indicated that woodlands, including shrublands, comprise 10% of drylands and that “other lands”, including barren lands and grasslands represent 28% and 25%, respectively (FAO, 2019). In contrast, the “thematic report on rangelands and pastoralists” conducted by the UNCCD describes rangelands as being comprised of deserts (35%), tropical grasslands and savannas (26%) temperate grasslands and savannas (13%) and three other minor vegetation types, in addition to tundra (15%) (UNCCD, 2024). The recommended grassy biome designation is intended to minimize these inconsistencies among multilateral organizations by collectively representing all major vegetation types with a grass cover (Figure 2).

We acknowledge that the grassy biome designation possesses limitations and ecological exceptions, but it is intended to serve as a critical administrative instrument more than an ecological concept. Consider that “forest” serves as an effective land cover designation even though forests differ greatly in structure, function, management and value. Therefore, we suggest that the grassy biome designation be interpreted in a similar manner to preclude ecological limitations and exceptions from obscuring the critical need for greater recognition and assessment of this land category.

Recommendations

We respectfully urge multilateral organizations, specifically FAO and UNCCD, to adopt the following two recommendations in support of IYRP 2022. First, adopt “grassy biomes” as a formal and universal designation for heterogeneous lands not included in forests, agricultural land and urban settlements to ensure that they receive comparable recognition and value to that of forests. Second, revise the 10% tree cover criterion for the definition of forests to a minimal value of 45% so that global savannas and shrublands are appropriately assigned to the grassy biome category. Establishment of an appropriate tree cover criterion will require careful evaluation of ecological, socioeconomic and land classification considerations.

Adoption of these recommendations would establish the foundation for the development and implementation of a grassy biome resource assessment that would be comparable to that of forest assessments, which have been conducted for the past 70 years. These combined assessments would encompass 75% of the Earth’s land surface and provide valuable inventory data in support of Earth stewardship. For example, a more comprehensive and quantitative inventory of grassy biomes would directly support the recent initiative launched by UNCCD to address the complex challenges confronting conservation, management and restoration of this land category and better support the aspirations and futures of its many peoples (Herrera Calvo and Alexander, Reference Herrera Calvo and Alexander2024). Continued prioritization of forest assessments over those of grassy biomes can no longer be justified given the pressing challenges confronting Earth stewardship and human well-being (FAO, 2019; Lewin et al., Reference Lewin, Murali, Rachmilevitch and Roll2024).

Open peer review

For open peer review materials, please visit https://doi.org/10.1017/dry.2025.2

Acknowledgements

The constructive comments of two peer reviewers are greatly acknowledged.

Author contribution

Conceptualization and writing of initial draft: D.D.B.; Graphics selection and modification: L.H.; Review, editing and development of alternative designation: N.F.S.; Development of savanna-forest boundary content: P.F.S.; Support of designation assessment and final editing: M. S-S and T.U.

Financial support

No financial resources supported this work.

Competing interest

The authors have no competing interests to declare.

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Figure 0

Figure 1. Map illustrating spatial coverage of the proposed grassy biome category, including its representative biomes, in comparison to forests. Inset illustrates the aggregate coverage of the proposed grassy biome category (beige) relative to that of the forest land category (green) (modified from Olson et al., 2001).

Figure 1

Table 1. Definitions and advantages and disadvantages of five broad designations considered for the heterogeneous land category

Figure 2

Figure 2. Correlation between biomes and mean annual temperature and precipitation across the globe. Area within the dotted lines represents a zone of biome uncertainty in which natural disturbance regimes may prevent the climatic potential from being realized (modified from Whittaker, 1975).

Author comment: It’s time to assign nonforested, nonagricultural lands a global designation — R0/PR1

Published online by Cambridge University Press:  18 February 2025
DOI: https://doi.org/10.1017/dry.2025.2.pr1 [Opens in a new window]
David D. Briske [Opens in a new window] Texas A&M University, United States
Revision round: 0
Role: author

Comments

No accompanying comment.

Review: It’s time to assign nonforested, nonagricultural lands a global designation — R0/PR2

Published online by Cambridge University Press:  18 February 2025
DOI: https://doi.org/10.1017/dry.2025.2.pr2 [Opens in a new window]
Jeffrey Herrick [Opens in a new window] Range Management Research Unit, USDA Agricultural Research Service, United States
Date of review:  28 October 2024
Revision round: 0
Role: reviewer
Recommendation/decision: minor-revision

Conflict of interest statement

Reviewer declares none.

Comments

The manuscript argues that “drylands” be designated as class of land that is non-forested. Given the name of the new journal, it would seem to be an appropriate topic for a “perspectives” paper, and one that would likely generate discussion.

However, if the authors’ goal is to convince the governing bodies of the UNCCD and/or FAO to adopt a decision that results in allocation of resources necessary to write a report, they may wish to consider a term that is not already widely used as shorthand for the land that literally defines one of the conventions (arid, semi-arid and dry subhumid for the UNCCD). This climatic definition of “drylands”, in addition to being widely used, also has the benefit of being consistent with the word (“dry – lands”). And as the authors note, there are quite a number of grassland, shrubland and savanna ecosystems that are not, in fact “dry”, either because of climate, or landscape position and soils. These include sub-tropical grasslands in the southeast United States, wet meadows in temperate regions of Asia, Europe and North and South America, and some tropical pasture ecosystems in South America, among others. And then there’s tundra (123-127).

Furthermore, given the fact that this is a relatively new journal that, I would assume, hopes to attract as many submissions as possible, it may not be particularly strategic to promote an article that would seem to constrain future submissions to non-cultivated lands. A number of well-established journals already cover arid regions, and grassland, savanna and shrubland ecosystems. This new journal would seem uniquely titled to attract submissions that address the wicked challenges that confront the sustainable management of all drylands, including land conversion, abandonment and restoration. All of these topics require a definition of “drylands” that is not constrained by current or potential land cover. This is particularly critical as we consider the lives and livelihoods of those populations that the scientific community hopes to support, as well as the wildlife populations that depend on drylands for their continued existence. This approach could also solve the “tundra” issue, given the dominance of shrubs, grasses and grass-like species (e.g. sedges), in addition to lichens and mosses, which also occur in warmer and more arid systems.

Both challenges (UNCCD and journal) could be addressed by naming the proposed designation “grassland, savanna and shrubland” (or, in order of increasing woody biomass, “grassland, shrubland and savanna”). There have been several publications, and at least one monitoring manual, that have used some variation of this designation to refer to the types of land addressed by the manuscript.

Regardless of the term selected there are several other issues that could be helpfully considered by the authors.

- Is the definition to be based on current or potential vegetation (see FAO’s, for example)?

- If potential, under current or future climate conditions?

- Why “specifically FAO” (line 203) given that UNCCD is the drylands convention? Good arguments can be made for either, or perhaps both together as collaboration across the two institutions continues to increase?

- Why 45%, and not 40% as the upper limit for savannas, since the latter has already been widely used as the upper limit for “open forests”? New designations are challenging enough. New designations with new cutoffs are harder still.

Finally, somewhere in the manuscript it may be helpful to indicate whether or not the authors expect that the definition of “forest” will need to be modified for consistency with the new designation, regardless of what it is named. And perhaps discuss how overlapping definitions could be helpful to the extent that it results in reports that are more likely to be relevant to managers and policymakers. These individuals rarely have the luxury of setting boundaries at a specific cover threshold (whether 10, 40 or 45%). A 30-35% overlap is more likely to ensure that at least one of the reports would be relevant to their mandates, provided that the report recognizes the different management requirements and ecosystem services associated with different levels of tree cover. For example, in the US, while the different thresholds used by NRCS, BLM and USFS can be used to almost instantly spark an intense debate among staff associated with different agencies, these debates are rarely as inspired when they occur within an agency, as each agency seems to find that its definition generally, suits its needs.

Review: It’s time to assign nonforested, nonagricultural lands a global designation — R0/PR3

Published online by Cambridge University Press:  18 February 2025
DOI: https://doi.org/10.1017/dry.2025.2.pr3 [Opens in a new window]
Reviewer_1
Date of review:  08 November 2024
Revision round: 0
Role: reviewer
Recommendation/decision: major-revision

Conflict of interest statement

Reviewer declares none.

Comments

I revised the paper entitled “It’s Time to Assign Non-forested, Non-agricultural Lands a Global Designation” by Briske et al. I like the idea of the perspective and think it is highly relevant to discuss this issue. I have myself devoted a bit of time on thinking about this in the past and I like having some thoughts represented in the format of a perspective. That said, the perspective is kind of flat from my point of view. Authors do not dissect the problem thoroughly and simply make one opinion. While I disagree with their conclusion, I think the problem is not that, but the lack of analysis and convincing arguments on their rationale. Being this a perspective, I think Authors fail on thinking why we are using words as we are using them and they do not fully analyze pros and cons of their proposal.

First, regardless of their conclusion, I miss a lot some exercise of making the reader understand how we are classifying land cover types and the challenges it entails. A bit of info about why authors think the problem of not categorizing properly non forest, non agricultural landscapes would be interesting. According to the reading it seems authors think it is a matter of laziness however, classifying land cover types is complex task. I see at least 3 potential planes of discussion emerging from these problematics which are not commented on the paper:

a) What is the categorization aimed for, land cover type or land use? Undistinguishing about these 2 categories is problem contaminated from the very base of the definition. The dichotomy, for example between rangeland and grassland is mostly on whether you are using it or not; it happens the same with savannahs and dehesas, for example. One disadvantage mentioned in Table 1 for rangeland is that “References both land use and land cover”. It is true but, does not farmlands or cultivated lands suffer the same problem? Is not this actually a pros? Up to which point we should consider an artificial land a land cover type? Is the use important? A tree plantation is a forest? All this is fruitful, intriguing and unresolved discussion that is virtually ignored in the paper, making the feeling on the reader (that realizes about it) that authors are oversimplifying the problematic.

b) After thinking about it during many years one of the conclussions I got is that shrubs and grasses are technically difficult to classify as land cover. Indeed many models used for land cover attribution fail specifically for shrublands and grasslands. Maybe that is the reason why forests are much better represented (as agreement on them is more solid). I wonder what authors think about how this problem affects their proposed definition. Actually authors say grassland is not appropriate because in grasslands there are shrubs and tree companions; but is not this true for all land cover types? Where are the limits is the key to be discussed. Actually, one possible solution to this discussion is on the “use” we do of the land; which connects with problem 1.

c) In general one major problem lies on the fact that this land category is at least 3 categories (from my point of view): Savannahs (which you’ll need to define because the tree cover is not the only determinant; there are sites with tree cover ranging that of savannahs in the boreal zone; are those savannahs?); Grasslands; and shrublands (on this later existing different types of shrublands like the bushvelds of south africa similar to forests, vs the xerophytic shrublands and mediterranean maquias; each with their own problematics on being resolved from the air). Why not separating them? What is the added value of putting them all in the same term if they have structural, functional and socio-economic features that are completely different and, also they are going to be managed in completely different ways.

Second, the decision chosen I think it is as subjective and any other. I understand this do not invalidate the paper (as part of the subjectivity should be present in a piece like this); however I think the decision taken is too much arbitrary, not realistic and quite debatable. At the least, the possible problems should be much better highlighted. Here my opinion in case it helps to anticipate potential critiques:

- Sometimes authors criticize a nomenclature due to one reason and then they use the same reasoning for supporting another (e.g., terravista is bod because it is only structurally based; line 144-146) but grassland is good just because of this. In consistency on supporintg the ideas leads to a feeling for weaknesses in their propositions. For example, the same authors acknowledge on their proposition of using drylands that some areas could be misclassified (lines 121-123: “The wettest portions of grassland, savanna, and shrubland biomes exceed a mean annual precipitation of 1,000 mm, but this limited area represents a minor exception to the dryland’s designation”).

- Authors also propose re-define the climatic dryland definition to use it only as a land cover type (line 125-127); which would mean ignoring systematically all forests of drylands and re-define the basis of several global political movements and pannels such as the pannel UNCCD pannel for combatting desertification (desertification is based on dryland definition and includes also agrosystems in drylands). Equaling dryland to open ecosystem is adding more confusion, on my view than resolving the problem.

- The same obscureness that is argued for the necessity to designate these areas (in lines 1-57) is present in the definition of drylands as we do not know whether authors refer to grassland, shrubland or savannahs; both having completely different functional, structural and socio-economic features. The discussion of whether they should be collectively named or separated is also absent in the paper. Why using a single name for savannahs and shrublands; aren’t they totally different in all structural and functional aspects? Are not humans using them differently?

- Advantages and disadvantages in table 1 are also quite debatable. For example the disadvantage of open ecosystem: ““open” may suggest availability for alternative land uses, e.g., tree planting, agriculture and renewable energy generation”; is arguably an opinion and is confounded by the dichotomy use vs land cover type I mentioned above.

I agree in general with the savannah-forest discussion (lines 149-200)

Minor points:

Lines till 57: Fine. I agree, lot of earth cover not recognized

Line 91-92: “grasses often coexist with shrubs, trees, and succulent plants in various combinations and proportions” is not this true for all land cover types?

Line 139-146. Is not this open land?

Recommendation: It’s time to assign nonforested, nonagricultural lands a global designation — R0/PR4

Published online by Cambridge University Press:  18 February 2025
DOI: https://doi.org/10.1017/dry.2025.2.pr4 [Opens in a new window]
Laura Yahdjian University of Buenos Aires, Argentina
Date of review:  20 November 2024
Revision round: 0
Role: Handling Editor
Recommendation/decision: minor-revision

Comments

I am writing to you regarding Manuscript DRY-2024-0025 entitled “It’s Time to Assign Non-forested, Non-agricultural Lands a Global Designation” which you submitted to Drylands as a Perspective Article. Based on the reviewers’ comments, I am requesting that you undertake a revision of your manuscript. Both reviews were very positive, but they also raised concern about the proposal to use Drylands for non-forested and non-agricultural lands and the arguments supporting it. I agree with them that further discussion is needed. The reviewer’s comments are included at the bottom of this letter. I hope that we will be able to accept the manuscript for publication once of these revisions are satisfactory completed.

Decision: It’s time to assign nonforested, nonagricultural lands a global designation — R0/PR5

Published online by Cambridge University Press:  18 February 2025
DOI: https://doi.org/10.1017/dry.2025.2.pr5 [Opens in a new window]
Osvaldo Sala Arizona State University, United States
Revision round: 0
Role: Editor in Chief
Recommendation/decision: minor-revision

Comments

No accompanying comment.

Author comment: It’s time to assign nonforested, nonagricultural lands a global designation — R1/PR6

Published online by Cambridge University Press:  18 February 2025
DOI: https://doi.org/10.1017/dry.2025.2.pr6 [Opens in a new window]
David D. Briske [Opens in a new window] Texas A&M University, United States
Revision round: 1
Role: author

Comments

12/16/2024

Dear Editor-in-Chief Sala:

The opportunity to develop a revised manuscript is greatly appreciated. We have carefully considered the reviewer comments and have addressed them in the attached rebuttal file. Incorporation of these changes has greatly improved the clarity and impact of the perspective.

Two files of the revision have been attached. One includes track changes and these changes have been incorporated in the other (clean file).

Sincerely

David Briske

Review: It’s time to assign nonforested, nonagricultural lands a global designation — R1/PR7

Published online by Cambridge University Press:  18 February 2025
DOI: https://doi.org/10.1017/dry.2025.2.pr7 [Opens in a new window]
Jeffrey Herrick [Opens in a new window] Range Management Research Unit, USDA Agricultural Research Service, United States
Date of review:  24 January 2025
Revision round: 1
Role: reviewer
Recommendation/decision: accept

Conflict of interest statement

Reviewer declares none.

Comments

The manuscript can serve as a provocative conversation starter. It makes the important point that the value and extent of non-forested ecosystems is often underappreciated and that one way to increase awareness of them, and to focus attention on them, is through a revision of definitions. All of the questions below are, to a greater or lesser extent at this point, rhetorical. I look forward to seeing and hearing responses to the manuscript from the broader community.

• Is it necessary for “forests” to be restricted to >40 or 45% tree cover if

“grassy biomes” are to include land with less than this threshold? The probability of adopting a new class of land for reporting and investments through the multilateral negotiation process is not high. The challenge of convincing international bodies to reduce the scope of an existing class would seem orders of magnitude harder, for both technical and political reasons.

• It may be helpful to propose a theory of change, including how and why key stakeholder groups might be convinced to support the proposed definition.

• Unclear why 45% was selected instead of 40%, which has a history of acceptance as “closed canopy” (lines 199-200) and the critical thresholds cited (223 ff) are for “40-45%”. Why not start with a number for which there is at least some agreement?

• There is no simple answer and if the primary objective of the article is to stimulate discussion, I’m not sure that it’s necessary to address any of the questions below at this time, but I am guessing that other readers will, as I did, run through the grassy biomes of the world and in so doing, may ask one or more of the following questions:

Where do tundra and especially shrublands fit into this definition? And particularly shrublands that support less than 10% grass cover in their undegraded state, and those that due to degradation no longer support 10% grass cover? How is 10% grass cover defined? Average? At least 1 year in 5? Or 10? Median? The mind flies among different soils in possibly grassy biomes throughout the world. The diversity one sees from the window while driving from Adelaide to Darwin, Lubbock to Los Angeles, from the center of the southern border of Mongolia to its northern frontier, west across Inner Mongolia to China’s western border, from La Paz south into the Salar and from the Skeleton Coast to the brush and tree-invaded grasslands of northern Namibia. And East Africa, where one of the best indicators of rangeland degradation is the replacement of cattle by goats by camels– another region where the proportion of land that would meet the definition has visibly declined in the past decade.

• Where do the new tools that have already created their own definitions fit in? Geospatial practitioners are already developing the next generation of tools to focus attention on many parts of the “grassy biome”. Examples include “PastureWatch”, “Rangelands.app” and others. Would at least an acknowledgement that these sites are getting thousands (at least – I’ve not checked their stats) of hits be relevant? Might it make sense to include any implicit or explicit definitions applied by these sites?

• Perhaps provide a citation for the the “multi-term” designation of grassland-rangeland-savanna? I’ve heard of “grassland, shrubland and savanna”, but not the former. If either or both are included it may make sense to add to Table 1 though, again, I think it’s up to the authors and editor to decide what level of detail is appropriate given the format.

• Grassy biome definition, again. Line 152: up to 60% tree cover. Line 179: 45% unless I’m missing something.

Recommendation: It’s time to assign nonforested, nonagricultural lands a global designation — R1/PR8

Published online by Cambridge University Press:  18 February 2025
DOI: https://doi.org/10.1017/dry.2025.2.pr8 [Opens in a new window]
Laura Yahdjian University of Buenos Aires, Argentina
Date of review:  02 February 2025
Revision round: 1
Role: Handling Editor
Recommendation/decision: accept

Comments

Thank you for your efforts in improving the manuscript based on the reviewers' suggestions. Although a new revision is not formally required, the reviewer made several comments and asked questions that could be used to open the discussion in the article. I leave it to the authors to decide whether they wish to take advantage of this opportunity to incorporate these ideas.

Decision: It’s time to assign nonforested, nonagricultural lands a global designation — R1/PR9

Published online by Cambridge University Press:  18 February 2025
DOI: https://doi.org/10.1017/dry.2025.2.pr9 [Opens in a new window]
Osvaldo Sala Arizona State University, United States
Revision round: 1
Role: Editor in Chief
Recommendation/decision: accept

Comments

No accompanying comment.