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Functional response of U.S. grasslands to the early 21st-century drought
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Grasslands across the United States play a key role in regional livelihood and national food security. Yet, it is still unclear how this important resource will respond to the prolonged warm droughts and more intense rainfall events predicted with climate change. The early 21st-century drought in the southwestern United States resulted in hydroclimatic conditions that are similar to those expected with future climate change. We investigated the impact of the early 21st-century drought on aboveground net primary production (ANPP) of six desert and plains grasslands dominated by C4 (warm season) grasses in terms of significant deviations between observed and expected ANPP. In desert grasslands, drought-induced grass mortality led to shifts in the functional response to annual total precipitation (PT), and in some cases, new species assemblages occurred that included invasive species. In contrast, the ANPP in plains grasslands exhibited a strong linear function of the current-year PT and the previous-year ANPP, despite prolonged warm drought. We used these results to disentangle the impacts of interannual total precipitation, intra-annual precipitation patterns, and grassland abundance on ANPP, and thus generalize the functional response of C4 grasslands to predicted climate change. This will allow managers to plan for predictable shifts in resources associated with climate change related to fire risk, loss of forage, and ecosystem services.
Key words: climate change; desert; extreme events; grassland production; invasive species; plains; precipitation variability; resilience; warm drought.
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Funding Announcement: 2023 Shade Your Stream Grant Program
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Streambank Restoration Funding | AL, GA, KY, MS, NC, TN & VA.
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Funding for TN Partners | Riparian Restoration | Submission deadline: June 15
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The submission period for the TRBN's 2021 Tennessee Shade Your Stream funding cycle is now open. The purpose of this grant opportunity is to provide technical and financial assistance to TRBN partners in the implementation of an educational riparian restoration project within the Tennessee River Basin geography across the state of Tennessee.
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Future climate change driven sea-level rise: secondary consequences from human displacement for island biodiversity
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Sea-level rise (SLR) due to global warming will result in the loss of many coastal areas. The direct or primary effects due to inundation and erosion from SLR are currently being assessed; however, the indirect or secondary ecological effects, such as changes caused by the displacement of human populations, have not been previously evaluated. We examined the potential ecological consequences of future SLR on >1,200 islands in the Southeast Asian and the Pacific region. Using three SLR scenarios (1, 3, and 6 m elevation, where 1 m approximates most predictions by the end of this century), we assessed the consequences of primary and secondary SLR effects from human displacement on habi- tat availability and distributions of selected mammal species. We estimate that between 3–32% of the coastal zone of these islands could be lost from primary effects, and consequently 8–52 million people would become SLR refugees. Assuming that inundated urban and intensive agricultural areas will be relocated with an equal area of habitat loss in the hinterland, we project that secondary SLR effects can lead to an equal or even higher percent range loss than primary effects for at least 10–18% of the sample mammals in a moderate range loss scenario and for 22–46% in a maximum range loss scenario. In addition, we found some species to be more vulnerable to secondary than primary effects. Finally, we found high spatial variation in vulnerability: species on islands in Oceania are more vulnerable to primary SLR effects, whereas species on islands in Indo-Malaysia, with potentially 7–48 million SLR refugees, are more vulnerable to secondary effects. Our findings show that primary and secondary SLR effects can have enormous consequences for human inhabitants and island biodiversity, and that both need to be incorporated into ecological risk assessment, conservation, and regional planning.
Keywords: conservation priorities, extinction risk, global change, human migration, human settlements, Indo-Malaysia, insular biodiversity, range contractions, sea-level change
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Future collapse: how optimistic should we be?
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1st paragraph: Prof. Kelly FRS is optimistic about the chances of avoiding a collapse, but sadly we find his arguments entirely unpersuasive. For example, have Malthus (or we) really been wrong about food security? Roughly 850 million people are seriously undernourished (lacking sufficient calories) today, and perhaps 2 billion are malnourished (lacking one or more essential nutrients) [1]. When Malthus lived, there were only about 1 billion people on the planet. We agree that there are many things that could be done to feed today’s population of 7.1 billion, or even perhaps over 9 billion in 2050. Many of them (e.g. limiting waste) have been discussed for 50 years with little sign of progress. We do not think any serious analyst doubts that, if it were equitably distributed, today’s food production could nourish everyone adequately. Equally, we know of no serious analyst who believes such distribution is likely in the future. The concern is that climate disruption combined with other problems with the agricultural system will make it impossible to feed an ever larger future population, even if equal distribution were achieved. That concern is reinforced by the recent observation that, even before the likely heavy impacts of climate disruption on agriculture appear, production is failing to keep pace with projected needs [2].
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Future hotspots of terrestrial mammal loss
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Current levels of endangerment and historical trends of species and habitats are the main criteria used to direct conservation efforts globally. Estimates of future declines, which might indicate different priorities than past declines, have been limited by the lack of appropriate data and models. Given that much of con- servation is about anticipating and responding to future threats, our inability to look forward at a global scale has been a major constraint on effective action. Here, we assess the geography and extent of projected future changes in suitable habitat for terrestrial mammals within their present ranges. We used a global earth-system model, IMAGE, coupled with fine-scale habitat suitability models and parametrized accord- ing to four global scenarios of human development. We identified the most affected countries by 2050 for each scenario, assuming that no additional conservation actions other than those described in the scenarios take place. We found that, with some exceptions, most of the countries with the largest predicted losses of suitable habitat for mammals are in Africa and the Americas. African and North American countries were also predicted to host the most species with large proportional global declines. Most of the countries we identified as future hotspots of terrestrial mammal loss have little or no overlap with the present global conservation priorities, thus confirming the need for forward-looking analyses in conservation priority setting. The expected growth in human populations and consumption in hotspots of future mammal loss mean that local conservation actions such as protected areas might not be sufficient to mitigate losses. Other policies, directed towards the root causes of biodiversity loss, are required, both in Africa and other parts of the world.
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Future of Agriculture 165: Irrigating Confidently with Lee Addams of CropMetrics
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Lee joins me today to share his passion for improving water irrigation efficiency as well as water sustainability. He describes how he became interested in water irrigation and what led him to work with CropMetrics. He explains how their system works and how it can benefit growers. Lee also discusses what a transaction would look like with a farmer and how they convince them to join.
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Gagnolet, Tamara
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Gale 1975.pdf
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FIN-GEN
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Gale Academy of Sciences.pdf
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TRB Library
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FIN-GEN
