Like River and Lake, a cool, refreshing modern water-related choice. 

If you prefer the woods to the ocean, you'll want to name your son (or daughter) Beech instead of Beach.

Beech

Bowen is a Celtic surname representing two separate Celtic strains, one Welsh and one Irish, and entered the US Top 1000 for the first time in 2011.
 Football Hall of Famer Drew Brees named his son Bowen, as did a recent reality show couple looking for the perfect name to 'brand' their baby. It does have the appealing nickname Bo.
 
Alternatively, this is also a Chinese name, combining Bo and Wen, in which case the meaning would be 'wave of writing" or "wave in literature".

Bowen

Cedar is, like Ash, Oak, Pine and Ebony, one of the new tree/wood names that parents are starting to consider; this one is particularly aromatic.
 In the Bible the cedar is mentioned in Psalm 92:12: "The righteous shall flourish like the palm tree and grow like a cedar in Lebanon." The Lebanon  Cedar was used to build King Solomon's temple in Jerusalem, and there are now several hospitals called Cedars of Lebanon, plus a U2 song by that name.
 A contemporary bearer of the name is the jazz pianist Cedar Walton.

Cedar

Echo

More unusual than Forest or Forrest, Field is a nature name that is simple, evocative, and fresh--sort of the male equivalent of Meadow.
Field and Fields are both relatively common surnames, noted bearers including department store owner Marshall Field, poet Eugene Field (Wynken, Blynken and Nod) and actress Sally. Those with the plural include W.C. Fields, cookie company founder Debbi, and entertainers Gracie and Kim Fields.
 Fielding is a very usable extension.

Field

It feels like Finch should be a modern bird name that's as popular as Wren or Lark, but that's not the case - so it's one to consider if you're looking for a nature name that's familiar but rare. 

These colorful birds have made big contributions to science: the Galápagos finch played an important role in forming Darwin's theory of evolution, and the zebra finch has helped our understanding of how birds learn songs. 

Finch is also a surname belonging to, amongst other admirable people, the family in To Kill a Mockingbird.

Finch

As a member of two trendy name categories, animal and occupational, this name broke into the Top 1000 in 2004 and would make a nice tribute to an angler Grandpa.
 The best known bearer, Fisher Stevens, pulled a switcheroo on his birth name Steven Fisher. Fischer (another possible spelling) Black was a distinguished economist.
 Fisher is a fairly common surname, whose bearers include the family of Eddie, Carrie, and Joely; actress Isla; food writer M.F.K. Fisher; and two legendary cartoonists: Bud Fisher, creator of "Mutt 'n' Jeff," and Ham Fisher, who invented Joe Palooka.

Fisher

Fleet is one of the uncountable number of new word name possibilities, and a particularly cool choice at that.  Connoting speed, Fleet beats Rush any day.  Might be short for Fleetwood, but we prefer it on its own.

Fleet

Jasper originated as a variation of the Latin Gaspar, which ultimately derived from the Persian word ganzabara, meaning "bringer of treasure." As a given name, Jasper’s etymology is unrelated to that of the gemstone, which comes from a Semitic word meaning "speckled stone." Jasper is the usual English form for one of the Three Wise Men who brought gifts to the infant Christ according to medieval tradition and appears in the Bible as a reference to the stone itself in Revelations 4:3.
 
Jasper has a lot going for it—it's been rocketing up the ranks in the US, after long being considered a posh and charming name in England. Distinctly masculine, Jasper represents a variety of quartz—one of the few gem <a href="https://nameberry.com/boys-names">names for boys</a>—and is the first name of the great modern artist Jasper Johns. Our only caveat: Jasper is a favorite of a lot of hip parents, and has gotten even more popular since its strong appearance in the Twilight books and movies.
 Jasper has considerable literary cred as well, appearing in works by Sir Walter Scott, James Fenimore Cooper, Thackeray, and Thomas Hardy--as well as Stephenie Meyer. 
 Casper/Caspar is the German version.

Jasper

Jute

Kite

Evocative modern unisex choice brought into the spotlight by actress Lake Bell. 

Lake

Lane is a recent hit name, that could be used for either gender, but is much more popular for boys. It's a surname that projects the pleasant picture of narrow, tree-lined country roads.
 Holding steady between Number 200 and 300 in the US Top 1000 for more than a quarter century, Lane might be considered a modern classic for boys.
 Metallica's Lars Ulrich used the Layne spelling for his son.

Lane

The nature boy version of the Scandinavian Leif, which actually means "heir". In the creative-naming Phoenix family, Leaf is the former name of the actor we know as Joaquin.

Leaf

Originally a nickname for someone who loved to sing or whistle, Merle is sleek but gentle, with a hint of great grandpa about it..

Merle

Miro

Moon

Attractive, simple Japanese choice that, while not strictly unisex, could work even better for a girl, especially now that Kim Kardashian and Kanye West use it as the nickname for their daughter North. Nori is also the name of an edible seaweed used in wrapping sushi.
 
Nori also has roots as an Old Norse name, either a derivative of Nórr, meaning "north," or the word nori, referring to a small person.

Nori

There's a football player called Pepper (born Thomas and given the childhood nickname for sprinkling pepper on his cereal) Johnson -- but this sounds more like the name of a cheerleader. 

Pepper

Worthy sibling for Oak, Elm, Juniper, and Spruce.

Pine

Mostly feminine, though "Office" star Rainn Wilson gives it a slight masculine twist.  You might also use this as a short form of Raines.

Rain

Make that bird name, and while it does work for both genders, it's far more popular for girls, via Raven Symone. 

Raven

The Reid spelling is the most popular by half, probably because it feels more like a name than Reed, which looks more like a word. It's used occasionally for girls but this name is firmly in the boys' camp.

Reid

With its gentle sounds and earthy vibes, the name Rowan feels like a fusion of different styles. A word name, a surname, and a gender-neutral name, Rowan is rustic but trendy, blending the vibes of both Owen and Oakley. 
Just as it’s hard to fit Rowan into one category, it’s equally difficult to identify one definitive root. It could be considered an Anglicized form of the Irish name Ruadhán, meaning “little redhead” and it was used as an English surname before it became a given name. 
Alternatively, it could be linked to the rowan tree, whose name derives from Old Norse and means “to redden.” In folklore and mythology, rowan trees are seen as a symbol of protection and of life, adding extra meaning to Rowan. 
 To complicate matters further, some scholars identify Rowan as a girls’ name, deriving from Rowena and Rhonwen, meaning “famous friend” or “white spear.” This gives it solid credentials as a unisex name and lends it a slightly more rugged vibe. 
What is certain, however, is that Rowan has quickly become a stylish choice, chosen for over 3000 boys every year. Once an obscure name in the US, it rapidly climbed the charts during the 2010s and has now entered the Top 100 Boy Names for the first time. 
Rowan is popular in the UK, Canada, and the Netherlands too, but even more so among Nameberry users, where it ranks in the <a href=“https://nameberry.com/popular-names/nameberry/boys/allNameberry Top 1000”> Nameberry Top 30.</a> 
The most prominent bearer of the name is probably Rowan Atkinson, the British comic actor of Blackadder and Mr Bean fame. Other namesakes include the former Archbishop of Canterbury, Rowan Douglas Williams, and the Australian swimmer, Rowan Crothers. Pokémon fans and Sarah J. Maas readers might recognize it too as the name of a character in both the game franchise and in the Throne of Glass series. 
Gentle but powerful, stylish but not oversaturated, Rowan may well continue to climb the charts, so if you love Rowan but want to stray from the trends, Ruan, Sylvan, Lorcan, Lennox, Wren and Sloan might inspire you.

Rowan

Fits many criteria sought by modern parents: it's short and strong, with intimations of wisdom as well as fragrant herbal properties.  At this point, Sage is given about a third of the time to boys.



Sage

Sorrel is a gentle, amber-hued herbal and autumnal name that's used most often to describe the color of a horse. Sorrell is a variant spelling. Both make excellent <a href="https://nameberry.com/list/351/names-for-autumn-babies">names for autumn babies</a> and can be used for either gender.

Sorrel

Though some may find such names rather harsh and severe, increasing numbers of parents are gravitating toward this kind of flinty, steely, stony single-syllable name. 
 Many know the name via the distinguished TV newsman Stone Phillips; another bearer is Pearl Jam lead guitarist Stone Gossard. And yes, both were given the name at birth.

Stone

Sable

Sparrow

Highly unusual as a baby name for either gender, Yarrow is an herb that grows wild and has long been used for its medicinal property. It's named for the mythical Achilles, who was said to carry yarrow into battle.

Yarrow

tammylou's list "Nature for boys" of 33 great name ideas: Bay - Yarrow!