Let’s say that the significant difference between a wood deck and a wood landing is the vertical clearance under the walking surface. You can stand up or nearly stand up under a deck, but you have to crawl under a landing.
One concern with the clearance under landings is that they are attractive to small animals. Cats, skunks and raccoons become curious about spaces not much taller than they are. And sometimes they look for seclusion when they are injured or terminally ill.
To prevent small animals from exploring under a landing, it’s tempting to close off this space with a wire screening or wood lattice or even wood siding. My expertise in animal behavior is limited to what I said in the paragraph above, but I’m not sure that enclosing the edge of a landing is a good idea for the animal, the occupants of the house or the landing. Some animals are strong enough to rip a hole in a screen or mesh if they are determined. If the mesh is rusty or the lattice is weakened with rot, getting through it is that easier. Wood siding cuts off the ventilation that the wood framing needs for longevity. If screened or louvered vents are installed in the siding, you’re back to the same issue as you were with wire mesh.
So my recommendation is to leave the landing edge open. Small animals who explore under the landing won’t get trapped because they can escape the same way they got in. The framing gets good ventilation, and, if an animal does die under the landing, the body can be removed from the edge.
Think about landscaping the landing edge with foundation planting at the perimeter to screen the gap between the grade and the landing surface from view. Or you can place plants in tubs or boxes set on the landing surface and allowed to cascade over the edge. Just don’t put in a fixed barrier here. It’s easier to maintain landscaping than a stiff barrier that you may come to regret.