I’m from the states and I took this as “national park” (or perhaps state) land. It’s land intended for ecological conservation.

It could mean anything from private land with an easement to prohibit building on it to a National Park, depending on context and jurisdiction. It's just a non-specific term for "land that is conserved in some way."

The nomenclature is really messy across countries and even sub-country entities. The Portuguese language Wikipedia even highlights the mess:

Nomenclature diversity across countries. // Some surveys estimate protected areas in different countries and regions are called by at least a hundred names, and not uncommonly countries have their own categories of protected spaces, roughly similar to the protected space concept defined by the IUCN.

From that I guess the restrictions associated with those spaces also change, and in some you aren't supposed to remove local fauna and/or flora, creating situations like in the meme (removing invasive species is against the letter of the rule, but within the spirit).

Conservation land, in my area, is just land designated to not be developed. It might be privately owned and designated "conservation land* for tax benefits, or owned by the town, or what have you. Sometimes housing developers will designate part of their land plot as "conservation" for some benefit from the town (like taxes or zoning easement).

Guess it's lost in translation.

Conservation land is a protected wild area. Sometimes it's what we refer to as "the woods," and not properly marked from a local standpoint.

In my region, there are many county and state (vs federal in US) parks, with recreational areas and rules about how to interact with the wildlife. Greatparks.org.

There are also private nature preserves, and those appear to us as hiking trails. https://www.cardinallandconservancy.org/ is an example.

There are also smaller conversation areas. I know of a little bog about the size of a football field with a little sign saying it is maintained by the local college.

Try using context clues for a brief second