Zeke stops by. “Hey, I’m cleaning out my rig. Could you use some leveling blocks?”

I hope my dismay doesn’t show. Those things are huge. They can’t be tucked into odd corners like the 2×4’s I use now. “Thanks, but I’m set.”

“Greg doesn’t want them, either,” Zeke mourns, and wanders back to his van.

We are camped in the Sonoran Desert, where Arizona, California, and Mexico meet, and even the landscape doesn’t want extra baggage. Volcanoes shaped this land, spewing shrapnel across hundreds of square miles. Bare, mineral-rich crags surround broad, flat stretches of crushed-stone “desert pavement.”

Threaded through this moonscape are sandy washes, or bajadas. They channel rain from higher, harder ground, and they sing with greenery—palo verde and ironwood trees draped with mistletoe, creosote bushes, brittlebush waving with cheery yellow flowers, the ivy-like desert star vine. On their verges, cholla and saguaros grow. Lairs large and small line their banks.

If you were to ask me whether the land were hospitable or barren, I would not give you the same answer two days running.

Meanwhile, I’m in a honey drama. Don, the most community-minded man I’ve ever met, likes to buy things in bulk to give away. He picked up six 1-gallon jugs of honey from a beekeeper in Montana, with a long story to boot, and he’s unloaded one of them on me.

“You can give it to people in the caravans,” he says before high-tailing it away. “You’ll meet people that way.”

Sure, I’ve met people. But they’re all nomads living in tiny spaces, and none of them keeps spare containers around just for fun. Eventually I buy some jars, divvy up the honey, and crank up the sales pitch, part forlorn waif, part carnival barker. After a couple of months, it’s all gone except one jar. Tess refuses it—again—and rolls her eyes.

“I’m just selfishly trying to give it away,” I confess.

“I know you are,” she says with a knowing grin. “And I’m not having it.”

A year later, Evan and Zeke still have their jars, completely full. What did I give them, really? This small thing required that they give up a greater resource—space. My gift to them really gave a resource I wanted back to me.

I’ve wondered since then about what gift-giving means. The desert has been a good companion, because plants here don’t want unnecessary things. Not even leaves. Leaves need too much water and offer too much surface area to sun and wind. They are luxuries that cost more than most desert plants have to give.

Many plants here are drought deciduous, dropping leaves during dry spells and photosynthesizing in other ways. The palo verde (or “green stick”) tree, for example, keeps chlorophyll in its branches. Leaves are just a nice perk after rain. The branches grow thickly. Those, too, can be discarded during drought, and the ground beneath an older tree is often littered with deadwood.

Those dense branches, that deadwood—they matter. Palo verdes are nurse plants for saguaros. Only one in a thousand saguaro seeds will find the right conditions to sprout, and a seedling needs eight years to grow an inch tall. The first blossoms appear at age 35, the first arms at 50 or older. These are slow-growing giants, and to mature they need the water that lingers in shade, and shelter both from winter cold and summer sun. Palo verdes give them that.

Nurse trees die younger than their more “selfish” peers, as the growing saguaros develop a grown-up thirst and drink water the trees need. What did the palo verdes’ gift cost them?

And why, if sheltering a saguaro will kill them, do palo verdes do it? Trees have ingenious ways of defending themselves. They can produce repellant chemicals, drop leaves that smother rather than nurture, use the vast network of underground fungi to share nutrients only among their own kind. The palo verde protects its tender bark with thorns. Why not protect its most precious resource—water?

Since Darwin, we assume all species compete. I wonder if that assumption says more about humans. Our perspective on ecosystems and how they thrive is perhaps too modeled on our economies. We have no way of knowing what a tree “knows,” or what decisions it makes. What if a palo verde likes to cooperate?

The saguaro is a “keystone” species of the Sonoran Desert—a plant that carries the health of the entire desert on its shoulders. Between its fruit, flowers, and spines, it provides water, food, shelter, and nesting sites for a disproportionate number of species. The bees and bats that pollinate its flowers also pollinate the palo verde’s. Maybe the palo verde perceives and values the desert as a whole more than we humans perceive and value even our own kind. Maybe it is willing to share a truly precious resource for the greater good—even to the point of death. Is that a selfless gift? Enlightened self-interest?

Dee got the wrong water. Instead of the filtered, salt-free water we all buy for drinking, she tried the free well water. It’s potable, but acrid with minerals. “It tastes so bad even the dog won’t drink it,” she says in disgust.

My eyes light up. “I planned too much water when I built my rig and was thinking of getting rid of a jug. Do you want it?”

“Sure!”

I return gleefully with a 2 1/2-gallon container. Dee takes it with pleasure. “Let me empty this into my own jug, and I’ll give yours back.”

“No need,” I say, backing away. “Just keep it.”

Later, I’m ashamed. Dee lives in a minivan, for crying out loud. The next time I see her, I apologize. “What did you ever do to me, to deserve me foisting that container on you?”

She laughs. “It actually fits better in the space I have. I’ll take my old one to Goodwill. Hey, you couldn’t use some towels, could you? I have too many.”

“No! Thanks, though!” I back away again. Fast.

If you ever want to see selfish gift-giving in action, hang out with a nomad who’s cleaning house. In other ways we give freely—dog-sitting, watching over a campsite, picking up a few groceries in town. But you can tell where we consider ourselves rich and poor, because we do not give things from full and generous hearts, wanting nothing in return. Noooo. We give in desperation. We want to free up a scarce resource. If we help someone in the meantime, well, isn’t that a nice win-win?

So I wonder more largely, in this landscape of dearth and plenty, where do we consider ourselves rich or poor? When are our gifts gifts—true hospitality of the heart, from a place of plenty? When are they selfish gifts of dearth—the need to receive something in return, whether a resource or a pat on the back, the feeling of being a good person, of being needed or thanked?

To me, the palo verde symbolizes gift-giving as pure celebration of life: The desert is good, so let’s keep it going. The gain to the desert—and all palo verdes—is worth the loss of one life, because Life is good.

I don’t know that such drastic measures are called for from us. But I don’t know that they’re not. Where are we willing to give beyond our resources of time, energy, capacity—from dearth and generosity? What will we let giving cost us?

When, in the ecosystems of our lives, is that cost worthwhile?