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Abstract Peatlands store large amounts of carbon (C), a function potentially threatened by climate change. Peatlands composed of vascular cushion plants are widespread in the northern and central high Andes (páramo, wet and dry puna), but their C dynamics are hardly known. To understand the interplay of the main drivers of peatland C dynamics and to infer geographic patterns across the Andean regions, we addressed the following question: How do topography, hydrology, temperature, past climate variability, and vegetation influence the C dynamics of these peatlands? We summarize the available information on observed spatial and inferred temporal patterns of cushion peatland development in the tropical and subtropical Andes. Based on this, we recognize the following emerging patterns, which all need testing in further studies addressing spatial and temporal patterns of C accumulation: (1) Peatlands in dry climates and those in larger catchments receive higher sediment inputs than peatlands from wet puna and páramo and in small catchments. This results in peat stratigraphies intercalated with mineral layers and affects C accumulation by triggering vegetation changes. (2) High and constant water tables favor C accumulation. Seasonal water level fluctuations are higher in wet and dry puna, in comparison with páramo, leading to more frequent episodes of C loss in puna. (3) Higher temperatures favor C gain under high and constant water availability but also increase C loss under low and fluctuating water levels. (4) C accumulation has been variable through the Holocene, but several peatlands show a recent increase in C accumulation rates. (5) Vegetation affects C dynamics through species‐specific differences in productivity and decomposition rate. Because of predicted regional differences in global climate change manifestations (seasonality, permafrost behavior, temperature, precipitation regimes), cushion peatlands from the páramo are expected to mostly continue as C sinks for now, whereas those of the dry puna are more likely to turn to C sources as a consequence of increasing aridification.
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Pastoralism in the high tropical Andes: A review of the effect of grazing intensity on plant diversity and ecosystem services
Pastoralism is a land‐use system that involves the care and use of grazing livestock and has been more common in areas of low resource availability. In this review, we analyze the impact of pastoralism on biodiversity and ecosystem services across the tropical Andes. This region is the most extensive and populated tropical mountain region in the world and presents a high diversity of biomes, livestock types and management histories. Given that pastoralism is a main land use here, understanding its impacts is important for providing appropriate recommendations for sustainable management. LocationTropical Andes; Venezuela to the north of Argentina and Chile. MethodsTo understand these impacts, we performed a systematic literature search (August 2021) and obtained 103 articles. We created a conceptual framework to map how available research has contributed to our understanding of the main pastoral systems, their associated management strategies and the impact of different grazing intensities on vegetation cover/diversity and ecosystem services. ResultsWe found that research has focused on two leading pastoral systems in the region: bovines in the páramo biome of the northern Andes and camelids in the puna biome of the central Andes. We found important environmental impacts at high grazing intensities for both the puna camelid and páramo bovine pastoral systems, including a decrease in soil organic carbon and an increase in soil compaction, a decrease in above‐ground biomass, plant species richness, and graminoid cover, as well as clear changes in the growth‐form composition of vegetation. ConclusionsGiven these findings, we recommend coordinated research efforts using common methodologies, documenting current and previous land use, including stocking rates, and combining observational and experimental approaches to develop a more integrated understanding of pastoralism's impacts across this diverse and vulnerable region.
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- Award ID(s):
- 2209352
- PAR ID:
- 10567162
- Editor(s):
- Durigan, Giselda
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Applied Vegetation Science
- Volume:
- 27
- Issue:
- 3
- ISSN:
- 1402-2001
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1111/avsc.12791
