(select title for link to video on CCTV)

The Chinese government is undertaking a huge tree planting program in an effort to halt desertification.  At first glance it seems like a great idea, but the reality is much more complicated.

Tree planting is a catchy and buzz-wordy kind of policy that generates lots of positive emotions, but the reality is that planting monocultures of non-native trees does not reverse desertification. Usually they require massive irrigation or else they all die—right after the shiny local government official photo-op. And these trees are not as efficient at stabilizing sand dunes as the native vegetation. One positive practice that this videos captures, but does not describe in this video, is the creation of straw “checkerboards” on the dunes. This stabilizes the sand and allows the native early sucessional species to re-establish. More of that kind of restoration would do so much more to halt the spread of desertification in China…. but a massive strategy to plant straw just doesn’t sound as catchy as planting trees.

While desertification in purported to be irreversible, there are promising recoveries underway at a handful of long-term livestock exclosures around the world.  Perennial grass cover is, slowly but surely, returning to these sites.  The purpose of my dissertation is to find out how, and why it has taken nearly half of a century after grazing was removed.

When viewed from above, it is easy to discern the cross-fence differences in grass cover at the recovery site located in southeastern Arizona.  The area inside the fence appears much more grey, due to the higher cover of perennial grass plus the build-up of senescent grasses.

before & after

I was finally able to take a short trip to Da Xing Guo, a national level protected area.  It is one of the only places in this part of Inner Mongolia where the original grasslands are still intact.  This site is situated alongside a small ravine (where you can find one of the only examples of original forest type).  This ravine is probably the reason the grasslands are still here—  At the turn of the century people avoided it because it was home to famous bandits. (!!)  After that, the Japanese army camped out there. Eventually it was protected by the government.  It is now a popular destination for Chinese tourists.

The grasslands at Da Xing Guo represent just a tiny piece of the formerly extensive grassland habitat.  It is hard to imagine that this second pic used to look like the pic above. Miraculously, mostly due to intensive management, the total area of shifting dunes in the region has decreased over the past ten years.  However, climate change predictions for this area call for hotter winters and drier summers, so it remains to be seen if this reversal is sustainable over the long term.

memorial

this gravesite sits in the middle of one of my research plots.  it might seem inappropriate to have researchers traipsing back and forth around it all the time, but the family of the deceased is actually quite pleased.  these research plots were established in 1997 in order to monitor vegetation succession and restoration with removal of livestock.  at the time the fence was established this area was very overgrazed and the wind was eroding the sand around the grave.  20 years later the vegetation has stabilized the site, and in fact, the site is now the recipient of wind-blown sand and dust from the adjacent cropland.

greener pastures

livestock headed to the nearby communal grazing area.  the area to the left is fenced by the landowner from the nearby village. he grazes his livestock there for a few months each year, and then the vegetation is allowed to recover.  by now (almost august) the vegetation inside the fence is noticeably taller and more diverse than the communal area, where the only plants taller than 5cm are unpalatable species and thorny shrubs. but still, even with the fencing and the limited grazing, there is little perennial grass; it is mostly early-successional weedy species.

on fencing

I spent last week in Beijing at the International Congress on Conservation Biology, the SCB’s annual conference. I went to an all day workshop on rangeland management that was specifically geared toward issues here in China, and more specifically on desertification.

there was a lot of hemming and hawing about causes and consequences, but a lot of the land degradation can be blamed on two key issues: changes in land tenure and population expansion. In the early 1980s China instituted the “double contract” system of land tenure, which subdivided the formerly communal rangelands of northern China (as well as other regions) into individual land holdings by household. This was part of a movement (still underway) to settle the nomadic pastoralists into formal villages. These policies had a whole list of cultural and social ramifications, but they also kick-started the land degradation by concentrating grazing into small fenced areas.

within certain circles today there is a backlash occurring against fencing. many of the researchers at this workshop were reporting on all of the negative consequences of fencing, including that they impede the movement of wildlife.

but to me the issue seems much more ambivalent and site-specific, and depends on whether you are talking about fencing the cows in, or keeping them out.

in the region where i am working heavy grazing of the few remaining communal grazing lands has degraded many of them into mobile sand dunes. however, after only a few years of fencing the livestock out, vegetation cover increases dramatically and stabilizes the sand once more.

the site in this pic was almost entirely bare sand fifteen years ago, but now it is an oasis of plant diversity in a landscape mosaic of corn fields, poplar plantations and degraded former grassland. however, even after fifteen years of restoration, very few of the original grasses have recovered on the site.

I’ll have more on this issue in the future… the issue is too complex for just one post.

encroaching sandy land

the road through this region was recently improved by the local government.  in an effort to secure their investment, they are taking huge steps to stabilize the moving sand dunes to prevent them from burying the new road.  in the foreground you can see the checkerboard of maize stalks that they used to slow the erosion and hold everything in place long enough to allow some vegetation to establish. this method can be quite successful; in sites nearby, dunes have been stabilized with this method in a period of several years.  however, this region of mobile dunes is quite extensive, and it is unlikely that any governmental effort will extend beyond the corridor immediately along the road. 

desertification step 2

in dry years, many farmers give up on planting crops.  this land was once grassland, converted to cropland (usually maize) and now left bare for this growing season.  the bare soil is sensitive to the high velocity winds in this region, which erode the soil and carry it far and wide. even if the fields are planted in summer, the soil is bare during the winter when the winds are the strongest.

these fields are adjacent to one of my study plots, and the deposition of sand has been so intense that it keeps burying the fence posts.  the director of the research station tells me that they have had to dig out and reposition the fence posts twice in the past ten years.

there is so much dust in the air here that on windy days (most days) i sweep my floor at least twice and cover my laptop keyboard when it is not in use.

(desertification step one)