On January 27, 2021, President Joe Biden signed an executive order called “Executive Order on Tackling the Climate Crisis at Home and Abroad”. It included the following text: “The Secretary of the Interior, the Secretary of Agriculture, the Secretary of Commerce, through the Administrator of the National Oceanic and Atmospheric Administration, and the Chair of the Council on Environmental Quality shall, as appropriate, solicit input from State, local, Tribal, and territorial officials, agricultural and forest landowners, fishermen, and other key stakeholders in identifying strategies that will encourage broad participation in the goal of conserving 30 percent of our lands and waters by 2030.” As an agricultural / forest landowner, Black Squirrel Farms is delighted to be considered a key stakeholder in an issue of national significance and we stand by, ready to receive a call and provide input on the matter.
Additional text in the executive order indicates that stakeholder input is intended to help develop a report, due within 90 days of the order date, which will recommend steps that the United States should take to achieve the goal of conserving at least 30 percent of our lands and waters by 2030. Forty-seven days have already passed without us receiving a call. Because the schedule is getting tight, we decided to expedite providing our input by publishing this convenient and easily sharable web page.
From our perspective, we appear poised to do the wrong thing for the right reasons. Often, when land conservation is discussed, conserving the land is a side issue with the real objective being to conserve the natural processes or resources that the land supports, retains or provides. “Acreage” is not a direct indicator of conservation value. Not all acres have the ability to contribute equally to conservation goals, whether that goal is biodiversity preservation, related to soil carbon or carbon sequestration or involves the provision of critical ecosystem services. Location matters. Geology matters. Biology matters. Climate matters. Land management decisions and practices matter. To avoid confusion, we aren’t against conserving land. We are against using indirect indicators to measure progress against goals.
A direct measurement of conservation would assess the robustness of ongoing trophic processes key to healthy earth system functioning. Because directly measuring conservation would involve understanding which species are present, at what levels and how populations act, interact, and change with time, direct measurement of conservation at the national landscape level appears unrealistic at present. That said, measuring the amount of energy available on an ongoing basis to run the trophic processes that result in conservation appears achievable. A conservation target to ensure that sufficient energy remains available to support ecosystem functioning, which is in practice a guaranteed living wage for ecosystems, makes sense. The metric which could be used to set and monitor such a goal is called “Net Primary Productivity” and it isn’t new. What is relatively new is that NASA and others feel that they can map it using calibrated high-resolution satellite-collected data.
Broadly, Gross Primary Productivity (GPP) is all the solar energy that plants chemically capture every year. Net Primary Productivity (NPP) is the energy plants capture and don’t use for respiration. Therefore, NPP can be approximately conceptualized as the amount of new organic matter created by plants each year. This plant material, which is in effect chemically captured energy, then powers the rest of earth’s complex food webs. Just as a car needs fuel, ecosystems need NPP. The idea of NPP can be extended to differentiate between potential NPP and actual NPP. Potential NPP is the solar energy that local climatic and geologic conditions suggest plants should be able to capture whereas actual NPP is the solar energy that plants actually do capture. Potential and actual NPP can be different for lots of reasons and some, like wildfires or diseases, are natural but at a high level, much of the difference between potential and actual NPP is related to the impact of human-induced landscape changes. To illustrate the difference between actual and potential NPP, assuming equal climate and geology, a parking lot just won’t grow as much plant material each year as a grassland. The parking lot and grassland could have the same potential NPP but a very different actual NPP.
If human impact on NPP was restricted only to how landscape modification impacts plant growth each year globally, comparing potential and actual NPP would come close to describing human impact on the ecosystem’s energy budget. However, just as ecosystems consume NPP to support ongoing functioning, so do people. We consume NPP directly as food, livestock feed, fuel, fiber, lumber and more. Therefore, to understand human impact on NPP, we need to consider both the NPP whose growth we suppress through landscape changes plus the NPP which is consumed to support human purposes. Human appropriated net primary production (HANPP) is term used for this aggregate impact. HANPP is the fraction of potential NPP that people use (such as, we eat it or burn it for fuel), co-opt (such as, we feed it to livestock then eat the livestock) or forego (such as, this land used to have the net primary productivity of a mature forest and now has the net primary productivity of a highway). How much of global potential NPP are people already using? This paper estimated that the global HANPP level had already reached 23.8% of potential NPP by 2007 and this is not the highest estimate published. The implication is that the complex webs of millions of non-human species that rely on NPP now operate with only about 75% of the energy that was available to them just a few hundreds of years ago. And while this is a shockingly high rate of NPP diverted to support a single species over the course of just a few short centuries, keep in mind that HANPP is indicative only of the bioenergy that people use. Human consumption of energy from sources other than biomass is not considered.
If there’s an acronym for human appropriated NPP, there should be an acronym for NPP not appropriated by humans. Let’s call this “ecosystem available” NPP (EANPP). Broadly, EANPP should represent the ongoing energy available to power the functioning of earth’s natural biological systems. In terms of setting a conservation target, we’d prefer that a “minimum EANPP” target be set rather than a fixed amount of land designated “conserved”. Certainly, the need to protect natural ecosystem functioning is real and immediate. This relatively recent study revealed that farmed poultry now makes up 70% of all birds on the planet, meaning that only 30% of all birds today are wild. This same study found that 60% of all mammals on Earth are livestock, mostly cattle and pigs, 36% are human and just 4% are wild. It certainly appears that a planet full of wild species is turning into a planet full of domesticated food animals and crop plants as a result of human activity. If that isn’t the world we want to live in and hand off to future generations, taking intentional steps to reverse this trend is necessary.
Even though a minimum EANPP wouldn’t measure the quality of natural biological functioning supported, it would make sure that the energy available to accomplish such functioning remains available. Deciding whether land should be considered “conserved” and therefore count towards a fixed acreage target will always be a minority exercise. Land ownership, like wealth, is highly concentrated. According to this 2016 paper by New York University economist Edward Wolff, the wealthiest 1 percent of US households owned 40 percent of the nation’s non-home real estate just a couple of years ago. The people most likely to be involved in a national discussion about conserving a fixed number of acres are landowners, government representatives and people who care deeply about the issue. Endless squabbling amongst this minority about the definition of “conserved land” and how conservation should be rewarded is a plausible outcome. It’s equally plausible that any program implemented would end up preferentially “conserving” acreage that doesn’t have economic value for much else, likely a non-optimal conservation outcome. If broad participation in delivering a conservation objective is desired, a stated objective in the executive order, there will clearly need to be a way for people who don’t own land to contribute. Anyone could help deliver a minimum EANPP. On every acre and associated with every lifestyle, opportunities exist to make things better or worse for non-human species. Actual NPP can even exceed potential NPP. Just consider that 20-50 times more lettuce can be grown in a greenhouse than a field. Continued advances in agricultural and food management technology can increase the size of the NPP pie or reduce HANPP levels in ways we have not yet imagined. Limiting the conservation solution space to “this land shall be designated as conserved or not”, even if many factors are taken into consideration in order to make such a decision, is far too narrow and will at best deliver a sub-optimal result at high cost.
The reason we would prefer a conservation goal expressed in terms of minimum EANPP vs. land area conserved becomes clear by looking at our site. On our 8.5 acre site is mostly a second-growth forest with an unusually high proportion of black walnut trees, an unusually high proportion of ash trees, some oaks, a few basswood trees, an experimental planting of hazelnuts, a couple of maples and an understory comprised of grass and a mix of other herbaceous and woody native and non-native plants common to the region. We are in the process of constructing a small building to support black walnut shelling operations. Constructing the building required the construction of a driveway that, while permeable, will not support plant growth to a pre-driveway level. We’re hoping to install ground-mounted solar onsite in 2022 or 2023. Our ash trees are in the process of being killed by a regional emerald ash borer infestation that we are powerless to prevent. The actual NPP of our site has degraded under our control. Would our site qualify as “conserved”? Probably not for a fair definition of the word conserved. On the other hand, does this site have more ecosystem value than it would if it was used as a cornfield? Absolutely. Over the next few years, can we figure out how to make our site better for people and planet? We certainly believe so. Do we want to be limited in the options that we can consider to try to achieve this goal? Of course we don’t. And this is why recognition of “partial conservation credit” needs to be possible not just for our site but for all sites. The traditional idea of conservation is “hands off” and binary (yes/no) with no easy way to recognize partial credit. Figuring out how to maintain or increase EANPP is “hands on” with a broad associated set of possible solutions. Like pretty much everything else, degree of human impact on the landscape is a continuum, not a binary state of impacted / not impacted. It is the rare site that provides absolutely nothing for people or absolutely nothing of ecosystem value; most sites provide a mix of both. Could our site participate in a goal of conserving a fixed number of acres? Probably not, we intend for our site to be working land. Could our site participate in a conservation goal of making 80% of potential NPP ecosystem available? We’d certainly try.
If we didn’t agree that the issue was important, we would not have taken the time to express a view. If we didn’t think that there was at least some chance that our view would find additional support, this post would not have been published. We think there are probably a lot of sites out there like ours, where expressing a conservation goal in terms of EANPP allows them to participate in delivering a conservation solution without going so far as requiring the site to be considered “conserved”. We now consider our civic duty discharged as we have provided input on the matter under discussion. We encourage others to do likewise.