to identify the specific person a set of fingerprints belongs to.

And we can do something similar with the various species of plants and animals out there – even

though most of them don't actually have fingers.

Hi, I'm Kate and this is MinuteEarth.

The kind of fingerprints I'm talking about start not with fingers, but with light.

When light hits, say, a pine tree, certain wavelengths of light reflect off the tree.

Some of these reflected wavelengths are ones we humans can see, but others are in the invisible

part of the spectrum.

If you could get a snapshot of all the light – both visible and invisible – that a

pine tree reflects, you'd come up with this: what scientists call the species' “spectral

fingerprint.”

Let's compare that to the snapshot for a different tree species nearby – say, a magnolia.

At first glance, the spectral fingerprints of the two species look similar, just like

the actual fingerprints of two people.

But – like the tiny differences in those fingerprints' swirls and whorls – there

are tiny differences in how the two tree species reflect light, thanks to their slightly different

chemical composition, crown and microscopic structure, water content, and more.

Since all tree species vary slightly in these kinds of characteristics, each species of

tree has a distinctive spectral fingerprint.

Which means it's possible, based on a tree's spectral fingerprint alone – to determine

its species…and that has tree-mendous implications for our planet.

Tree-cologists can run fancy images from planes and satellites through computer programs trained

on the spectral signatures of thousands of different tree species, and the programs can

identify the species that live there.

The programs can even find trees that aren't doing well – and figure out the particular

reason they aren't doing well; like, an oak tree is supposed to have a fingerprint

like this.

If it has a fingerprint like this, it's drier than it should be, suggesting drought.

If it has a fingerprint like this, it's having trouble photosynthesizing – it probably

has a disease.

You may have noticed that we've only been talking trees so far.

See, scientists have been working with trees' spectral fingerprints for a particularly long

time, so they've been able to amass a big library of different tree species' fingerprints

and start putting them to use.

But as far as we know, every species – from corals to fish to polar bears – reflects

light in a slightly different way, and therefore has a distinctive spectral fingerprint.

So scientists are exploring other branches of the tree of life; they're working to

document the unique fingerprints of more and more species, and figure out what we can accomplish

with those fingerprints….

…things like finding polar bears on vast stretches of ice and assessing the health

of huge underwater reefs.

Which are, of course, tasks that are already possible without spectral fingerprints.

But they generally require a lot of slow, difficult, in-person research, often in places

where it's very hard to work.

Spectral fingerprints are helping scientists collect data about specific individuals and

species more quickly and easily than ever before – as are other remote approaches

like trail cams, GPS collars, environmental DNA, and acoustic monitoring.

With these kinds of strategies, maybe we'll be able to save certain plants and animals

before all we have left of them is their fingerprints.

One group working hard to use spectral fingerprints to study and conserve biodiversity is the

ASCEND project, a National Science Foundation-funded Biological Integration Institute led by Jeannine

Cavender-Bares, Phil Townsend and Peter Reich.

The ASCEND team is using spectroscopy in all sorts of ways, from finding and mapping sick

trees to prevent the spread of disease, to tracking biodiversity over time to see if

efforts and policies are making a difference.

In addition to advancing knowledge, ASCEND is training the next generation of integrative

biologists to understand how life's variation is connected across scales and impacted by

global change.